HR, 20-12-2019, nr. 19/00135 (Engels)

In its judgment of 9 October 2018, The Hague Court of Appeal (abbreviated hereinafter as the Court of Appeal) affirmed the judgment of The Hague District Court (abbreviated hereinafter as the District Court).1.Section 2 of the Court of Appeal's judgment is premised on all of the facts established in paras. 2.1-2.78 of the District Court's judgment of 24 June 2015. In addition to this, the Court of Appeal made its own findings of fact in paras. 3.1-3.7 and at 4.26 of its judgment. Those findings of fact were a work in progress up to and including 28 May 2018, the day on which the oral arguments on appeal were concluded. Finally, the Court of Appeal set out the most important elements of the overview of facts, and the conclusions it drew as a result, in para. 44.2.

In this first chapter, we will provide only a brief recitation of the established facts as an introduction. We will discuss the relevant facts in more detail when addressing the individual complaints in the grounds for cassation. Where necessary, we have added sources for the facts established by the Court of Appeal.

The greenhouse effect

(i) Since the beginning of the industrial revolution,3.mankind has been using energy on a large scale: energy that is primarily obtained by burning fossil fuels (coal, oil and gas), thus releasing carbon dioxide. This compound of carbon and oxygen is generally referred to by its chemical formula: CO2. Part of the CO2 that is released is emitted into the atmosphere, where it remains for hundreds of years or more and is partly absorbed by the ecosystems in forests and oceans. This absorption capacity is continuously decreasing due to deforestation and the warming of the oceans.

(ii) CO2 is the most significant greenhouse gas and, in tandem with other greenhouse gases, it keeps the heat radiated by our planet in the atmosphere. This is called the ‘greenhouse effect’. The greenhouse effect increases proportionately with the amount of CO2 that winds up in the atmosphere, which in turn warms the planet at an increasing rate. It is important to note that the planet's climate system is slow to respond to the emission of greenhouse gases: the full warming effect of the greenhouse gases being emitted today will not be felt for another 30 to 40 years. In addition to CO2, other greenhouse gases include methane, nitrous oxide and fluorinated gases.

(iii) Concentrations of greenhouse gases in the atmosphere are expressed as ‘ppm’, parts per million. The term ‘ppm CO2 equivalent’ is used to express the total concentration of all greenhouse gases, in which respect the concentration of all of the other, non-CO2 greenhouse gases is converted into CO2 equivalents based on their warming effect..4.

Climate change and the 2ºC target

(iv) There is a direct, linear connection between greenhouse gas emissions caused by mankind, which are partly caused by the burning of fossil fuels, and the warming of the planet. The Court of Appeal noted that the average temperature of the planet is already approximately 1.1ºC higher than it was at the start of the industrial revolution. The current concentration of greenhouse gases in the atmosphere is approximately 401 ppm. In recent decades, worldwide emissions of CO2 have increased by 2% each year.

(v) The rise in the planet's temperature can be prevented or reduced by ensuring that less greenhouse gas is emitted into the atmosphere. This is referred to as ‘mitigation’. Measures can also be taken to anticipate the effects of climate change, such as raising dikes in low-lying areas. The taking of such measures is referred to as ‘adaptation’.5.

(vi) The climatology field and the global community long ago reached a consensus entailing that the average temperature of the planet may not rise by more than 2ºC in comparison to the average temperature of the pre-industrial era. If the concentration of greenhouse gases in the atmosphere has not risen above 450 ppm by the year 2100, there is a reasonable chance that this objective (hereinafter: ‘the 2ºC target’) will be achieved. In recent years, new insights have shown that the temperature can only safely rise by no more than 1.5ºC, which translates into a greenhouse gas concentration level of no more than 430 ppm in the year 2100.6.

(vii) When viewed in light of the maximum concentration level of 430 or 450 ppm in the year 2100 and the current concentration level (401 ppm), it is clear that the world has very little room left when it comes to the emission of greenhouse gases. The worldwide room that still remains is referred to as the carbon budget.7.The Court of Appeal held that the chance that the rise in temperature could still be limited to the target of 1.5ºC has become extremely slim.8.

(viii) Warming of more than 2ºC in comparison to the pre-industrial era would cause inter alia: flooding as a result of the rise in sea level; heat stress as a result of more intense and longer-lasting heat waves, increases in respiratory ailments associated with deteriorating air quality, droughts (with devastating forest fires), increased spread of infectious diseases, severe flooding as a result of torrential rainfall, and disruptions of the production of food and the supply of drinking water. Ecosystems, flora and fauna will be eroded and there will be losses in terms of biodiversity. As Urgenda has asserted and the State has not refuted, an inadequate climate policy will result in the second half of this century in hundreds of thousands of victims in Western Europe alone.9.

(ix) One striking aspect of all of this is that the increase in the concentration of greenhouse gases in the atmosphere could result in the climate change process reaching a tipping point, leading to an abrupt change in climate for which neither mankind nor nature can prepare. According to the AR5 report to be discussed below, risks increase ‘at a steepening rate’ at such tipping points under warming of 1 to 2°C (in comparison to the average temperature in the pre-industrial era).10.

IPCC reports

(x) The Intergovernmental Panel on Climate Change (IPCC) was created in 1988 under the auspices of the United Nations by the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP). The IPCC's objective is to obtain insight into all aspects of climate change through scientific research. The IPCC is not just a scientific organisation; it is an intergovernmental organisation as well. It has 195 members, including the Netherlands. Since its inception, the IPCC has published five reports with accompanying working group reports about the state of the art of climatology and climate developments.11.Particularly relevant to these proceedings are the fourth report from 2007 and the fifth report from 2013-2014.12.

(xi) The IPCC published its Fourth Assessment Report in 2007 (abbreviated hereinafter as: AR4). According to the District Court, this report stated that a temperature increase of 2°C above the level of the pre-industrial era will entail the risk of a dangerous, irreversible change in the climate.13.

(xii) After an analysis of various reduction scenarios, Chapter 13 of the report from the third Working Group of experts states that in order to be able to achieve a maximum volume of 450 ppm in the year 2100, the emissions of greenhouse gases by the countries listed in Annex I to the UNFCCC (including the Netherlands) must be 25% to 40% lower in the year 2020 than they were in the year 1990.14.

(xiii) The IPCC published its Fifth Assessment Report in 2013-2014 (abbreviated hereinafter as: AR5). This report established inter alia that the planet is warming as a result of the increase in the concentration of CO2 in the atmosphere since the beginning of the industrial revolution, and that this is being caused by human activities, in particular by the burning of fossil fuels and deforestation.15.In the AR5 report, the IPCC concluded that if the concentration of greenhouse gases in the atmosphere is stabilised at around 450 ppm in the year 2100, the chance that the global temperature increase would remain under 2ºC is ‘likely’, meaning higher than 66%. In this respect, it must be kept in mind that 87% of the scenarios included in AR5 were based on assumptions regarding negative emissions; in other words: the possible removal of CO2 from the atmosphere.

United Nations Framework Convention on Climate Change (UNFCCC) and the climate conferences

(xiv) The UNFCCC was concluded in 1992.16.The objective of this framework agreement is to achieve stabilisation of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system (Article 2 UNFCCC). Article 3 states the principles according to which the parties will allow themselves to be guided in achieving this objective.17.The parties to the UNFCCC are referred to as Annex I countries (including the Netherlands) and non-Annex I countries. According to Article 4(2) of the convention, the Annex I countries must take the lead, in an international context, in combating climate change and the adverse effects thereof. They have committed to reducing greenhouse gas emissions. They must periodically report on the measures they have taken with the objective of achieving, either individually or collectively, a return to the emissions level of 1990.18.

(xv) Article 7 UNFCCC governs the Conference of the Parties (hereinafter: ‘COP’). The COP usually meets annually at climate conferences. The COP is the supreme body of the UNFCCC, it being understood that in general, the COP's decisions are not legally binding.19.

(xvi) During the climate conference in Kyoto in 1997 (COP-3), the Kyoto Protocol was agreed between a number of Annex I countries, including the Netherlands.20.The reduction targets for the period 2008-2012 were laid down in this protocol. According to Annex B to this protocol, the then-Member States of the EU should apply the premise of a reduction target of 8% in comparison to the reference year 1990.

(xvii) The Bali Action Plan was adopted at the climate conference in Bali in 2007 (COP-13). The Bali Action Plan acknowledged the necessity of drastic emissions reductions, citing the aforementioned AR4. That quote regarded inter alia the page in the report of the third Working Group of experts for AR4 which contains the table (‘Box 13.7’) referred to in footnote 14 above, which states that if the Annex I countries wished to achieve the 450 ppm scenario, emissions of greenhouse gases would have to be 25%-40% lower than they were in 1990.21.

(xviii) No agreement could be reached during the climate conference in Copenhagen in 2009 (COP-15) regarding a successor to, or an extension of, the Kyoto Protocol.22.During the next climate conference in Cancun in 2010 (COP-16), in the Cancun Agreements (Decision 1/CP.16), the parties involved set the long-term target of maximising the rise in temperature at 2ºC in comparison to the average temperature in the pre-industrial era – along with the possibility of a more stringent target of a maximum of 1.5ºC. The preamble refers to the urgency of a major reduction in emissions.23.

(xix) In Cancun, the parties to the Kyoto Protocol stated that the Annex I countries had to continue to take the lead in combating climate change and that, given AR4, this ‘would require Annex I Parties as a group to reduce emissions in a range of 25-40 per cent below 1990 levels by 2020’. The parties to the Kyoto Protocol urged ‘Annex I Parties to raise the level of ambition of the emission reductions to be achieved by them individually or jointly, with a view to reducing their aggregate level of emissions of greenhouse gases in accordance with the range indicated by Working Group III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change’. In the ‘Cancun Pledges’, the EU countries as a group declared their willingness to achieve a 20% reduction by 2020 (in proportion to the emissions in the reference year 1990), and offered to achieve a 30% reduction if other countries were to undertake to achieve similar reduction targets.24.

(xx) During the climate conference in Doha in 2012 (COP-18), all Annex I countries were called upon to increase their reduction targets to at least 25%-40% in 2020. An amendment to the Kyoto Protocol was adopted in which the European Union committed to a reduction of 20% in 2020 in comparison to the emissions in the reference year 1990, and offered to reduce emissions by 30% if other countries were to undertake to achieve similar reduction targets. This condition was not met. The Doha Amendment did not enter into force.25.

The Paris Agreement (2015)

(xxi) In 2015, the Paris Agreement was concluded during the climate conference in Paris (COP-21).26.According to the Court of Appeal, the system of the Paris Agreement differs from that of the UNFCCC. The parties to the convention are no longer striving to reach global emissions agreements. Each contracting State will be called to account for its own responsibilities. The Paris Agreement stipulates that global warming must be kept ‘well below 2°C’ above pre-industrial levels, pursuing efforts to limit the temperature increase to 1.5°C above pre-industrial levels (Article 2). The parties must prepare ambitious national climate plans that become progressively more ambitious over time (Article 3).27.

The UNEP reports of 2013 and 2017

(xxii) Since 2010, UNEP has issued annual reports on the difference between the desired emissions level and the reduction targets to which the parties have committed: this is referred to as the ‘emissions gap’.28.The UNEP reports of 2013 and 2017 are particularly relevant to these proceedings. The 2013 annual report stated for the third time in a row that the parties had failed to fulfil their commitments and that greenhouse gas emissions had risen rather than fallen. UNEP also noted that the Annex I countries together had failed to achieve the emissions targets that were considered necessary to achieve the 25%-40% reduction referred to in the aforementioned Box 13.7 of the report of the third Working Group of experts for AR4. UNEP concluded that it becomes less and less likely that emissions will be low enough by 2020 to be on a least-cost pathway towards meeting the 2°C target. Although later reduction actions could ultimately lead to the same temperature targets, according to UNEP these would be more difficult, costlier and riskier.29.

(xxiii) In the 2017 report, UNEP stated that in light of the Paris Agreement, ‘enhanced pre-2020 mitigation action’ was more urgent than ever. UNEP noted that if the emissions gap that had been identified was not closed by 2030, it would be extremely unlikely that the 2°C target could still be reached. This was why, according to UNEP, more ambitious reduction targets were needed for 2020.30.

European climate policy: ETS Directive and Effort Sharing Decision

(xxiv) Article 191 of the Treaty on the Functioning of the European Union (‘TFEU’) sets out the Union's environmental targets. The EU formulated directives to implement its environmental policy. The ETS Directive is one of these.31.The abbreviation ‘ETS’ stands for: Emissions Trading System. This system entails that companies in the ETS sector may only emit greenhouse gases in exchange for the surrender of emissions rights. These emissions rights may be bought, sold or retained. The total volume of greenhouse gases which ETS companies may emit in the period 2013-2020 decreases by 1.74% annually until, in 2020, a 21% reduction is achieved in comparison to the year 2005.

(xxv) The Council determined that the European Union must reduce greenhouse gas emissions by at least 20% in 2020, 40% in 2030, and 80%-95% in 2050, measured in each case in comparison to emissions in the reference year 1990. Based on the Effort Sharing Decision32., it was determined within the EU that for non-ETS sectors, the reduction target of 20% in 2020 means that the Netherlands will have to achieve an emissions reduction of 16% in comparison with emissions in 2005.

(xxvi) According to current [meaning: at the time of the Court of Appeal's judgment] expectations, the European Union as a whole will achieve an emissions reduction of 26%-27% in comparison to emissions in 1990.33.

National climate policy and the results of that policy

(xxvii) Based on a 2007 programme entitled ‘Schoon en zuinig’ [Clean and economical], in the period 2007-2011 the Netherlands applied the premise of a reduction target of 30% in 2020 comparison to the emissions level in the reference year 1990. In a letter of 12 October 2009, the then-Minister of Housing, Spatial Planning and the Environment (Volkshuisvesting, Ruimtelijke Ordening en Milieubeheer - ‘VROM’) informed the Dutch House of Representatives about the Netherlands’ negotiations objective within the context of the climate conference in Copenhagen in 2009 (COP-15). This letter stated inter alia:

‘The total of emission reductions proposed by the developed countries so far is insufficient to achieve the 25%-40% reduction in 2020, which is necessary to stay on a credible track to keep the 2ºC target within reach.’34.

(xxviii) After 2011, the Dutch reduction target was adjusted to the EU-level reduction of 20% in 2020 (in other words, for the Netherlands, a reduction of 16% in the non-ETS sector and 21% in the ETS sector, each time in comparison to emissions in 2005); and of at least 40% in 2030, and 80%-95% in 2050, in each case in comparison to emissions in 1990.35.

(xxix) In the most recent Government Agreement (2017), the government announced that it would strive to achieve an emissions reduction of at least 49% in 2030 in comparison to emissions in 1990. According to this government agreement, the EU reduction target of 40% in 2030 was not sufficient to achieve the 2°C target, let alone the 1.5°C ambition laid down in the Paris Agreement.

(xxx) Dutch CO2 emissions per capita of the population are relatively high in comparison with other industrialised countries.36.Of the total volume of Dutch greenhouse gas emissions, 85% consists of CO2. Dutch CO2 emissions have barely decreased since 1990 and have even risen in recent years. In the period 2008-2012, the Netherlands achieved a reduction of CO2 equivalent emissions of 6.4%. The reduction is attributable to greenhouse gases other than CO2. In that same period, the fifteen largest EU Member States achieved an emissions reduction of 11.8%, and the EU as a whole achieved a reduction of 19.2%.

(xxxi) The District Court's judgment was premised on the Netherlands achieving a reduction in 2020 of 14%-17% in comparison to 1990 levels. On appeal, the Court of Appeal noted that in 2017, the Netherlands had been expected to achieve a 23% reduction in 2020, taking a margin for uncertainty of 19%-27% into account.37.This difference is largely attributable to a new calculation method which is more consistent with that used by the IPCC, as a result of which the theoretical reduction percentage is achieved earlier even though the situation is effectively more serious.38.In 2017, the most recent year prior to the disputed Court of Appeal's judgment, greenhouse gas emissions in the Netherlands had fallen by 13% in comparison to emissions in 1990.39.

The dispute in and out of court

Urgenda is a citizens’ platform (an NGO) with members from various domains in society . Urgenda is involved In the development of plans and measures to prevent climate change. Urgenda's legal form is that of a foundation under Dutch law, whose object according to its by-laws is: to stimulate and accelerate the transition processes to a more sustainable society, beginning in the Netherlands.40.Urgenda's position is that the State is doing too little – in the interest of preventing dangerous climate change – to mitigate global warming and keep the average temperature from rising by no more than 2°C in comparison to the average temperature in the pre-industrial era.

The government's care is directed at keeping the country habitable and protecting and improving the environment (See Article 21, Dutch Constitution). Since 2017, responsibility for the environment has been part of the duties of the Minister of Economic Affairs and Climate Policy.41.

On 12 November 2012, Urgenda requested the State to commit to reducing Dutch CO2 emissions as of 2020 by 40% in comparison to 1990 levels. The State denied this request on 11 December 2012.42.In these proceedings, Urgenda is requesting, to the extent relevant in cassation, that the State be ordered to reduce Dutch greenhouse gas emissions by the end of 2020 by at least 25% in comparison to Dutch emissions in the reference year 1990. The State acknowledges the climate problem and the need to reduce greenhouse gas emissions, as well as the aforementioned 2°C target. The State nevertheless disputes the necessity of reducing Dutch emissions by at least 25% in comparison to 1990 levels before the end of the year 2020. The State believes it is only bound by the emissions restrictions agreed in the EU context. According to the State, being able to select the pathway to be followed in achieving the reductions envisaged for 2030 and 2050, after taking all of the practical options and relevant interests into account, is part of its discretionary power. The State emphasises that the worldwide climate problem can only be addressed on a global scale and that the State is complying with all of its treaty obligations and the international agreements relating thereto.43.

Societal and political debate: Dutch Climate Act

The societal and political debate regarding the greenhouse effect and climate problems has continued outside the context of this case. That debate intensified after the District Court rendered its judgment in the case brought by Urgenda against the State. In this respect, for a better understanding of the procedural documents in cassation that refer to this, it need only be noted that on 12 September 2016, members of the Dutch House of Representatives introduced a legislative proposal for a Climate Act. The bill offers ‘a context for developing policy for the irreversible and gradual reduction of Dutch greenhouse gas emissions for the purpose of mitigating global warming and climate change’.44.The bill was passed by the House of Representatives on 20 December 2018 and by the Senate on 28 May 2019.45.The Climate Act has since been promulgated and with the exception of Article 7, it entered into effect on 1 September 2019.46.

The Climate Act does not contain a standard for greenhouse gas emissions in 2020. Article 2 of this act speaks of ‘a framework for developing policy for the irreversible and gradual reduction of greenhouse gas emissions in the Netherlands to a level that is 95% lower in 2050 than it was in 1990, for the purpose of mitigating global warming and climate change’. The second paragraph of this article continues: ‘In order to achieve this target for 2050, Our Ministers in this area will work to reduce greenhouse gas emissions by 49% in 2030 and to ensure that the generation of electricity is completely CO2-neutral in 2050’. The act provides for the periodic adoption of a climate plan. The first climate period relates to the period from 2021 through 2030 (Article 4(3)).47.

Finally, with regard to the out-of-court debate, it is worth noting that Climate Consultations have been organised in which a large number of stakeholder organisations have participated. Five ‘sector tables’ for electricity, development, industry, agriculture and land use, and mobility are working on a draft climate agreement.48.On 10 July 2018, the main points of a proposal were submitted to the government,49.and the final proposal was submitted on 21 December 2018 − and thus after the date on which the disputed Court of Appeal's judgment was rendered.50.On 28 June 2019 – after the debate in cassation had been closed – the Minister of Economic Affairs and Climate Policy sent a climate agreement to the President of the Senate.51.

The proceedings in the first instance

In the first instance, after amending its claim, and to the extent relevant in cassation, Urgenda requested the District Court to order the State to limit the collective volume of Dutch greenhouse gas emissions such that this volume would be reduced by 40% at the end of the year 2020, or at least by a minimum of 25% in comparison to the volume in the year 1990.52.

In the first instance, Urgenda litigated both on its own behalf and in its role as representative ad litem of the 886 individuals listed in Appendix A to the initiating summons of 20 November 2013.

Urgenda provided, briefly summarized, the following as substantiation for its claim for the reduction order. The greenhouse gas emissions from the Netherlands are contributing to a dangerous change in the climate. The Netherlands’ share of worldwide emissions is excessive, in both absolute and relative terms (per capita of the population). This means that Dutch emissions, for which the State as a sovereign power has systemic responsibility, are unlawful, and in particular violate rules of unwritten law pertaining to proper social conduct towards Urgenda (Article 6:162(2) DCC), as well as Articles 2 and 8 ECHR. Under both national and international law, the State is obliged, in the interests of preventing dangerous climate change, to ensure the reduction of the Dutch emissions level. This duty of care entails that in 2020, the Netherlands must achieve a reduction in greenhouse gas emissions of 25%-40% in comparison to emissions in 1990. A reduction of this magnitude is necessary to have any hope of achieving the 2°C target. This is also the most cost-effective option.53.

What follows is a summary of the defences put forward by the State, to the extent still relevant in cassation. According to the State, Urgenda lacks standing to the extent that it is acting on behalf of current or future generations in countries other than the Netherlands. Apart from this, the reduction order as sought cannot be granted because no unlawful acts have been committed (and there is no real threat that such will be committed) against Urgenda that are attributable to the State. Furthermore, the requirements of Article 3:296 DCC (court order) and of Article 6:162 DCC (unlawful act) have not been met. There is no basis in either national or international law for a duty that legally requires the State to take measures in order to achieve the reduction target as sought. Dutch climate policy does not violate Articles 2 and 8 ECHR. Granting the reduction order being sought would also be contrary to the State's margin of appreciation and the system of the separation of powers.54.

In its judgment of 24 June 2015 (ECLI:NL:RBDHA:2015:7145), the District Court denied the claims for a lack of interest to the extent that Urgenda had instituted these claims on behalf of 886 individual claimants (see paras. 4.10 and 4.109 of the District Court's judgment). To the extent Urgenda is was acting on its own behalf, the District Court held that it did have standing: these are the types of claims that the Dutch legislature wanted to make possible by means of Article 3:305a DCC (para. 4.6 of the District Court's judgment). As, according to its by-laws, Urgenda acts in the interest of a sustainable society that extends beyond the country's borders, it can also base its claims on the assertion that Dutch greenhouse gas emissions may affect persons outside of the country's borders (para. 4.7 of the District Court's judgment). Where Urgenda is acting on behalf of future generations, it is also striving to serve the interest that future generations have in a sustainable society as referred to in its by-laws (para. 4.8 of the District Court's judgment).

To the extent Urgenda is acting on its own behalf, the District Court partially granted the reduction order as sought. The District Court ordered the State to ‘limit the joint volume of Dutch annual greenhouse gas emissions, or have them limited, such that this volume will have been reduced by at least 25% at the end of 2020 compared to the level of the year 1990'. All additional or other claims were denied.55.

At 4.C (paras. 4.11-4.34 of the District Court's judgment), the District Court discussed the current state of the art in climatology and climate policy. According to the District Court, the Dutch reduction target was below the standard considered necessary in the areas of climatology and international climate policy. That standard entails that the prevention of dangerous climate change requires Annex I countries (including the Netherlands) to reduce their greenhouse gas emissions by 25%-40% in 2020 in order to achieve the 2°C target (see para. 4.31(vi) of the District Court's judgment). According to the District Court, the dispute hinges on the question of whether the State is failing to meet its duty of care by applying a reduction target for the year 2020 that is lower than the 25%-40% reduction in comparison to the 1990 standard considered necessary according to climatology experts and international climate policy (para. 4.34 of the District Court's judgment).

At 4.D (paras. 4.35-4.93 of the District Court's judgment), the District Court discussed the question of the legal duty borne by the State. In this respect, the District Court applied the three elements provided for in Article 6:162 DCC, namely: (i) has a subjective right been infringed, or (ii) has the State acted in violation of a statutory obligation or (iii) in violation of rules of unwritten law pertaining to proper social conduct? In paras. 4.36-4.44, the District Court examined whether the State acted in violation of a statutory obligation. The District Court concluded that the State's international law obligations under the UNFCCC, the provisions contained in the Kyoto Protocol and the no-harm principle only entailed obligations to other states. These are not treaty provisions that are ‘binding on all persons’ as referred to in Article 93 of the Dutch Constitution. Urgenda cannot directly rely on those provisions (para. 4.42 of the District Court's judgment). However, when substantively interpreting open standards and terms under national law, including the societal standard of due care, courts may indeed assign a certain ‘reflex effect’ to such international law obligations (para. 4.43 of the District Court's judgment). This also applies to compliance with open standards under European law (para. 4.44 of the District Court's judgment).

The District Court then examined whether any of Urgenda's subjective rights had been violated. The District Court answered this question in the negative. According to the District Court, Urgenda was not entitled to rely on Article 2 or Article 8 ECHR because it could not be considered a direct or an indirect ‘victim’ within the meaning of Article 34 ECHR (para. 4.45 of the District Court's judgment). Articles 2 and 8 ECHR and the ECtHR's substantive interpretation thereof may very well serve as a source of inspiration for the substantive interpretation of open private-law standards (para. 4.46 of the District Court's judgment).

In paras. 4.53-4.82, the District Court examined whether the State was acting in violation of a duty of care ensuing from unwritten law pertaining to proper social conduct. In so doing, the District Court took into account the doctrine of hazardous negligence (the criteria from the Netherlands Supreme Court's judgment in Kelderluik56.; see para. 4.54 of the District Court's judgment), as well as the State's discretionary power (see para. 4.55 of the District Court's judgment) and the targets and principles of international climate law and the law of the European Union, including the principle of a high level of protection, the precautionary principle and the prevention principle (see Article 191(2) TFEU; see paras. 4.56-4.62 of the District Court's judgment). The District Court focused its examination on the question of ‘whether according to objective standards the reduction measures taken by the State to prevent hazardous climate change for humanity and the environment are sufficient, also in view of the State’s discretionary power’ (para. 4.63 District Court’s Judgment).

In that context, the District Court addressed the following, in the order given: (i) the nature and scope of the harm resulting from climate change, (ii) the knowledge and foreseeability of this harm, (iii) the chance that a dangerous climate change will materialise, (iv) the nature of the acts or omissions on the part of the State, (v) the onerousness of the precautionary measures and (vi) the State's discretionary power (paras. 4.63 and 4.64-4.82 of the District Court’s Judgment).

The District Court announced its conclusions in paras. 4.83-4.93. Given the severity of the impact of climate change and the significant chance that a dangerous climate change will occur without mitigating measures, the State has a duty of care to take mitigating measures. Because limiting the concentration of greenhouse gases in the atmosphere to 450 ppm is necessary to prevent dangerous climate change, the State must take measures that will reduce emissions of greenhouse gases so that this limitation can be achieved. It is an established fact that the State's current emissions policy is inadequate (paras. 4.83-4.84 of the District Court’s judgment): the state has opted for a reduction target of less than 20% for 2020. Given the cumulation effect, a postponement as advocated by the State (namely: a less-stringent reduction between 2015 and 2030 and a sharp reduction starting in 2030) will significantly contribute to the risk of dangerous climate change. This postponement is therefore not an adequate and acceptable alternative to the necessary reduction by 25%-40% in 2020 in comparison to 1990 emissions levels – a reduction that has been scientifically proven and acknowledged (para. 4.85 of the District Court’s judgment). The State has not asserted that a reduction of 25%-40% in 2020 would result in a disproportionate burden for the Netherlands or for the State. Given the State's discretionary power, the District Court saw no sufficient grounds to oblige the state to comply with a reduction level in excess of 25% (the lower limit for the aforementioned standard of 25%-40%; see para. 4.86 of the District Court’s judgment).

The District Court then examined whether the unlawful conduct can be attributed to the State, the possibility of harm and the causal link between the acts of the State and that harm, and the relativity requirement (paras. 4.87-4.91 of the District Court’s judgment). The District Court concluded that the State had acted unlawfully towards Urgenda by basing its acts on a reduction target for 2020 of less than 25% in comparison to emissions levels in 1990 (para. 4.93 of the District Court’s judgment).

Finally, the District Court discussed the defence asserting that the order being sought by Urgenda was contrary to the system of the separation of powers. The District Court rejected this defence (paras. 4.94-4.102 of the District Court's judgment).57.

The proceedings on appeal

The State filed an appeal against the District Court's judgment with The Hague Court of Appeal. With 29 grounds for appeal, the full scope of the dispute was presented to the Court of Appeal.58.

Urgenda, litigating on its own behalf,59.instituted a cross-appeal, asserting a single ground for appeal. This ground was aimed at the District Court's opinion that in light of Article 34 ECHR, Urgenda could not rely on Articles 2 and 8 ECHR in these proceedings. Urgenda did not object to the District Court's refusal to issue a reduction order that extends beyond the 25% reduction in 2020.60.The appeal was not directed against the rejection of its other claims.

On balance, the only outstanding question on appeal was whether the State was obliged to reduce, or to ensure the reduction of, greenhouse gas emissions at the end of 2020 by 25% in comparison to Dutch emissions levels in 1990. Like the District Court, the Court of Appeal answered this question in the affirmative.

In its judgment of 9 October 2018 (ECLI:NL:GHDHA:2018:2591), the Court of Appeal sustained Urgenda's ground in the cross-appeal. The District Court failed to appreciate that Article 34 ECHR only concerns access to the European Court of Human Rights (ECtHR) (para. 35). Assuming that individuals who fall under the State’s jurisdiction may invoke Articles 2 and 8 ECHR, which have direct effect, before a Dutch court, Urgenda is entitled to do so on their behalf under Article 3:305a DCC. The Court of Appeal rejected the State’s grounds in the principal appeal (para. 76).61.The Court of Appeal then affirmed the District Court's judgment and declared its own judgment to be immediately enforceable regardless of any appeal.62.

Briefly summarised, the Court of Appeal held as follows. There is no dispute as to Urgenda's standing to pursue its claim to the extent that it is representing the current generation of Dutch residents. It is without a doubt plausible that the current generation of Dutch residents will have to deal with the adverse effects of climate change in their lifetime if global emissions of greenhouse gases are not adequately reduced. This means that the question of whether Urgenda has standing to pursue its claims on behalf of future generations of Dutch residents and current and future generations of foreigners need not be addressed (para. 37). Urgenda has a sufficient interest in its claim, as there is a real threat of dangerous climate change (para. 38).

If the State knows that there is a real and immediate risk, it has a positive duty pursuant to Articles 2 and 8 ECHR to take preventive measures (para. 43). The State has a wide margin of appreciation when it comes to choosing the measures to be taken (para. 42). Based on the facts and circumstances proven during the proceedings (para. 44), it is appropriate to speak of a real threat of dangerous climate change, resulting in the serious risk that the current generation of Dutch residents will be confronted with loss of life and/or disruption of family life. Pursuant to the provisions of Articles 2 and 8 ECHR, the State is obliged to offer protection against this real threat (para. 45).

With regard to the unlawful acts that were asserted, the Court of Appeal's opinion can be summarised as follows (paras. 46-53):

- The parties agree that global greenhouse gas emissions must be brought to a halt in 2100. The parties do not disagree on the reductions that will be necessary in the interim, those being emissions reductions of 80%-95% in 2050 and 49% in 2030. What must be examined is whether the State has acted unlawfully in respect of Urgenda by failing to reduce, or failing to ensure the reduction of, greenhouse gas emissions by at least 25% by the end of 2020 despite the aforementioned real threat (para. 46).

- A substantial effort must be made in order to achieve a reduction of 49% in 2030. It is also an established fact that it is desirable to start the reduction efforts at the earliest stage possible in order to limit the total emissions in this period. If the equal distribution constituting the State's premise for the reduction target of 49% in 2030 were extrapolated to the present, the result would be a reduction target of 28% before the end of the year 2020 (para. 47).

- In both AR4 and AR5, the IPCC also assumes that a concentration level of 450 ppm may not be exceeded if the 2ºC target is to be achieved. According to AR4, for that level to be achieved, the total emissions by Annex I countries (of which the Netherlands is one) must be 25% to 40% lower in 2020 than in 1990 (para. 48). AR5 gives no reason to assume that the reduction scenario from AR4 has become outdated. The Court of Appeal therefore assumed that an emissions reduction of 25%-40% must be achieved in 2020 if the 2ºC target is to be achieved (para. 49).

- Incidentally, even in the 450 ppm scenario, there will still be a real risk that the 2ºC target will not be met, even despite the fact that it has since been acknowledged that, to be safe, the temperature rise would have to be much closer to 1.5ºC than to 2ºC. Therefore, neither the 450 ppm scenario nor the reduction target of 25%-40% in 2020 based on that scenario is overly pessimistic (para. 50).

- The State has known about the reduction target of 25%-40% for a long time. This reduction target has been referenced at climate conferences since AR4 was published in 2007.63.That may not have established a directly binding legal standard, but it does confirm that a reduction of at least 25%-40% in 2020 is required to prevent dangerous climate change (para. 51).

- Lastly, the Court of Appeal held that it is relevant that until 2011, the State's reduction target for 2020 was 30% because the State was convinced that a reduction of less than 25%-40% in 2020 would not be credible to keep the 2ºC target within reach. No scientific substantiation was provided for the adjustment of the Netherlands’ reduction target for 2020; in particular, the State failed to substantiate why a reduction of only 20% per 2020 should now be considered credible in an EU context (para. 52). The Court of Appeal is of the opinion that a reduction obligation of at least 25% by the end of 2020, as ordered by the District Court, is in line with the State’s duty of care (para. 53).

- In the findings that follow, the Court of Appeal discussed the State's defences, including the argument that the ETS system precludes farther-reaching reduction measures (para. 54) and State's reliance on the waterbed effect and carbon leakage (paras. 55-58). The fact that climate change is a worldwide problem that the State cannot solve on its own does not relieve the State of its obligation to take measures in its territory, within its capabilities, which, in concert with the efforts of other states, provide protection from the hazards of dangerous climate change (para. 62). According to the Court of Appeal, the fact that there is no complete scientific certainty regarding the effectiveness of the reduction order does not entitle the State to refrain from taking further measures (para. 63).

Finally, the Court of Appeal rejected the State's reliance on the system of the separation of powers. The Court of Appeal held that measures were called for because the State was violating human rights, and that the reduction order imposed on the State allowed it sufficient room to choose how it would comply with that order (para. 67). The District Court had not issued a prohibited order to enact legislation, either (para. 68). The Court of Appeal emphasised that it was obliged to apply treaty provisions with direct effect – such as Articles 2 and 8 ECHR – if the Netherlands is a party to the treaty in question (para. 69). The Court of Appeal held that the State was failing to fulfil its duty of care pursuant to Articles 2 and 8 ECHR by not reducing emissions by at least 25% by the end of 2020. By so doing, the State is acting unlawfully. The Court of Appeal therefore declined to address the State's grounds regarding the doctrine of hazardous negligence (para. 76).

The proceedings in cassation

The State instituted its appeal in cassation in good time, and seeks the reversal of the Court of Appeal's judgment and such further relief as the Supreme Court deems appropriate.64.

In cassation, Urgenda submitted a Defence, which it concluded with a motion to deny the request for cassation.

On 24 May 2019, the parties had their attorneys argue orally their positions based on the Written Arguments they submitted. A further Written Explanation was provided by the State on that same day. Urgenda declined to provide a further Written Explanation on that day.

On 21 June 2019, the State submitted a Reply and Urgenda a Rejoinder, after which the parties requested the Supreme Court to render judgment.65.

For the benefit of non-Dutch readers, we note that new findings of fact are not given in proceedings for cassation: the court in cassation is bound by the Court of Appeal's findings of fact. The Supreme Court limits its examination to the grounds on which the appeal in cassation is based. Grounds are the reasons a litigant asserts for the reversal of the disputed judgment. A judgment can be reversed if certain procedural requirements have not been met or if the law has been violated – although the latter does not apply to the laws of foreign states. The factual basis for the grounds is limited to the disputed judgment and the procedural documents.66.

Ground for the reduction order; layout of this chapter

The duty of care accepted by the District Court and the Court of Appeal – the obligation to reduce greenhouse gas emissions from Dutch territory by 25% as of the end of 2020 in comparison to 1990 – is not part of any written national or international law as such. The District Court derived this duty of care from the open standard of Article 6:162(2) DCC. The Court of Appeal identified a treaty-law basis for this duty of care in the open standards of Articles 2 and 8 ECHR. To that extent, the reasoning underlying the two judgments differs. However, the specific, substantive interpretation of the duty of care – the factual substantiation for the reduction order based on insights drawn from climatology, the targets of international climate policy and the standards and principles of international law – is largely the same in the reasoning of both the District Court and Court of Appeal.67.

To promote a thorough understanding of the reasons offered by the District Court and the Court of Appeal, this chapter discusses introductory considerations regarding tort law, including the doctrine of hazardous negligence as applied by the District Court, and Articles 2 and 8 ECHR as applied by the Court of Appeal.

The requirements of standing for a class action are discussed first (para. 2.3 et seq.), followed by a segue into the meaning of the causality requirement (para. 2.10 et seq.). We then discuss the judicial review of lawfulness under Dutch law and the general standard of care (para. 2.14 et seq.), devoting special attention to the doctrine of hazardous negligence (see para. 2.20 et seq.). The carry-over effect of international law on Dutch law (in the context of the judicial review of lawfulness) is then discussed in para. 2.26 et seq.

After that, attention is turned to the European Convention on Human Rights (ECHR). After several introductory remarks about the scope of protection (see para. 2.34 et seq.), attention will be devoted to ECtHR case law on positive obligations pursuant to Articles 2 and 8 ECHR (para. 2.41 et seq.). Afterwards, in para. 2.50 et seq., we will examine whether the Court of Appeal was entitled to base its reduction order on those articles. To that end, we discuss four main lines of ECtHR case law (para. 2.53 et seq.). In Chapter 3, we discuss the State's complaints regarding the human rights-law aspects of the order. The technical climatological aspects of the order will be discussed in Chapter 4.

Protection of general interests in a class action

Pursuant to Article 3:305a DCC, a legal entity like Urgenda may institute a legal claim to protect the ‘similar interests’ of other parties to the extent it promotes such interests pursuant to its by-laws (para. 1). The legal entity may be held to lack standing if it has not made sufficient efforts to achieve the object of the claim through negotiations with the defendant, or if the interests of the persons on whose behalf the claim was instituted are not sufficiently safeguarded by that claim (para. 2). The legal claim cannot be intended to obtain an award of monetary compensation (para. 3).68.

Article 3:305a DCC offers a basis for both ‘group actions’ and ‘general interest actions’. Where group actions are involved, the collective interests of a specific or specifiable number of individuals are represented. General interest actions involve a legal entity representing general interests that cannot be individualised because they accrue to a much larger, and thus diffuse and unspecific group of persons.69.

According to the history of this statutory provision, ideological interests can also be represented in a class action. Societal divisiveness about the value that must be attributed to such interests or the manner in which those interests must be weighed against other, conflicting interests do not deprive a claimant of standing in a class action in the Netherlands.70.Nor does the fact that ‘diffuse’ interests are involved, in the sense that addressing the harmful effect of a violation of the right being invoked on individuals is difficult, form an impediment.71.Building on this, the Supreme Court has held that the fact that a substantial portion of the individuals whose interests a class action is intended to protect disagree with the objective of the claim also does not preclude a claim pursuant to Article 3:305a DCC. According to the Supreme Court, the decisive factor in a given case is whether it involves ‘similar interests’ within the meaning of Article 3:305a(1) DCC. That requirement is met if the interests in question lend themselves to consolidation such that the effective and efficient legal protection of the stakeholders can be advanced.72.

In accordance with the foregoing, the parliamentary history and case law accept that a class action to protect the living environment can be instituted without this requiring an identifiable group of individuals in need of protection.73.An argument that also applies in such cases is that efficient and effective legal protection can be advanced if, rather than litigating the same issue against the government separately, individuals opt instead to debate the issue (exchange arguments) on a collective level. As stated, the District Court did not address the issue of standing to the extent Urgenda was acting as the representative ad litem for the 886 individual claimants in the first instance.74.The District Court held that Urgenda had standing to the extent it was acting on its own behalf, including to the extent it was representing the interests of persons outside of Dutch territory and future generations.75.The Court of Appeal did not address the State's grounds regarding that issue, because according to the Court of Appeal, there is no dispute that Urgenda has standing to the extent it is acting on behalf of the current generation of Dutch residents against greenhouse gas emissions in Dutch territory.76.

Requirement of a sufficient interest in cases seeking orders or injunctions

As an extension of the issue of standing just discussed – the question of whether environmental interests are eligible for protection based on Article 3:305a DCC – there is the question of whether Urgenda has a sufficient interest, as meant in Article 3:303 DCC, in the court order it is seeking. The Court of Appeal answered that question in the affirmative in para. 38. None of the complaints in cassation are directed against that opinion.77.The requirement of a sufficient interest also plays an auxiliary role in the complaints on the effect of the reduction order.78.

Article 3:296 DCC allows a court to order a party to perform its legal obligation to another party if that other party institutes a claim to that effect. Granting a claim for an order or injunction that is intended to prevent a future violation of a standard does not require that all the requirements for liability pursuant to an unlawful act, as laid down in Article 6:162 DCC (unlawfulness, attributability, harm, causal connection and relativity) must be met. What is required is that (i) the defendant is under a legal obligation to the claimant and (ii) the claimant has a sufficient interest in preventing the imminent breach of that obligation. The first follows from Article 3:296 DCC (‘he who is obliged to another...’). The second follows from Article 3:303 DCC (‘A person has no right of action where he lacks sufficient interest.’).

In the context of a claim for an injunction pursuant to an unlawful act, the Supreme Court has put it in the following terms: there must be a ‘specific interest’ in the injunction, in the sense that there is a ‘specific and real threat’ that the prohibited actions will be taken.79.

Requirement of causality in cases seeking orders or injunctions

The foregoing implies that the granting of an order or injunction pursuant to Article 3:296 DCC in connection with Article 6:162 DCC requires no demonstrable or imminent harm, nor any connection with an unlawful act that has already been committed. It does, however, require an imminent impairment of interests as a result of the feared unlawful act.80.This follows on the one hand from the aforementioned requirement of a sufficient interest as laid down in Article 3:303 DCC and, on the other, from the unlawfulness requirement as laid down in Article 6:162 DCC. ‘Unlawfulness’ is a relative term, of course, in the sense that the violation of a standard is only unlawful in respect of persons whose interests are protected by the standard that has been violated (Article 6:162(1) DCC; cf. also Article 3:296(1) DCC and Article 6:163 DCC).81.Furthermore, many ‘unlawful act standards’ – including the safety standard applied by the District Court to determine whether there was an issue of hazardous negligence and the standard applied by the Court of Appeal relating to the government's ‘positive obligations’ in respect of situations which are hazardous to the living environment – are essentially based on a weighing of interests. The court never proceeds to such a weighing of interest if the claimant does not qualify as an ‘interested party’; in other words, a potential ‘victim’ of the violation of the law.82.

The literature also refers to the difficulties that the foregoing can cause in the context of climate change. Climate change is a global problem that is attributable to many causes. The reduction of greenhouse gas emissions by one country will not eradicate the worldwide danger of climate change. When it comes to small countries like the Netherlands, reductions have only a limited effect on global emissions. This gives rise to the question of whether Urgenda has a sufficient interest in the reduction order it seeks. More specifically, there is a question of whether the imminent impairment of interests resulting from climate change may be effectively counteracted by obliging just the Netherlands to a certain degree or certain speed of reduction.83.

All things considered, the issue is a causality problem that is part and parcel of all cases of environmental harm.84.Harm to the living environment usually occurs gradually, due to a multitude of factors, as a consequence of pollution that does not stop at a country's borders.85.This does not seem to be an insurmountable obstacle to holding polluters liable for any resulting harm. In the Kalimijnen judgment, which concerned the harm caused by the discharge of salt into a river, the Supreme Court accepted the possibility that each polluter would be held liable for a percentage of the harm that corresponded to its share in the pollution.86.This 'linear' approach – to be distinguished from ‘joint and several’ liability for all harm, is also recognised in international environmental law.87.The literature also refers to Article 47(1) of the Articles on Responsibility of States for Intentionally Wrongful Acts as established by the International Law Commission: ‘Where several States are responsible for the same internationally wrongful act, the responsibility of each State may be invoked in relation to that act.’88.

By analogy, it might also be assumed that a claimant has a sufficient interest in being granted the order or injunction it is seeking if the order or injunction could contribute to preventing the asserted imminent impairment of interests.89.An illustrative example, and one that is also cited by Urgenda,90.is the US Supreme Court's decision in the case of Massachusetts v. Environmental Protection Agency. Very briefly put, that case concerned the question of whether the US Environmental Protection Agency (EPA) was bound to regulate the emission of CO2 as an air pollutant. The US Supreme Court answered that question in the affirmative, holding inter alia:

‘While it may be true that regulating motor-vehicle emissions will not by itself reverse global warming, it by no means follows that we lack jurisdiction to decide whether EPA has a duty to take steps to slow or reduce it. … A reduction in domestic emissions would slow the pace of global emissions increases, no matter what happens elsewhere.’91.

Violation of human rights as an unlawful act

As stated, a defendant must have a legal duty to the claimant in order for an order or injunction to be granted. Such a legal duty may be based on inter alia Article 6:162(2) DCC. That provision defines an 'unlawful act' as: (i) the violation of a right, (ii) an act or omission breaching a duty imposed by law and (iii) an act or omission breaching a rule of unwritten law pertaining to proper social conduct.

The impairment of human rights that are protected by the constitution and/or treaty law may fall within the scope of the first or second category of unlawfulness referred to in the previous paragraph. Human rights may also influence the substantive interpretation of an unwritten rule of law (the third category).92.The District Court chose the latter route in this case, by attributing a 'reflex effect' to (inter alia) Articles 2 and 8 ECHR93.in the context of reviewing the unwritten law. The disputed judgment does not indicate with certainty whether the Court of Appeal was applying Articles 2 and 8 ECHR directly or indirectly, by way of Article 6:162(2) DCC.94.Regardless, when specifically interpreting the duty of care derived from Articles 2 and 8 ECHR, the Court of Appeal relied not only on ECtHR case law, but also on treaties, principles of international climate law, and non-binding international climate policy instruments, such as the various COP decisions cited by the Court of Appeal. The question of the extent to which such international legal sources have a carry-over effect on national legal order (directly via Articles 2 and 8 ECHR, or indirectly via Article 6:162(2) DCC) is discussed in paras. 2.26 et seq. below.

For the sake of completeness, we note that the constitutional right to environmental protection anchored in Article 21 of the Constitution ('It shall be the concern of the authorities to keep the country habitable and to protect and improve the environment') must be interpreted as an 'instructional standard' aimed at the government.95.It is against this backdrop that this provision has played only a subordinated role in these proceedings.96.

Violation of the standards of due care as an unlawful act

The third category of unlawful act referred to in Article 6:162(2) DCC which the District Court applied can be traced back to the Lindenbaum/Cohen judgment from 1919.97.Since that judgment, it has generally been accepted that engagement in an act or omission breaching a rule of unwritten law pertaining to proper social conduct also constitutes an unlawful act.

Characteristic for this category of unlawful act is its contextual nature: what the unwritten law entails in a given set of circumstances must be assessed on a case-by-case basis. This comes down to a weighing of interests.98.In the Kalimijnen judgment referred to above, which regarded environmental pollution resulting from discharges of salt into a river, the Supreme Court held that when answering the question of whether the discharges of salt were contrary to the unwritten law of generally accepted standards and thus constituted an unlawful act against the users of the river downstream, account had to be taken 'on the one hand, of the nature and weight of the interests served by the discharges and, on the other, the interests served by the downstream use'. Building on this, the Supreme Court held 'that in weighing these opposing interests, special weight must be assigned to the interests of the downstream user to the extent that said person might, in principle, expect the river not to be excessively polluted by major discharges'.99.

A standard that depends on the circumstances of the case can be challenged on the ground that it offers insufficient legal certainty. The literature thus also shows that, when possible, the courts must base specific interpretations of standards of care on objective assumptions.100.The following are examples of what might serve as objective assumptions: non-binding guidelines and codes of conduct (both of which are 'soft law'), as well as treaty provisions and principles of international law which do not have direct effect. We revisit this topic in para. 2.30, et seq.

Points of view on unlawful hazardous negligence (Kelderluik factors)

An assessment framework has been developed in case law for the review of due care in cases involving hazardous negligence. These are situations in which the perpetrator has caused a hazard to persons or property to arise and/or has allowed such hazard to continue to exist. The societal standard of due care requires persons to refrain from exposing others to a hazard greater than what is reasonably responsible in the given circumstances. More specifically, this means that depending on the circumstances, adequate precautionary measures must be taken to eliminate the hazard or at least to reduce it to socially acceptable proportions.101.

Most cases of hazardous negligence regard a hazard created by the perpetrator himself. The doctrine also applies to persons who have put another person in jeopardy through negligence. In particular, this concerns persons who owe a special duty of care to potential victims, such as managers of buildings and building sites.102.However, the government's liability as a supervisory authority in respect of hazardous activities perpetrated by others is also linked to the doctrine of hazardous negligence.103.

In the Kelderluik (‘Cellar hatch’) judgment, the Supreme Court formulated points of view on the unlawfulness assessment in cases involving hazardous negligence. These points of view concern (i) the probability that potential victims would not exercise the required attention and due care, (ii) the chance that accidents would ensue as a result, (iii) the seriousness of the possible consequences, and (iv) the onerousness of precautionary measures.104.These ‘Kelderluik factors’ were repeated in later case law, and supplemented with additional points of view, such as (v) the ‘normality’ of precautionary measures and (vi) the nature of the conduct.105.

The Kelderluik factors focus on hazardous negligence situations. Although these do not constitute a framework for applying societal standards of due care in general,106.these factors are still applied even in cases which do not involve hazardous negligence (analogously, supplemented with additional points of view, if necessary).107.In this respect, it is relevant that the Kelderluik factors are in line with basic notions about handling risks. They are grounded in legal and economic principles and are also accepted, in similar phrasing, in other legal systems. One example is the 'Learned Hand' formula108.in Anglo-American legal systems.109.The Principles of European Tort Law and the Oslo Principles on Global Climate Obligations contain comparable assessment frameworks.110.The Kelderluik factors show similarities to the viewpoints which the ECtHR maintains in its case law on positive obligations in environmentally hazardous situations (to be discussed below).111.

Hazardous negligence as ground for obligations in connection with the climate?

In this case, as explained, the District Court applied the Kelderluik factors, supplemented by other viewpoints, such as the discretionary power to which the government is entitled. Some authors have criticised the application of the doctrine of hazardous negligence. In their opinion, this doctrine is intended for simple accident situations and is not suitable for assessing government policy in issues that are as complicated as climate change.112.Other authors believe that the doctrine of hazardous negligence is the perfect framework for addressing the dangers of climate change. In this regard, they refer to the broad applicability of the Kelderluik factors as a general framework for dealing with risks.113.

In various commentaries on the contested judgment, the application of treaty law binding on all persons (Articles 2 and 8 ECHR) is deemed a more legitimate approach from the constitutional perspective than assigning ‘reflex effect’ to non-binding treaty provisions within the context of Article 6:162(2) DCC.114.It can be added to this that human rights appear to be increasingly internationally acknowledged as a possible basis for ‘climate obligations’ of the government (see section 2.79 et seq. below). Nevertheless, the human rights approach of the Court of Appeal has been criticised (see section 2.51 et seq. below).

Direct effect and/or reflex effect of international law

Both in the Court of Appeal’s human rights approach and in the District Court’s reasoning based on Article 6:162 DCC, standards and principles of international law and non-binding instruments of international climate policy play an important role in the substantive interpretation of the State’s obligations in relation to the dangers of climate change.

For some time now, the Dutch Constitution has contained provisions that make it possible for the court to also incorporate treaty law in its judgment, in addition to the applicable laws. Article 93 of the Dutch Constitution stipulates that provisions of treaties and resolutions by international organisations that may be binding on all persons by virtue of their contents will become binding after they have been published. Article 94 of the Dutch Constitution stipulates that statutory regulations in force within the Kingdom do not apply if such application is in conflict with provisions of treaties or of resolutions by international institutions that are binding on all persons. This constitution provision has made it possible for the court, when assessing a submitted claim, to dis-apply a statutory regulation on the grounds of it conflicting with a provision of a treaty that is binding on all persons.115.

The concept of ‘provisions of treaties (...) that may be binding on all persons by virtue of their contents’ is interpreted by the Supreme Court as follows:

'The question as to what extent a provision of a treaty has direct effect within the meaning of Articles 93 and 94 of the Dutch Constitution must be answered by means of its interpretation. This interpretation should be based on the standards set out in Articles 31-33 of the Vienna Convention on the Law of Treaties of 23 May 1969 (Bulletin of Treaties, 1972, 51, and 1985, 79). (...) If it does not follow from either the text or the treaty's history that the provision of the treaty was not meant to have direct effect, the content of that provision is decisive. The question is whether it is unconditional and sufficiently precise to be applied as a positive right in the national legal order without reservation (see Supreme Court 1 April 2011, ECLI:NL:HR:2011:BP3044, NJ 2011/354 (…)). If the result to be achieved under a provision of a treaty in national law is unconditional and sufficiently precise, the mere fact that the legislator or the government is allowed freedom of choice or policy as to the measures to be taken to achieve that result does not preclude the provision from having direct effect. Whether that effect exists depends on whether the provision can function as a positive right in the context in which it is invoked. Contrary to what the State argues, the mere existence of freedom of choice or policy does not mean that there can be no direct effect. (Cf. Supreme Court 09 April 2010, ECLI:NL:HR:2010:BC4959, NJ 2010/388 (SGP))'.116.

Advocate General P. Vlas made the following comments on this standard:117.

'What is new is that the Supreme Court has considered that the direct effect of a treaty provision depends on the question of whether “the provision can function as a positive right in the context in which it is invoked'. The Supreme Court therefore seems to accept a contextual, or relative, approach to the direct effect of treaty provisions. As a result, depending on the context in which it is invoked, a treaty provision will have direct effect in one case and not in another, and the assessment of the direct effect of a treaty provision and the assessment of its compatibility with that provision will become more closely intertwined.’

Treaty provisions that are not ‘binding on all persons’ within the meaning of Articles 93 and 94 of the Dutch Constitution can only have an indirect impact on the finding of unlawfulness. First of all, the interpretation of rules of national law is ‘treaty-based’ where possible, in accordance with the principle of international law that States are presumed to want to comply with their treaty obligations. Secondly, in implementing open standards, the national court will take international law into account as much as possible (irrespective of whether or not it has direct effect). This is the concept of reflex effect. It should be noted that it is not always possible to make a clear distinction between the two figures.118.

Soft law as a source of international law

The distinction between direct effect, interpretation in accordance with the treaty and reflex effect has become more vague with the rise of ‘soft law’ within the context of international law. This refers to a wide variety of non-binding international instruments, such as guidelines, action plans, conference statements and non-binding resolutions of international organisations. Although these instruments are not legally binding in themselves, significance is increasingly attributed to them in the implementation of generally formulated obligations under international law119.and, by extension, in the implementation of open standards in national law.120.The ECtHR uses this technique as well,121.in the context of the common ground method to be discussed below. Moreover, it has been argued in the literature that it is not so much the legal status of the instrument that should be decisive for the classification as hard law or soft law, but rather the actual substance of the rule laid down therein, i.e. whether or not that rule is suitable for application as a binding law.122.This approach is somewhat comparable to the ‘contextual’ criterion from the Smoking Ban judgment discussed in para. 2.28.

History shows that soft law not seldom acts as a trailblazer for hard law: initially non-binding action plans and declarations of intent can later result in enforceable obligations under international law.123.N.J. Schrijver refers to this process as ‘crystallization’.124.Climate change is cited as an example of a field of law in which soft law has developed into hard law over the years, although it should be noted that by no means all of the objectives that the international community has set for itself in this respect have ultimately been enshrined in binding treaties.125.But this does not alter the fact that soft law can also play an important role in this subject. For instance, the authors of the Oslo Principles on Global Climate Obligations argue the following:

'The repeated pledges by world leaders, in and outside the COP framework, and the urgent need to come to grips with the looming threats advocated by these leaders may in themselves not amount to legal obligations, but they are not meaningless either. Taken together with other legal bases, they help to crystallise enforceable obligations on countries.'126.

Fleuren concludes that this has put the concept of ‘direct effect’ into perspective. He endorses this outcome and, to that extent, the judgments of the District Court and the Court of Appeal.127.Schrijver, Loth and Van Gestel are also positive about the way in which the District Court has linked national and international law in this case.128.Other authors are critical on this point. Briefly put, their opinion is that the limits of the judiciary's duty in forming law are exceeded when reflex effect is assigned to non-directly binding treaty provisions and (all the more) by assigning reflex effect to non-binding international instruments.129.

Protection of human rights under the ECHR

Article 1 ECHR provides that the Contracting Parties shall secure to everyone within their jurisdiction the rights and freedoms defined in Section I of the Convention. This obligation on States to respect human rights determines in many respects the scope of the legal protection provided by the ECHR. First of all, this shows that human rights apply primarily in the (vertical) relationship between government and citizens (see section 2.35 below). Secondly, this shows that the legal protection offered by the ECHR is, in principle, territorial (see section 2.36). Thirdly, it follows from Article 1 ECHR that human rights must be protected effectively and actively (see sections 2.37 and 2.38) and that such protection must be provided primarily at national level (see section 2.39). Finally, it is important that the ECHR requires a minimum level of protection and therefore does not oppose additional protection at national level (see section 2.40 below).

Individual legal protection Human rights are originally intended as an instrument to protect individuals from government interference. Although national law also attributes ‘horizontal effect’ to human rights,130.the legal protection offered by the ECHR is still dominated by ‘a search for a fair balance between the demands of the general interest of the community and the requirements of the protection of the individual’s fundamental rights’.131.This emphasis on individual legal protection is also expressed in Article 34 ECHR, which only grants a right of complaint to individuals and organisations who themselves are a victim of a human rights violation.132.An ‘actio popularis’ to promote human rights in general is therefore, in principle, not possible under the ECHR.133.However, this limitation is not absolute: as will be shown below, the ECHR also offers ‘general protection to society’ in certain situations (see section 2.59 below) and the ECtHR has stretched the victim requirement in appropriate cases in order to ensure effective legal protection (see sections 2.58 and 2.62 below).

Territorial legal protection According to the ECtHR, the concept of jurisdiction in Article 1 ECHR must principally be interpreted in a territorial sense. The point is whether the victim is on the territory of the Contracting State. Exceptions to this territoriality principle have also been accepted by the ECtHR in the context of extraterritorial activities of a State, such as violations of human rights by diplomats or military personnel in respect of victims outside the territory of the State.134.Whether cross-border environmental damage also falls within the scope of this exception has not yet been decided in the ECtHR case law. The existing ECtHR case law does seem to offer bases for this,135.as does the case law of other human rights courts.136.

Principle of effective interpretation According to established case law, the provisions of the ECHR must be interpreted and applied in such a way that the rights guaranteed therein are practical and effective. This follows from ‘the object and purpose of the Convention as an instrument for the protection of individual human beings’,137.according to the ECtHR. This is in line with the interpretation standard of Article 31(1) of the Vienna Convention on the Law of Treaties.138.Application of the principle of effective interpretation referred to here generally leads to an extensive interpretation of the ECHR. The stretching of the ‘victim’ requirement is an example of this.139.

Positive obligations The positive obligations from Articles 2 and 8 ECHR to be discussed below can also be regarded as an application of the principle of effective interpretation. The idea is that effective protection of human rights not only requires the government to refrain from violating these rights, but under certain circumstances also requires it to make an active effort to prevent human rights from being compromised by third parties or external factors (such as natural disasters).140.This means that a violation of positive obligations often involves multiple causality, in the sense that the human rights violation is caused by a combination of factors, including negligence on the part of the government.141.In this respect, the positive obligations do not require an absolute guarantee against human rights violations (see section 2.53 below in this context).

Principle of subsidiarity The ECtHR deduces from Article 1 ECHR that the protection of ECHR rights must be offered primarily by the national authorities, including national courts. The ECtHR has assigned itself a subsidiary role in this respect.142.The principle of subsidiarity referred to here also forms the backdrop for the margin of appreciation doctrine to be discussed below, which the ECtHR uses to grant national authorities a margin of appreciation in appropriate cases.143.While this may evoke associations with the constitutional principle of the separation of powers, the principle of subsidiarity is not dominated by judicial restraint.144.On the contrary: the ECtHR requires national courts to assess human rights claims ‘with particular rigour and care’, ‘as a corollary of the principle of subsidiarity’.145.The margin of appreciation doctrine therefore cannot serve – or at most only serve by analogy – as a basis for a cautious approach on the part of the national court in human rights issues (see section 2.69 below).

Minimum protection Article 53 ECHR provides that the Convention is without prejudice to the protection of human rights under national laws and/or treaties. In other words, the ECHR requires a minimum level of protection and leaves Contracting Parties free to provide additional protection. Comparative law research from 2014 has shown that national courts generally seek alignment with the minimum level of protection required by the ECtHR.146.As far as the assessment of laws in a formal sense147.on the basis of the ECHR is concerned, the Dutch court is not allowed to offer additional protection:

‘Pursuant to Article 93 of the Dutch Constitution, the Dutch court must apply the provisions of the ECHR that are binding on all persons. This means that it is also obliged to interpret those provisions, it being understood, however, that the division of tasks between the national court and the ECtHR means that the national court, in its interpretation of the provisions of the ECHR, must comply with the established case law of the ECtHR. It is true that Article 53 ECHR leaves the Contracting States free to offer more far-reaching protection than ensues from the provisions of the ECHR, but Articles 94 and 120 of the Dutch Constitution imply that the Dutch court may only dis-apply enacted legislation or provisions thereof if that legislation is incompatible with provisions of treaties and resolutions of international organisations that are binding on all persons. In view of what has just been considered, however, such incompatibility cannot be assumed on the basis of an interpretation by the national – Dutch – court of the concept of property in Article 1 FP that deviates from the established case law of the ECtHR with regard to that treaty provision.'148.

Positive obligations from Article 2 ECHR

The following is a brief inventory of the ECtHR case law relevant to this case concerning positive obligations from Articles 2 and 8 ECHR. For the sake of brevity, reference is made to the case law reports drawn up by the Directorate of the Jurisconsult of the ECtHR, in which the relevant case law is presented more extensively, also indicating the corresponding sources.149.

Article 2 ECHR protects the right to life. This Article not only prohibits the intentional deprivation of life, but also stipulates the positive obligation to take measures to protect the right to life.150.Article 2 ECHR also applies to life-threatening situations. The positive obligation to protect against the danger to life is twofold. It covers on the one hand the obligation to provide an adequate legal framework (see the first sentence of Article 2 ECHR) and, on the other hand, the obligation to take actual precautionary measures. This positive obligation applies to inter alia dangerous industrial activities, regardless of whether these have been carried out by public or private operators, and in the context of natural disasters. According to established case law, Article 2 ECHR does not offer an absolute guarantee against every conceivable danger.151.

The ECtHR has developed an assessment framework for cases where individuals are threatened by violent behaviour by others, such as dangerous criminals and psychiatric patients. In such cases, there is a positive obligation under Article 2 ECHR to protect the person or persons at risk. According to established case law, this obligation, also known as the Osman obligation,152.must not impose an 'impossible or disproportionate burden' on the national authorities. That is why the ECtHR attaches to this the condition that the authorities 'knew or ought to have known at the time of the existence of a real and immediate risk to the life of an identified individual or individuals from the criminal acts of a third party and that they failed to take measures within the scope of their powers which, judged reasonably, might have been expected to avoid that risk'. The ECtHR also accepted the Osman obligation in cases where the potential victims could not be identified in advance, for example in the case of random victims of violent persons. In this specific context, according to the ECtHR, Article 2 ECHR offers general protection to society.153.

With a focus on activities that are dangerous, or dangerous to the environment, Article 2 ECHR primarily requires the Contracting States of the Treaty to provide for 'a legislative and administrative framework designed to provide effective deterrence against threats to the right to life'.154.As regards the choice of measures to reduce the danger, the authorities of the Contracting States have been afforded a 'margin of appreciation'. Again, the measures should not create an 'impossible or disproportionate burden' for the national authorities. This is even more true in 'difficult social and technical spheres' in which the ECtHR awards a 'wide margin of appreciation' to Contracting States. In the assessment of measures taken by a Contracting States, significance is attributed to, among other things, 'domestic legality', the 'domestic decision-making process' and the underlying facts, the 'complexity of the issue', 'the origin of the threat', and the extent to which the danger is susceptible to 'mitigation'. When undertaking or authorising dangerous activities, the State in question must ensure that risks are limited to 'a reasonable minimum'.155.

The ECtHR has on several occasions accepted a violation of Article 2 ECHR with regard to a natural or environmental disaster. This concerned, for instance, a gas explosion at a rubbish tip,156.a mudslide caused by natural disaster,157.a flood caused by poor water management,158.and exposure to asbestos at a shipyard.159.

Positive obligations from Article 8 ECHR

Article 8 ECHR protects the right to respect for private and family life. It offers comprehensive protection, which in part builds on from Article 2 ECHR. Where Article 2 ECHR does not apply (e.g. in situations that affect the quality of life but are not life-threatening), it is sometimes possible to fall back on Article 8 ECHR.160.

Article 8 ECHR also applies to environmental issues, among other things. Although the ECHR does not involve the right to protection of the living environment in general, where environmental pollution has direct consequences for the right to respect for private and family life (in particular the home) and is sufficiently serious. Article 8 ECHR can be applied without requiring that the health of the complainant be threatened. Socially acceptable forms of nuisance (such as 'environmental hazards inherent to life in every modern city') are not within the scope of protection offered by Article 8 ECHR.161.

Article 8 ECHR requires in environmental matters that States take 'reasonable and appropriate measures' to protect individuals from 'serious damage to their environment'. States have an 'extensive margin of appreciation' in this regard. The ECtHR assesses whether a 'fair balance' has been struck between the interests at stake. The ECtHR also understands this to include economic interests.162.

In several cases of (serious) environmental damage, the ECtHR has ruled that Article 8 ECHR had been violated. Examples of this include cases concerning environmental pollution and nuisance from a waste treatment plant,163.environmental nuisance and health risks from a gold mine,164.severe noise pollution from catering establishments,165.air pollution and health risks from a steel plant,166.nuisance and health damage due to traffic measures,167.environmental pollution from a coal mine,168.safety risks caused by stray dogs,169.environmental nuisance due to a waste crisis,170.groundwater contamination from an illegal cemetery,171.and environmental pollution from a power station.172.

Human rights as a basis for climate commitments?

The case law of the ECtHR on positive obligations under Articles 2 and 8 ECHR, which was discussed a moment ago, is casuistic. Much of the case law concerns fairly clear cases in which, although possibly involving many victims, the danger or environmental damage can be traced back to a certain activity at a certain location (a rubbish tip, a steel plant, a power plant, et cetera). Some cases concern larger-scale activities, involving more actors and more divergent interests (hospitality industry policy, traffic measures, stray dogs, waste policy). Even in the more small-scale cases, general/more general interests and policy themes sometimes play a role in the background (spatial planning, water management, environmental policy, disaster management).

Some authors have argued that Articles 2 and 8 ECHR are not suitable for application to the danger of climate change. In their opinion, particularly problematic is the fact that climate change does no threaten a specific group of potential victims that can be demarcated; it potentially threatens the world's entire population. Moreover, climate change is not caused by one single country or one single source of emissions, but the result of the conduct of many countries and many sources of emissions all over the world. This means that climate change transcends the balancing of general and individual interests that is characteristic for human rights (cf. para. 2.35 above). Combating the danger of climate change requires an assessment of conflicting general interests and, according to these authors, that is not what human rights are intended for.173.Other authors consider the human rights approach of the Court of Appeal to be pre-eminently suitable for the assessment of this case.174.

The question of whether human rights protect not only people as individuals but also humanity as a whole does not need to be answered in these cassation proceedings. This case concerns the question of whether the ECtHR case law on positive obligations under Articles 2 and 8 ECHR offers starting points for assuming an obligation on the State to reduce, or ensure the reduction of, the emission of greenhouse gases from the Dutch territory by 25% by the end of 2020 as compared to the emissions in 1990. In the following paragraphs, four main lines from the ECtHR case law will be discussed, which could provide starting points – taking into account the climatological insights, objectives of international climate policy and standards and principles of international law referred to by the District Court and Court of Appeal – for the assumption of such an obligation.

First main line: preventive legal protection under Articles 2 and 8 ECHR

The positive obligations that the ECtHR has derived from Articles 2 and 8 ECHR are of a preventive nature. In the L.C.B./United Kingdom judgment, a precursor to the aforementioned Osman judgment, the ECtHR already considered that it comes down to whether the government has done what could be expected of it 'to prevent the applicant’s life from being avoidably put at risk'.175.This preventive nature is inherent to the concept of positive obligations as such: they are intended to ensure that the government makes an effort to prevent human rights from being compromised by third parties or external factors.176.It is important to note that this is not an obligation of result: the fact that a person dies does not necessarily imply a violation of the right to life.177.In the words of Gerards, positive obligations are characterised by the fact that they ‘help to ensure the effective enjoyment’ of the human right in question.178.This is without prejudice to the fact that the ECtHR often places high demands on the efforts to be made by the government and that such demands may involve the need to ensure a certain minimum level of protection (see paras. 2.63 et seq. below).

The question is therefore not whether Articles 2 and 8 ECHR protect against future dangers – which they do – but how far this preventive protection goes. According to the ECtHR, the aforementioned Osman obligation to protect those at risk – which is also applied, by analogy, to environmental disasters and dangerous situations179.– applies if the government is aware of a 'real and immediate risk' for persons. In the literature, questions have been raised with regard to the second element of this criterion: the requirement of immediacy. Referring to various ECtHR judgments, Sanderink argues that this requirement has hardly any added value, because it mainly concerns the reality of the risk.180.Gijselaar and De Jong conclude from the ECtHR case law that the point is whether the risk is avoidable: if not, there is an 'immediate risk', even though it will only materialise in the longer term.181.Emaus argues in a more general sense that the ECtHR case law is governed by a 'precautionary principle'.182.

The Taşkin and others/Turkey judgment offers support for this playing down of the requirement of immediacy. In that case, the complainants claimed a violation of Article 8 ECHR on account of environmental risks associated with the use of cyanide in the operation of a gold mine. The Turkish government defended itself by arguing that these risks were 'hypothetical' because they could only emerge in 20 to 50 years. The ECtHR dismissed this defence by ruling that the risks had been identified in several environmental reports. The risks were therefore sufficiently closely linked to the right to private and family life of those living in the vicinity of the gold mine, as protected by Article 8 ECHR. The ECtHR continued:

'If this were not the case, the positive obligation on the State to take reasonable and appropriate measures to secure the applicant’s rights under paragraph 1 of Article 8 would be set at naught.'183.

This finding confirms the preventive nature of the positive obligations. More specifically, it shows that a violation of these obligations does not merely emerge when the risk is almost materialising (the proverbial ‘point of no return’). Risks threatening to occur in the long term, in this case a term of several decades, may also force the government to take preventive measures. The applicability of Articles 2 and 8 ECHR therefore does not require an 'acute' or 'immediate' danger.184.

Even if there is scientific uncertainty about the exact nature of the extent of risks that will or may materialise only over a longer period of time, this does not automatically relieve the government of its obligation to take precautionary measures. This is clear from the Tătar/Romania judgment, in which the ECtHR held that the continued operation of a gold mine was in violation of Article 8 ECHR, in connection with potential health risks for people living nearby, which risks had not been conclusively proven. The ECtHR referred in this context to the precautionary principle ('le principe de précaution'), which has been accepted in international environmental law (see para. 2.74).185.This also shows that in the context of positive obligations, the ECtHR does not require imminent damage and a causal link, nor require irrefutable proof of such: a real risk being caused by the government’s actions is sufficient.186.

Preventive enforcement of human rights can be problematic from a procedural point of view, as far as the procedure before the ECtHR is concerned. After all, on the basis of Article 34 ECHR, complaints can only be submitted by persons who demonstrably qualify as victims. However, the ECtHR has stretched the victim requirement in favour of 'potential victims' and 'inevitable victims'. While it is true that the mere risk of a future human rights violation is insufficient to establish standing for a complaint to the ECtHR, if the government has taken specific steps or rendered decisions that could lead to the alleged human rights violation, such as in the case of an intended deportation or extradition in violation of the ECHR, complaints about this can be brought in Strasbourg. Even if an alleged violation of human rights is not yet an issue but is inevitable in the long run, such as in the event of rules relating to taxes or inheritances that will only be applied in the event of a person’s death, standing has been accepted with complaints about this.187.In this way, the preventive protective scope of the ECHR is also guaranteed from a procedural point of view.

Second main line: general legal protection under Articles 2 and 8 ECHR

In section 2.43, it was shown that States are obliged under Article 2 ECHR to take measures to protect persons at risk. This Osman obligation is not only intended to protect specific persons who are known in advance to be at risk, but also, in certain cases, to provide 'general protection to society' ('une protection générale de la société').188.This is obvious, as the threat emanating from violent persons can affect random victims who cannot be individualised in advance. The nature of the danger calls for a wider scope of application in such cases.

The positive obligations under Article 8 ECHR have also been assigned a general scope of protection. For example, the ECtHR held in Di Sarno and others/Italy and Cordella and others/Italy that the environmental damage in question (a waste crisis and environmental pollution caused by a steel plant, respectively) affected the entire population of the region ('l’ensemble de la population'). In both cases, the ECtHR ruled that Article 8 ECHR had been violated.189.Another illustrative example is the Stoicescu/Romania judgment, in which a violation was ruled to have been committed in connection with the fact that the complainant had been attacked by stray dogs. The Romanian authorities had long been aware of the danger posed by stray dogs - which had developed into 'a public health and safety issue’ - but had done nothing to curb it. The circumstance that the stray dogs obviously did not specifically target the complainant, and the authorities therefore could not foresee that and in what way she would become a victim of such an attack, did not prevent the ECtHR from assuming a violation of Article 8 ECHR. Van de Westelaken argues that the requirement that the potential victims must be identifiable, as laid down in the Osman judgment, has thus been abandoned.190.

In the event of dangers and environmental damage that threaten the whole region or society as a whole, Articles 2 and 8 ECHR proportionally offer protection to the whole region or society as a whole. This is in line with the principle of effective interpretation (see para. 2.37 above): in this category of ‘untargeted’ dangers and environmental damage, setting the requirement that potential victims must be identifiable would undermine the protection offered by Articles 2 and 8 ECHR.

In procedural terms, as well, the ECHR offers scope for general legal protection where necessary to safeguard the effectiveness of the human rights concerned. An example of this is the ECtHR case law on ‘secret surveillance’. According to this case law, the mere existence of national legislation allowing secret surveillance is sufficient to establish standing for a complaint based on Article 8 ECHR from persons subject to that legislation, regardless of whether they actually are or have been exposed to secret surveillance.191.This expansion of the victim requirement enables an abstract assessment of surveillance legislation in the light of Article 8 ECHR. The rationale underlying is, again, the principle of effective interpretation: precisely because citizens cannot know whether they are subject to secret surveillance, Article 34 ECHR cannot be applied in full. Otherwise, the protection offered by Article 8 ECHR would be rendered illusory.

Third main line: assessment of safety and environmental policy under Articles 2 and 8 ECHR

A third main line concerns the margin of appreciation that is afforded to governments, according to the ECtHR, in choosing measures to implement their positive obligations. The ECtHR also applies this margin of appreciation in the context of dangerous activities and environmental damage, but this does not prevent the ECtHR from making an in-depth assessment of the policy choices made by governments. The minimum in this regard is that the measures taken by governments must be appropriate with a view to reducing the danger or the environmental damage in question. More specifically, this means that the measures must be taken in good time and must – at least potentially192.– be effective; see also sections 4.216-4.217 below.193.

An illustrative example is the Öneryildiz judgment, which involved a gas explosion at a Turkish rubbish tip. The Turkish authorities, who had been aware of the risk of explosion for many years but had done nothing to protect the inhabitants of a nearby slum, argued that the resettlement of those inhabitants was a large-scale and costly operation and that humanitarian considerations prevented an immediate evacuation of the slum. The ECtHR rejected those arguments and ruled that Article 2 ECHR had been violated. The ECtHR indicated exactly what measures the Turkish government should have taken and how it should have weighed the interests involved:

'107. The Court acknowledges that it is not its task to substitute for the views of the local authorities its own view of the best policy to adopt in dealing with the social, economic and urban problems in this part of Istanbul. (…).

However, even when seen from this perspective, the Court does not find the Government’s arguments convincing. The preventive measures required by the positive obligation in question fall precisely within the powers conferred on the authorities and may reasonably be regarded as a suitable means of averting the risk brought to their attention. The Court considers that the timely installation of a gas-extraction system at the Ümraniye tip before the situation became fatal could have been an effective measure without diverting the State’s resources to an excessive degree in breach of Article 65 of the Turkish Constitution (see paragraph 52 above) or giving rise to policy problems to the extent alleged by the Government. Such a measure would not only have complied with Turkish regulations and general practice in the area (…), but would also have been a much better reflection of the humanitarian considerations the Government relied on before the Court.'

The inhabitants of the slum also invoked violation of their right to property, as protected by Article 1 of the First Protocol to the ECHR. The Turkish government countered this by arguing that the construction of the slum was illegal and that spatial planning was subject to its discretion. The ECtHR rejected that argument as well. In this context, the ECtHR considered that the discretion of national governments 'in no way dispenses them from their duty to act in good time, in an appropriate and, above all, consistent manner'.194.

The fact that the ECtHR can, if necessary, also make an in-depth assessment of the timing of precautionary measures is evident from the Budayeva and others/Russia judgment, concerning a mudslide caused by poor water management. The Russian government argued in its defence that the timing and severity of the mudslides could not be accurately predicted. The ECtHR ignored this because the government had not explained which measures it had taken to protect the inhabitants of the at-risk area. The ECtHR ruled that Article 2 ECHR had been violated and endorsed the complainants’ view that 'implementing safety measures could have, and should have, taken place earlier'. In his accompanying annotation, Janssen concluded that the ECtHR performs an in-depth assessment of the evidence submitted by governments, and that reliance on the margin of appreciation has no chance of success if the government has no explanation for its failure to act adequately.195.

In the context of Article 8(2) ECHR, as well, which generally affords the national authorities a greater margin of discretion or appreciation than Article 2 ECHR196., the ECtHR can go a long way in assessing the policy choices made. The Fadeyeva/Russia judgment on air pollution and health risks caused by a steel plant is a case in point. In para. 68, the ECtHR stated first and foremost:

'Article 8 has been invoked in various cases involving environmental concern, yet it is not violated every time that environmental deterioration occurs: no right to nature preservation is as such included among the rights and freedoms guaranteed by the Convention (see Kyrtatos v. Greece, no. 41666/98, ECHR 2003-VI, par. 52). Thus, in order to raise an issue under Article 8, the interference must directly affect the applicant’s home, family or private life.'

The Russian government defended itself by arguing that air pollution had been significantly reduced over a period of twenty years and that further reduction was a long-term process. The ECtHR rejected that argument and ruled that Article 8 ECHR had been violated. In that context, the ECtHR noted that previous reduction plans 'did not achieve the expected results' and that the 'deadline for bringing the plant’s emissions below dangerous levels' had been extended repeatedly. The ECtHR did not consider it sufficient that 'significant progress' had been made compared to the distant past. According to the ECtHR, progress in recent years had been 'very slow', noting that 'in certain years pollution levels increased rather than decreased'. The ECtHR recognised that the environmental problem could not be solved in a short period of time. Against this backdrop, it formulated the following assessment framework:

'Indeed, it is not the Court’s task to determine what exactly should have been done in the present situation to reduce pollution in a more efficient way. However, it is certainly in the Court’s jurisdiction to assess whether the Government approached the problem with due diligence and gave consideration to all the competing interests. In this respect the Court reiterates that the onus is on the State to justify, using detailed and rigorous data, a situation in which certain individuals bear a heavy burden on behalf of the rest of the community.'

In this case, the ECtHR considered that the Russian government did not succeed in providing evidence of 'due diligence', in particular because it had not clarified the precise nature of the reduction policy in respect of the steel plant.197.

The due diligence criterion from the Fadeyeva/Russia judgment was repeated in the 2017 Jugheli and others/Georgia judgment and the 2019 Cordella and others/Italy judgment. Both of these judgments concerned environmental pollution (by a power plant and steel plant, respectively) and in both judgments it was concluded on the basis of a careful and in-depth assessment of the governments’ considerations that the environmental policy pursued did not meet the due diligence requirement ('diligence voulue').198.

The margin of appreciation that is afforded to governments, according to the ECtHR, in environmental matters is therefore certainly not unlimited and absolute. An important point of view for the ECtHR seems to be whether the environmental policy pursued is consistent, properly substantiated and in line with national laws and regulations. In the literature, this is also referred to as the 'rule of law' criterion.199.If the government violates national rules or is unable to justify its own policy, the ECtHR will adopt a stricter stance. In such cases, there seems to be a smaller margin of appreciation. An illustrative example is the Dubetska and others/Ukraine judgment, concerning environmental pollution from a coal mine. The ECtHR found that the government’s policy towards the coal mine was characterised by 'numerous delays and inconsistent enforcement'. In spite of the 'wide margin of appreciation' that the ECtHR afforded in principle to the government in this case, the ECtHR ruled that Article 8 ECHR had been violated because the coal mine violated national rules and the government had done nothing to protect people living nearby from the pollution.200.

With regard to the above, it must be borne in mind that the margin of appreciation arises from the principle of subsidiarity enshrined in Article 1 ECHR.201.This principle entails that the protection offered by the ECHR must be realised primarily by the national authorities (including the national courts). The ECtHR does not act as a ‘fourth instance’, as if it were the country’s highest judiciary: it assesses complaints about violations of the treaty. The ECtHR has considered the following on this matter:

'The doctrine of the margin of appreciation has always been meant as a tool to define relations between the domestic authorities and the Court. It cannot have the same application to the relations between the organs of the State at the domestic level.'202.

For this reason, national courts are not required to exercise restraint in those areas where the ECtHR affords the national authorities a margin of appreciation.203.In the literature, the opposite is argued: where the ECtHR exercises restraint on account of the principle of subsidiarity, the national courts must perform a more in-depth assessment.204.The Fabris/France judgment supports this approach.205.Incidentally, it cannot be inferred from this that the Fabris/France judgment encourages an extensive substantive interpretation of the ECHR. The foregoing is also without prejudice to the possible existence of other reasons for restraint on the part of the court (e.g. on the basis of the national relationships between the state powers, to be discussed in Chapter 5 below). The concept of a margin of appreciation takes on a different meaning in that case, in which the focus is no longer on the relationship between the ECtHR and the national court. Application by the national court raises the question of what margin of discretion or appreciation the national court affords the authorities in its own country. It already follows from the text of the treaty that generally speaking, this margin is more limited with regard to the right protected in Article 2 ECHR than with regard to the rights protected in Article 8 ECHR.206.

Fourth main line: the ECtHR’s common ground method

The last main line that deserves to be mentioned concerns the way in which the ECtHR interprets human rights in areas where the ECHR does not provide a definitive answer to the precise content of the obligations incumbent on the Contracting States. The ECtHR considers the ECHR to be 'a living instrument which (...) must be interpreted in the light of present-day conditions'.207.In connection with this, the Court applies the 'common ground' or 'consensus' method when answering new questions of law. This method of determining the law entails that the ECtHR seeks to tie in with views that are widely shared in the Contracting States and in an international context. In this context, in addition to the national case law in the Contracting States, the ECtHR can also consider non-ratified treaties and ‘soft law’ in its assessment; the concept of ‘soft law’ has already been discussed in sections 2.31 et seq. above.208.

In the Demir and Baykara/Turkey judgment, the ECtHR described the common ground method as follows:

'85.The Court, in defining the meaning of terms and notions in the text of the Convention, can and must take into account elements of international law other than the Convention, the interpretation of such elements by competent organs, and the practice of European States reflecting their common values. The consensus emerging from specialised international instruments and from the practice of contracting States may constitute a relevant consideration for the Court when it interprets the provisions of the Convention in specific cases.

86.In this context, it is not necessary for the respondent State to have ratified the entire collection of instruments that are applicable in respect of the precise subject matter of the case concerned. It will be sufficient for the Court that the relevant international instruments denote a continuous evolution in the norms and principles applied in international law or in the domestic law of the majority of member States of the Council of Europe and show, in a precise area, that there is common ground in modern societies (…).'209.

It is already clear from this description that in order to find common ground, full consensus between the Contracting States is not required. For example, in 2002 the ECtHR accepted a right to recognition of gender reassignment despite 'the lack of a common European approach' towards the subject matter.210.The ECtHR referred to 'the clear and uncontested evidence of a continuing international trend’.211.

The common ground method is somewhat comparable to the reflex effect that national courts, in implementing open standards into national law, can attribute to treaty provisions and ‘soft law’ that have no direct effect.212.This explains why the Court of Appeal in its contested judgment reached the same conclusion on the basis of Articles 2 and 8 ECHR as the District Court did on the basis of Article 6:162 DCC: for the concrete implementation of the reduction obligation, the District Court and the Court of Appeal sought to draw on the same climatological insights, objectives of international climate policy and principles of international law.

The ECtHR case law so far does not provide a definitive answer to the question of whether and, if so, precisely which positive obligations arise from Articles 2 and 8 ECHR with regard to climate change.213.This does not mean that the national court should refrain from rendering an opinion on the matter. The following may be relevant in this context.

The common ground method and international environmental law

International environmental law is a specific part of international law that is governed by its own rules and principles.214.Particularly important in this case are the ‘no harm rule’, which means that a State may not use or allow the use of its own territory for activities that harm other States, and the ‘precautionary principle’, according to which a lack of scientific certainty should not be a reason to postpone effective and proportionate measures to prevent serious and irreversible damage, to the environment.215.Following the example of the District Court, the Court of Appeal based its opinion in part on these rules and principles of environmental law.216.

Focusing on climate change issues,217.relevant is the fact that Article 2 UNFCCC requires States to reduce greenhouse gas emissions within a time-frame sufficient to allow ecosystems to adapt naturally to climate change, to ensure that food production is not threatened and to enable economic development to proceed in a sustainable manner. The principles formulated in Article 3 UNFCCC (i.e. the principles of equity, precaution and sustainability) referred to by the Court of Appeal in para. 7 are particularly important in this context.

Of particular importance is the principle of equity, which means, among other things, that Contracting States must take action against climate change in accordance with their 'common but differentiated responsibilities and respective capabilities'. More specifically, it emerges from this principle that the countries considered to be industrially developed countries at the time the UNFCCC was concluded, including the Netherlands, ‘should take the lead’ in combating climate change and its adverse consequences (Article 3(1) UNFCCC), as the Court of Appeal also found in para. 9. Wewerinke-Singh deduces from this that, in a human rights approach to climate change, 'the standard of care may differ from one State to another'.218.

The reduction commitments agreed upon in the Kyoto Protocol between a number of Annex I countries for the period 2008-2012 have, according to prevailing insights, the status of minimum standards. They do not relieve states of their general obligations under international law, such as obligations under human rights conventions or the no harm rule. This is clear from the statements made by some countries upon signing the UNFCCC,219.but also follows from the nature of the Kyoto Protocol itself.220.

From an international environmental law point of view, the Paris Agreement is important as well. This agreement recognised 'the need for an effective and progressive response to the urgent threat of climate change'. It also stipulates that the global warming should remain 'well below 2ºC', but preferably aiming for 1.5ºC. To achieve this goal, the Contracting Parties, including the Netherlands, set the objective 'to reach global peaking of greenhouse gas emissions as soon as possible (…) and to undertake rapid reductions thereafter in accordance with best available science'.221.

The common ground method and human rights-based climate commitments

From a human rights perspective, relevant is the fact that in recent years the link between climate change and human rights has been increasingly explicitly established at the international level. For instance, the contribution of the UN High Commissioner for Human Rights to the 2015 climate conference in Paris includes the following:

'Climate change impacts, directly and indirectly, an array of internationally guaranteed human rights. States (duty-bearers) have an affirmative obligation to take effective measures to prevent and redress these climate impacts, and therefore, to mitigate climate change, and to ensure that all human beings (rights-holders) have the necessary capacity to adapt to the climate crisis.'222.

This does not, however, exclusively concern Articles 2 and 8 ECHR. An explicit reference to human rights can be found in the introduction of the aforementioned Paris Agreement (2015):

'Acknowledging that climate change is a common concern of humankind, Parties should, when taking action to address climate change, respect, promote and consider their respective obligations on human rights, the right to health, the rights of indigenous peoples, local communities, migrants, children, persons with disabilities and people in vulnerable situations and the right to development, as well as gender equality, empowerment of women and intergenerational equity.'223.

The 2015 UNEP report ‘Climate Change and Human Rights’ formulates five human rights obligations in relation to climate change, including mitigation and adaptation obligations.224.In this context, reference can also be made to a ‘Statement on the human rights obligations related to climate change’ by the UN Special Rapporteur on Human Rights and the Environment. With reference to the ‘Framework principles on human rights and the environment’225.drawn up earlier in UN context, the Special Rapporteur argues that it follows from this that humans rights require States 'to establish, implement and enforce effective laws and policies to reduce greenhouse gas emissions'.226.Reference should also be made to the previously mentioned Oslo Principles on Global Climate Obligations, drawn up by a group of experts in the field of international law, human rights and environmental law. It argues, including on the basis of human rights, that States with excessive emissions of greenhouse gases are obliged to reduce emissions 'within the shortest time feasible'.227.

The international sources refer in turn to national court decisions in climate cases.228.A national court judgment referred to in many of these international sources, in addition to the judgments by the District Court and the Court of Appeal in the Urgenda case, is the Leghari judgment rendered by the Lahore High Court in 2015. In summary, this case concerned the question of whether the Pakistani government was obliged to implement a 2012 policy framework, the ‘National Climate Policy and Framework’, which included mitigation and adaptation measures. The Pakistani court considered, with reference to various national and international sources, that 'the delay and lethargy of the State in implementing the Framework offend the fundamental rights of the citizens'. In an interim decision, that court established, among other things, a ‘Climate Change Commission’, to monitor the implementation of the climate policy.229.

In her study into climate obligations under international law, Wewerinke-Singh concludes that human rights oblige States to adapt and mitigate.230.In their recent preliminary advice for the Dutch Lawyers’ Association, Arts and Scheltema defended the view that human rights only impose an adaptation obligation on States – i.e. to address the consequences of climate change – and not a mitigation obligation – i.e. to prevent dangerous climate change by reducing emissions.231.In general, this point of view does not seem to be supported by the international sources discussed above.232.Hey and Violi state in their 2018 preliminary advice for the Association of International Law that the climate cases that have been instituted throughout the world thus far relate to mitigation measures.233.Spier rejects the view expressed by Arts and Scheltema. According to him, it is actually the view 'that excessive emissions are a human rights violation (...) that is rapidly gaining ground'.234.Spier points out, moreover, that adaptation alone is far from enough to eliminate all the consequences of climate change.235.

From an ECHR perspective, it can be added that the ECtHR seems to prefer mitigation (prevention) over adaptation (harm reduction). Illustrative is the Kolyadenko/Russia judgment, which concerned a flooded residential area because a large volume of water had to be released from a reservoir after heavy rains. According to the ECtHR, the Russian authorities should have prevented the flooding by keeping a nearby river clean 'with a view to mitigating, if not preventing, the risk and consequences of flooding in the event of the urgent evacuation of water from the reservoir'.236.In the ECtHR’s view, adaptation is in order where mitigation is impossible or cannot be demanded of States, such as in the case of unavoidable natural disasters. This is clear, for example, from the Özel et al./Turkey judgment concerning the collapse of buildings due to an earthquake, in which the ECtHR considered:

'La Cour observe que les séismes sont des évènements sur lesquels les États n’ont pas de prise et pour lesquels la prévention ne peut consister qu’à adopter des mesures visant à la réduction de leurs effets pour atténuer au maximum leur dimension catastrophique. À cet égard, la portée de l’obligation de prévention consiste donc essentiellement à adopter des mesures renforçant la capacité de l’État à faire face à ce type de phénomènes naturels violents et inattendus que peuvent être les tremblements de terre.'237.

The international legal sources just discussed seem able to provide common ground for the finding that Contracting States are obliged by virtue of human rights to seriously reduce greenhouse gas emissions from their territory: a far-reaching best-efforts obligation. The legal sources in question do not answer the questions of within what time period and to what extent reduction is required. In order to answer that question, the District Court and Court of Appeal have sought to establish a connection with, among other things, the various COP decisions that have been rendered in UN context since the publication of the AR4 report.238.The Court of Appeal’s reasoning based on this is contested in grounds for cassation 4 through 8. Those complaints are discussed in Chapter 4 of this opinion.

The first three grounds for cassation relate to the substantiation of the order under human rights law. These grounds are aimed at various opinions of the Court of Appeal and basically concern three subjects, each of which are discussed below in separate sections.

Requirement of specific risks for residents of the Netherlands? (grounds for cassation 1.1 and 2)

Ground for cassation 1 is aimed at paras. 40-43, where the Court of Appeal explained the legal framework, specifically: Articles 2 and 8 ECHR and the interpretation thereof. Ground for cassation 1.1 is of an introductory nature. The complaint entails that in its description and further application of the legal framework, the Court of Appeal based itself on an incorrect interpretation of the law. In particular, the Court of Appeal allegedly failed to appreciate that in order to assume a positive obligation under Article 2 and/or Article 8 ECHR, there must be a real and immediate risk of violation of the rights protected under Article 2 and/or Article 8 ECHR of 'specific or specifically identifiable persons or groups' that are located within the jurisdiction of the State. That complaint is fleshed out in ground for cassation 2, which is directed against paras. 44-45.

In para. 45, the Court of Appeal concluded that there was ‘a real threat of dangerous climate change, resulting in the serious risk that the current generation of citizens will be confronted with loss of life and/or a disruption of family life’. The Court of Appeal ruled that on the basis of Articles 2 and 8 ECHR, the State is obliged to provide protection against this real threat. The State does not dispute the facts on which the Court of Appeal based these opinions as set out in para. 44. Its complaints are directed against the consequences that the Court of Appeal has attached to the facts in para. 45.239.These complaints entail the following.

First, the State has argued that also in view of Article 1 ECHR, Articles 2 and 8 ECHR merely give rise to obligations in respect of persons who are subject to the jurisdiction of the State.240.According to the State, this means that a positive obligation as presumed by the Court of Appeal can only exist if the risk identified by the Court of Appeal of dangerous climate change occurs specifically in the Netherlands, or at least with regard to persons who are located within the jurisdiction of the State of the Netherlands (within the meaning of Article 1 ECHR). Considered in that light, in the opinion of the State this ruling is legally incorrect or insufficiently substantiated (ground for cassation 2.1).241.

Secondly, the State has argued that in view of the territoriality principle in Article 1 ECHR, decisive is where the consequences of the emission of greenhouse gases in the Netherlands occur. If the Court of Appeal is of the opinion that the State is obliged on the basis of Articles 2 and 8 ECHR to take reduction measures regardless of the location on the planet where the consequences of the emission of greenhouse gases in its territory occur, in the opinion of the State that opinion is incorrect: on the basis of those articles, the State can only be obliged to take reduction measures that prevent or limit the consequences of climate change in respect of persons who are subject to the jurisdiction of the State as referred to in Article 1 ECHR (ground for cassation 2.2).

Thirdly, the State has argued that in order to assume a reduction obligation based on Article 2 or Article 8 ECHR, the State must know, or at least ought to know, of the specific consequences of climate change on a demarcated area designated for human habitation. The State has emphasised that the ECHR does not entail any general right to protection of the environment.242.According to the State, Article 8 requires a causal connection between the activity (here: the emission of greenhouse gases) and the specific negative impact on an individual's human rights caused by that activity. A negative impact on society as a whole is insufficient. This is why the Court of Appeal could not base the State's positive obligation on the general consequences of climate change mentioned in para. 44 - at least not without further reasons. By extension, the State has argued that the Court of Appeal ought to have investigated 'the probability of said consequences (...) occurring in a demarcated area within the Netherlands designated for human habitation' (ground for cassation 2.3).

In summary, the State has argued that the Court of Appeal ought to have established: which specific rights protected by Articles 2 and/or 8 ECHR are at risk of being violated by the consequences of climate change mentioned in para. 44 and in what way, and which persons or groups that are located within the jurisdiction of the State are exposed to that risk (ground for cassation 2.4).

Fifthly, the State has argued that in order to assume a positive reduction obligation based on Article 2 or Article 8 ECHR, a threat must exist that is not only real but also immediate. In the opinion of the State, it must be plausible that the consequences named by the Court of Appeal in para. 44 'will also materialise in the short term'. This is not the case, according to the State, because for the time being, the 2ºC target being exceeded is not at issue. If the Court of Appeal has applied the precautionary principle, its decision is also incorrect, or at least incomprehensible without further reasons. According to the State, that principle exclusively applies to 'clearly identifiable risks to a certain living environment'. The Court of Appeal did not establish such risks for the Netherlands. In the opinion of the State, the fact that the consequences of climate change cannot be avoided in the long term if a reduction of at least 25% has not been realised by the end of 2020 does not entail the existence of 'consequences of climate change that will materialise in the short term' (briefly put, according to ground for cassation 2.5).

Sixthly, the State has complained that the Court of Appeal failed to appreciate that an obligation to protect 'all residents of the Netherlands' against 'any form of dangerous consequences of climate change' cannot be based on Article 2 and/or Article 8 ECHR. Furthermore, in the opinion of the State the interests of the residents of the Netherlands are 'not congruent' on this point, because 'a measure that protects one resident may have harmful impact on another resident' (ground for cassation 2.6).

These complaints can be discussed jointly. First and foremost: the issue addressed by these grounds for cassation was not discussed on appeal. The State has acknowledged the climate risk and the need to reduce greenhouse gas emissions, and has also endorsed the 2°C target advocated by Urgenda. In addition, the State has made no reservation requiring specific risks for residents of the Netherlands in order to presume a reduction obligation borne by the State, nor has it argued that such specific risks are absent.243.The ground for cassation does not provide any references in the procedural documents on appeal to the State’s assertions addressing this issue.244.This means that these complaints may remain moot, as a new defence may not be conducted in proceedings for cassation.245.We will briefly discuss the complaints nevertheless.

In the previous chapter, it already emerged that in defining the scope of protection of Articles 2 and 8 ECHR, weight should be assigned to the nature of the danger involved; see section 2.59. With ‘untargeted’ risks, such as earthquakes or harm to the living environment, with a view to the principle of effective interpretation the requirements to be imposed on the specification of the interests involved are not as high, as discussed in section 2.37 above. In that sense, Article 2 ECHR offers 'general protection to society' in such cases. Positive obligations to protect society may also ensue from Article 8 ECHR (see section 2.60 above). Demonstrable damage or threat of damage is not required in assuming a violation of Articles 2 and 8 ECHR, nor required when pronouncing an order based on Article 3:296 DCC. The issue is whether there is a real risk of harm to the interests of individuals protected by Articles 2 and 8 ECHR (cf. section 2.57 above).

The danger of climate change due to an increase in the planet’s temperature is characterised by the fact that this is a global threat to the lives and family lives of individuals throughout the world, in a manner that makes it impossible to exhaustively specify who will suffer as a result, where on the planet, and at what time. This conclusion does not prejudice the fact that certain groups of residents may be especially vulnerable to certain consequences of climate change. For example, the increased sea level feared - one of the harmful consequences of climate change mentioned in para. 44 - threatens people living in low areas in particular, including large parts of the Netherlands.

The State acknowledges all of this: it is the essence of its position that climate change is a global issue that must be addressed globally.246.The fact that the dangers of climate change cannot be translated into specific risks for individual persons can be deemed a fact that is generally known. The court may indicate which threats are involved, as the Court of Appeal did at the third and fourth bullet points of para. 44. However, the State is asking the Court of Appeal to do the impossible by demanding a specification of the dangers caused by climate change to specific or specifically identifiable individuals or groups located within the jurisdiction of the State. Put differently: if the opinion as argued by the State were followed, Articles 2 and 8 ECHR would not offer any more protection against climate change than possibly obliging the State to take adaptation or other measures after the fact to combat the consequences of climate change. As explained, some authors do indeed defend that position.247.

Weighing the facts as established is reserved for the Court of Appeal; those facts cannot be weighed again in proceedings for cassation. It emerged in Chapter 2 that the case law of the ECtHR offers starting points for the obligation of the State to reduce, or ensure the reduction of, the emission of greenhouse gases, as assumed by the Court of Appeal. This is because the ECHR requires effective and active protection of the rights safeguarded by Articles 2 and 8 ECHR (see section 2.37 et seq.). If possible, that protection must be realised through preventive action (section 2.53 et seq.), and it extends to society as a whole in specific cases. The position that human rights may oblige states to mitigate is also gaining support in the international context (section 2.79 et seq.). In light of the common ground method applied by the ECtHR itself, the latter is an important viewpoint that supports the reduction obligation derived by the Court of Appeal from Articles 2 and 8 ECHR.

The Court of Appeal based its reduction order on the sum of the specific risks in para. 44 that - also - threaten residents of the Netherlands, and not on one general climate risk that threatens the entire world's population. The literature refers to an 'accumulation of the threatened violations of the human rights of individuals'.248.It would be extraordinary for a violation of collective human rights not to be covered by Articles 2 and 8 ECHR while each of some innumerable violations on a smaller scale would fall within the scope of those articles. The circumstance that Article 34 ECHR does not allow an actio popularis does not detract from this. Article 34 ECHR merely governs access to the ECtHR, as held by the Court of Appeal in para. 35, which is not disputed in these proceedings for cassation.

There is no violation of the principle of territoriality in view of the foregoing, as the Court of Appeal limited its judgment to the interests of residents of the Netherlands.249.Ground for cassation 2.2 fails for this reason.

The State’s assertion that for the time being, there is no 'immediate' threat to the Netherlands (ground for cassation 2.5) does not change the foregoing. Firstly, the positive obligations from Articles 2 and 8 ECHR are of a preventive nature. According to the ECtHR, the fact that the threatening danger may not materialise for decades to come does not rule out the need to take precautionary measures now, even if the exact nature and scope of those risks are still uncertain (see section 2.53 et seq. above). Secondly, the danger on which the Court of Appeal based the reduction order is not hypothetical: it already latently exists. The latter will also be addressed when discussing the second question.

Following the foregoing, the other complaints need no separate discussion. The conclusion is that ground for cassation 1.1 and all of the complaints from ground for cassation 2 fail.

Margin of appreciation in respect of the reduction pathway (grounds for cassation 1.2 and 1.3)

Grounds for cassation 1.2 and 1.3 - directed against paras. 40-43 - concern the question of whether and, if so, to what extent the State is entitled to any margin of appreciation in determining its policy in respect of reducing the emission of greenhouse gases. Referring to the case law of the ECtHR discussed above in section 2.47 et seq. on the application of Article 8 ECHR to environmental issues, the State advocates a 'wide margin of appreciation'. The Court of Appeal was only entitled to assess whether the State has found a fair balance between the individual and general interests to be weighed. The choice of the 'reduction pathway' - meaning the time and speed at which measures to reduce emissions are taken - is included in its margin of appreciation, according to the State. The State believes this involves one of its key objections to the challenged opinion.250.Grounds for cassation 8.3 and 8.4 elaborate on this with more targeted complaints in connection with the State's position that a 'postponed' reduction pathway - meaning a less far-reaching reduction in the period until the end of 2020 and increasing reduction efforts in the respective subsequent periods until 2030 and 2050 - will also lead to the realisation of the 2ºC target.251.

The margin of appreciation assigned by the ECtHR to national authorities in the application of Articles 2 and 8 ECHR, with the ensuing fair balance criterion, is not intended to govern internal domestic relationships, such as the national court in respect of the national executive or the legislator. The margin of appreciation doctrine ensues from the principle of subsidiarity, which entails that the legal protection offered by the ECHR must be primarily realised on the national level. Against that backdrop, the national court is not necessarily required to exercise restraint in areas where the ECtHR applies a margin of appreciation (see section 2.69).

The State argues in favour of analogous application of the margin of appreciation doctrine by the national courts.252.Henceforth in this conclusion, we will presume by way of assumption that the margin of appreciation doctrine is suitable for analogous application in national relationships: the State is basically saying that it is entitled to a wide margin of discretion and appreciation. Relevant is the fact that the ECtHR assigns a wide margin of appreciation to the national authorities in its assessment of certain cases of violation of Article 8 ECHR; the second paragraph of that article governs the possibility of intervention by authorities in the exercise of one of the protected rights from the first paragraph of that article. By contrast, Article 2 ECHR has no second paragraph that allows restrictions. Within the context of Article 2 ECHR - life-threatening situations - as a rule the ECtHR does not apply any margin of appreciation. This does not prejudice the fact that in the assessment of positive obligations based on Article 2 ECHR, the ECtHR assigns a certain margin of appreciation to the national authorities, by not requiring measures that result in an 'impossible or disproportionate burden' (see section 2.43 et seq. above).

The Court of Appeal did not fail to appreciate all of this. Its opinion was based on the following steps: the State endorses that in order to prevent dangerous climate change, the increase in the world’s temperature must be less than 2ºC (para. 30). If this target is not realised, there is a serious risk that the current generation of residents of the Netherlands will be faced with loss of life or disruption of their family life (para. 45). In order to realise the 2ºC target, reducing emissions by 25 to 40% in 2020 is deemed necessary (para. 46 et seq.). A reduction obligation of 25% at the end of 2020 is therefore in line with the State's duty of care as ensues from Articles 2 and 8 ECHR (para. 53).

This strongly abbreviated depiction of the reasoning shows that the Court of Appeal did not base its opinion on the - future and general - danger of climate change as such, but rather based it on the specific, already latently existing danger that the 2ºC target will not be realised, with all of the risks this involves for residents of the Netherlands. For various reasons, the Court of Appeal deems a reduction of at least 25%, to be realised in 2020, necessary in order to rein in this danger, to wit: the danger of not realising the 2ºC target, with all of the ensuing consequences. The complaints directed against this opinion will be discussed in Chapter 4. Furthermore, the Court of Appeal acknowledges that the Netherlands cannot solve the climate issue on its own (para. 62).

The basis on which the Court of Appeal based its opinion that below the minimum of 25% reduction in 2020, the State has no margin of appreciation in respect of the reduction pathway, also follows from the foregoing. The 2ºC target is established between the parties. A reduction of at least 25% before the end of 2020 is necessary, according to the Court of Appeal’s reasoning, if that target is to be realised. The State does not have the discretion to choose to postpone this reduction until a later point in time, as this would insufficiently rein in the danger of the 2ºC target not being realised. Incidentally, in the choice of the measures to be taken and the instruments to be used to that end, the State does have the margin of appreciation it is advocating (para. 74).

Regardless of the outcome of the complaints about the technical climatological substantiation of this opinion of the Court of Appeal, to be discussed in Chapter 4, the reasoning applied by the Court of Appeal in itself certainly is in line with the case law of the ECtHR regarding positive obligations based on Articles 2 and 8, respectively, of the ECHR. It was already demonstrated above that within the context of dangerous activities and harm to the environment, the ECtHR intensively assesses the policy considerations as weighed by the national authorities. More specifically, it was shown that their margin of appreciation does not relieve states of their obligation to 'act in good time, in an appropriate and, above all, consistent manner' (see section 2.64 above). The complaints are based on an incorrect interpretation of the law in so far as they entail that the margin of appreciation doctrine impedes an intensive or other assessment by the court of the time and speed of the reduction measures.253.

With all of the foregoing, it must not be forgotten that the Court of Appeal certainly did assign a certain margin of appreciation to the State in various respects. A margin of appreciation was taken into account in the opinion that departing from a necessary reduction in emissions of 25-40% in 2020, the order issued does not go beyond a reduction of 25% in 2020. Furthermore, like the parties, the Court of Appeal departed from the 2ºC target and the 450 ppm scenario rather than from the target of 1.5ºC laid down in the Paris Agreement. The Court of Appeal emphasised all of this in para. 50, where it held that it did not apply ‘overly pessimistic starting points’ in determining the State's duty of care.

The conclusion is that grounds for cassation 1.2 and 1.3 miss the mark.

No standing due to lack of similar interests? (ground for cassation 3)

Ground for cassation 3 is directed against paras. 35-38, where the Court of Appeal held that Urgenda has standing by virtue of Article 3:305a DCC and has a sufficient interest in the reduction order being sought. The State has questioned whether the interests of residents of the Netherlands protected by Articles 2 and 8 ECHR in connection with climate change are similar interests within the meaning of Article 3:305a(1) DCC. The State has not disputed Urgenda’s standing to bring a class action to protect the living environment. The purport of the complaints is that the Court of Appeal should have held that Urgenda has no standing in so far as its claim is based on Articles 2 and 8 ECHR.254.To that end, the State has argued that the ECHR 'only guarantees individual rights' and does not protect 'society as a whole'. The similarity requirement from Article 3:305a DCC therefore entails, in the opinion of the State, that the Court of Appeal should have determined 'which interests protected by Article 2 and/or Article 8 ECHR are impacted in what way and in respect of which individuals or groups'.

It must be noted first and foremost that this question, like the first question on which it elaborates (see section 3.10 above), was not discussed in the fact-finding instances. As concluded by the Court of Appeal in para. 37, it was 'not in dispute' between the parties that Urgenda has standing in so far as it is taking action against the emission of greenhouse gases in the territory of the Netherlands on behalf of the current generation of Dutch residents. The State is disputing this conclusion in the proceedings for cassation. In this regard, the State refers to its assertion that pursuant to Article 34 ECHR, Urgenda cannot directly rely on Article 2 and/or Article 8 ECHR.255.In the State’s opinion, the Court of Appeal should have interpreted this assertion as a defence as to standing. In the alternative, the State has argued that the Court of Appeal should have investigated at its own initiative whether the interests being served by Urgenda with reliance on Articles 2 and 8 ECHR are 'similar' within the meaning of Article 3:305a DCC (ground for cassation 3.5).

In para. 35 the Court of Appeal answered the question of whether the victim requirement from Article 34 ECHR impedes Urgenda’s reliance on the ECHR rights of Dutch residents within the context of a class action pursuant to Article 3:305a DCC. There, the Court of Appeal ruled that Article 34 ECHR merely governs access to the ECtHR, and does not impede reliance on ECHR rights in a class action pursuant to Article 3:305a DCC. This opinion rightly256.was not disputed in the proceedings for cassation.

This question of the 'carry-over effect' must be distinguished from the question of standing discussed here, and therefore from the question of whether the interests being served by Urgenda are similar within the meaning of Article 3:305a(1) DCC. According to the current status of the case law, the similarity requirement from Article 3:305a(1) DCC does not create a standing requirement to be assessed by the court at its own initiative. The interest requirement laid down in Article 3:303 DCC - which is partly an extension of the similarity requirement (cf. section 2.7) - should be applied by the court at its own initiative according to prevailing insights.257.

In any event, there is no room for application by the court of the similarity requirement at its own initiative when the facts mutually asserted by the parties give no point of reference for doing so. In this case, as explained, there was no discussion in the proceedings before the District Court and the Court of Appeal about the nature of the climate danger (cf. section 3.10 above). Consequently, the similarity of the interests involved was not a subject of discussion between the parties. The State’s positions in this regard in its grounds for cassation - phrased generally, with no reference to the relevant sources in the procedural documents258.- are new elements of the debate that are inadmissible in proceedings for cassation. There was no room for an investigation of the similarity requirement by the Court of Appeal at its own initiative. Superfluously, the following is noted in this regard.

The case law of the ECtHR regarding positive obligations from Articles 2 and 8 ECHR offers no support for the position argued by the State that the ECHR 'only protects individual rights'. On the contrary: the ECtHR has ruled that Article 2 ECHR offers 'general protection to society' in certain cases, and has also assigned a general scope of protection to Article 8 ECHR where the ECtHR deemed this necessary for the sake of the effectiveness of the rights involved. The generality of State’s position that the case law being referred to 'always [concerns] damage that has already been suffered by a specific group of people, and caused by a specific act or omission by these national authorities',259.is incorrect. For example, the complainant in the Stoicescu/Romania case (about stray dogs260.) was not part of a 'specific group' and had not yet suffered damage at the time the government was obliged to take measures to protect her from that danger. We also refer to the judgment in the Campeanu/Romania case.261.

Furthermore, systematic interpretation of the ECHR262.does not seem to support the State’s position, according to which the scope of protection of Articles 2 and 8 ECHR is limited by the victim requirement from Article 34 ECHR. Articles 2 and 8 ECHR are in Section I of the convention, the title of which is 'Rights and Freedoms'. Article 34 is in Section II, entitled 'European Court of Human Rights'. The latter section contains procedural provisions governing access to the ECtHR, as rightly concluded by the Court of Appeal in para. 35, focusing on Article 34 ECHR, undisputed in the proceedings for cassation.

The principles of effective interpretation and subsidiarity inherent in Article 1 ECHR provide no support for the State’s position, either. Those principles actually advocate assigning full effect to ECHR rights on the national level, from the procedural aspect, as well (cf. sections 2.37 and 2.39 above). It is not in dispute that Article 3:305a DCC offers the necessary room for the representation of general environmental and other interests in a class action on the national level. It is simply a fact that ECHR rights are applied in national practice in class actions by virtue of Article 3:305a DCC.263.The Supreme Court also assesses general policy choices made by the national authorities based on Articles 2 and 8 ECHR outside of the framework of class actions.264.The Administrative Jurisdiction Division of the Council of State does so, as well.265.Its recent decision on gas extraction in Groningen and the accompanying earthquake risk is an example of this. Briefly put, the Division ruled with reference to Articles 2 and 8 ECHR that the Minister must more comprehensibly explain the manner in which gas extraction will be terminated and the reasons why that termination cannot be realised more quickly.266.

The conclusion is that the complaints in ground for cassation 3 fail.

4. Reduction of greenhouse gas emissions in the Netherlands by at least 25% in 2020 (grounds for cassation 4-8)

Introduction

This part of the opinion concerns the substantiation of the Court of Appeal's rulings that a reduction of greenhouse gas emissions in the Netherlands of at least 25% (as compared to 1990) in 2020 is necessary and in line with the State's duty of care.267.That substantiation has both factual and juridical components. In short, this concerns the following. The parties concur on the 2ºC target. It has been established as fact that in order to realise the 2ºC target, greenhouse gas emissions must be reduced more than they currently are. This scientific climate insight can be translated into a certain reduction target for the Netherlands - of at least 25% in 2020 - based on various points of reference. The ruling that the Netherlands must individually endeavour to contribute to achieving the 2ºC target, even though the Netherlands cannot prevent global warming on its own, without contributions from other countries, is a legal opinion.

This part of the opinion firstly provides a summary of the legal and factual information on which the Court of Appeal based its rulings.

To that end, inventory is then taken of the relevant legal and policy framework, in particular in so far as that framework pertains to targets for the reduction of greenhouse gases (section 4.5 et seq.). This is followed by a discussion of the IPCC reports relevant to the debate in this case, specifically the Fourth Assessment Report from 2007 (‘AR4’), in which the reduction target applied by the Court of Appeal of 25-40% is mentioned, and the most recent Fifth Assessment Report from 2013-2014 (‘AR5’) (section 4.34 et seq.).

We will then discuss the facts established by the Court of Appeal in respect of climate change, with a further assessment of the connection between the 2ºC target, the carbon budget and emission reductions (section 4.49 et seq.). Next we will summarise the Court of Appeal's assessment of the facts, culminating in its opinion that the Netherlands must reduce greenhouse gas emissions in 2020 by at least 25% as compared to 1990 (section 4.54 et seq.).

After this, the State's complaints directed against this in grounds for cassation 4 through 8 will be summarised and discussed based on the subjects mentioned in section 4.84 et seq.

The legal and policy framework268.

UNFCCC. On the international level, the 1992 UN Climate Convention is the basis for the climate agreements relevant to these proceedings. See in this regard section 1.2(xiv) et seq. The following subjects are discussed in more detail below: (i) Annex I countries, (ii) the COPs, and (iii) the Paris Agreement.

Annex I countries. In part, the UN Climate Convention is based on the principle that the parties should protect the climate system for the benefit of present and future generations of humankind, 'on the basis of equity and in accordance with their common but differentiated responsibilities and respective capabilities'. 'Accordingly, the developed country Parties should take the lead in combating climate change and the adverse effects thereof' (Article 3(1)).

In Article 4(2), the UN Climate Convention describes the obligations of the developed country parties and the other parties included in Annex I. In the procedural documents, these parties are referred to as the Annex I Countries. The Netherlands is one of the Annex I countries.

The Annex I countries undertook obligations that include adopting policy and taking corresponding measures regarding the mitigation of climate change, including policy and measures adopted by regional organisations for economic integration. The premise in that regard is that these developed countries should take the lead in reversing trends in the area of anthropogenic emissions in the long term (see Article 4(2)(a) of the UN Climate Convention and the principle of 'differentiated responsibilities and respective capabilities' referred to above). They must also periodically communicate about the policy and the measures taken, with the objective of individually or collectively returning to their 1990 levels (Article 4(2)(b) of the UN Climate Convention).

In Article 4(3-5), the UN Climate Convention describes the obligations of the developed country parties and the other developed parties included in Annex II. The Netherlands is also one of the Annex II countries. Briefly put, these countries make financial means available to the parties that are developing countries, along with environmentally-friendly technologies and know-how. Therefore, Annex II does not comprise a group of developing countries.269.

Conference of the Parties (COP). The COP is the supreme body of the UN Climate Convention (Article 7(1) of the UN Climate Convention). The COP 'shall keep under regular review the implementation of the Convention and any related legal instruments that the Conference of the Parties may adopt, and shall make, within its mandate, the decisions necessary to promote the effective implementation of the Convention'. (Article 7(2) of the UN Climate Convention.) In addition, the COP’s powers include making recommendations (Article 7(2)(g)) and adopting regular reports on the implementation of the Convention (Article 7(2)(f)).

As is evident from Article 7(2) of the UN Climate Convention, the COP may adopt legal instruments and make other decisions. Examples of these include the Kyoto Protocol and the Paris Agreement, which are treaties.270.

Nevertheless, in general COP decisions are not legally binding271., and in that sense they are not a source of international law. They are, however, regularly deemed to be 'soft law' as referred to in section 2.31 of this opinion.272.

In these proceedings, various COP decisions have been pointed out in which direct or indirect reference is made to a reduction target for Annex I countries of 25-40% in 2020 as compared to 1990. These decisions are mentioned below in section 4.13 et seq. It is not in dispute that these COP decisions are not decisions or provisions that have direct, binding effect.273.

To the extent still relevant,274.in referring to COP decisions a distinction can be made between:

- CP decisions: 'Decisions adopted by the Conference of the Parties'; and

- CMP decisions: 'Decisions adopted by the Conference of the Parties serving as the meeting of the Parties to the Kyoto Protocol'.

An overview of a few of the COPs (climate conferences) relevant to these proceedings is given below.

COP-3 was held in Kyoto, Japan, in 1997, resulting in the Kyoto Protocol.275.In it, various, but not all,276.Annex I countries mutually agreed on specific reduction levels for the period 2008-2012 (see section 1.2(xvi)).

The ‘commitments’ under the Kyoto Protocol may be jointly satisfied; states then join forces in what is referred to as a ‘bubble’ (Articles 3 and 4 of the Kyoto Protocol). On that basis, the EU Member States jointly committed to a reduction level for the period 2008-2012.277.However, if the EU Member States were to fail to satisfy the joint obligations, individual Member States are responsible for their agreed individual obligations, according to Article 4(5) of the Kyoto Protocol.278.

COP-13 was held on Bali in 2007, at which the Bali Action Plan was created, containing agreements on mitigation, adaptation, technological collaboration and financial support (see section 1.2(xvii)).279.The preamble to the Bali Action Plan includes the following references to the IPCC's AR4 Report, discussed below at 4.39:

'Recognizing that deep cuts in global emissions will be required to achieve the ultimate objective of the Convention and emphasizing the urgency1 to address climate change as indicated in the Fourth Assessment Report of the Intergovernmental Panel on Climate Change,'

with a reference in footnote 1 to various pages of the AR4 Report:280.

'Contribution of Working Group III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Technical Summary, pages 39 and 90, and Chapter 13, page 776.'

Said page 776 contains Box 13.7 as referred to below, stating a reduction target for the Annex I countries of 25-40% in 2020 as compared to 1990.

COP-16 was held in Cancun in 2010. At this COP, the parties adopted the Cancun Agreements (see section 1.2(xviii)-(xix)).281.In their 'Cancun Pledges', the parties laid down their specific reduction targets, with the EU pledging to reduce the emission of greenhouse gases by 20% as compared to 1990 by the end of 2020. The EU explicitly offered to reduce the emission of greenhouse gases by 30% if the other developed countries, among others, committed to a similar reduction.282.

During this COP, the countries that were party to the Kyoto Protocol adopted a decision,283.which refers in its preamble to the outcome of the AR4 Report and the reduction target included therein for Annex I countries, as a group, of 25-40% in 2020 as compared to 1990:284.

'Also recognizing that the contribution of Working Group III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Climate Change 2007: Mitigation of Climate Change, indicates that achieving the lowest levels assessed by the Intergovernmental Panel on Climate Change to date and its corresponding potential damage limitation would require Annex I Parties as a group to reduce emissions in a range of 25–40 per cent below 1990 levels by 2020, through means that may be available to these Parties to reach their emission reduction targets,'

During COP-17, held in Durban in 2011, the countries that were party to the Kyoto Protocol also adopted a decision referring to a reduction percentage for the Annex I Countries of 25-40% in 2020 as compared to 1990:285.

'Aiming to ensure that aggregate emissions of greenhouse gases by Parties included in Annex I are reduced by at least 25–40 per cent below 1990 levels by 2020, noting in this regard the relevance of the review referred to in chapter V of decision 1/CP.16 to be concluded by 2015,'.

The eighteenth COP, held in Doha, Qatar in 2012, adopted the Doha Amendment (see section 1.2(xx)).286.This amendment amended Annex B of the Kyoto Protocol, but never went into force.287.Where the first version of this Annex concerned the 'first commitment period' 2008-2013, in the amendment the emission reduction levels were determined for the 'second commitment period' 2013-2020.288.For the EU, this amendment entailed EU Member States committing to a 20% reduction in 2020 as compared to 1990.

The Doha Amendment mentions a reduction percentage for the Annex I Countries of 25-40% in 2020 as compared to 1990:289.

'7. Decides that each Party included in Annex I will revisit its quantified emission limitation and reduction commitment for the second commitment period at the latest by 2014. In order to increase the ambition of its commitment, such Party may decrease the percentage inscribed in the third column of Annex B of its quantified emission limitation and reduction commitment, in line with an aggregate reduction of greenhouse gas emissions not controlled by the Montreal Protocol by Parties included in Annex I of at least 25 to 40 per cent below 1990 levels by 2020;’.

At the next COP-19, held in Warsaw in 2013, reference was made to this part of the Doha Amendment in Decision 1/CP.19, para. 4(c):

'(c) Urging each developed country Party to revisit its quantified economy-wide emission reduction target under the Convention and, if it is also a Party to the Kyoto Protocol, its quantified emission limitation or reduction commitment for the second commitment period of the Kyoto Protocol, if applicable, in accordance with decision 1/CMP.8, paragraphs 7–11;'.

At the COPs in 2014 (Lima)290.and 2015 (Paris)291.reference was made to 1/CP.19, paras. 3 and 4. Urgenda believes this is another reference to the reduction target of 25-40%.292.According to Urgenda, the COP decisions adopted after Paris no longer specifically referred to this reduction target.293.The State believes that reference to the reduction target of 25-40% was only made in the decisions of the COPs in Cancun, Durban and Doha.294.According to the Court of Appeal, this percentage was referred to in the COPs held in Bali, Cancun, Durban, Doha and Warsaw.295.

Paris Agreement.296.The Paris Agreement adopted in Paris in COP-21 in (also the Paris Climate Agreement)297.was already briefly stated in paragraph 1.2 (xxi). Briefly put, the objective of the Paris Agreement is to improve implementation of the UN Climate Convention and the objective, reinforcing the global response to the threat of climate change. In the Paris Agreement, the parties strive to achieve this by limiting the increase of the worldwide average temperature to 2°C, and by continuing to endeavour to limit the increase to 1.5°C (Article 2(1) and at a).

All of the parties are required to make an ambitious, nationally determined contribution ('NDC') to the global response to climate change, and to give notice of this contribution (Article 3). With a view to the aforementioned temperature objective, the parties are endeavouring to achieve the peak level of the emission of greenhouse gases as soon as possible. The parties also acknowledge that the parties to the agreement that are developing countries will reach this peak later (Article 4(1)). The parties are to take national mitigation measures (Article 4(2)). Each subsequent nationally determined contribution of a party must go further than its nationally determined contribution at that time and must reflect the highest possible level of ambition (Article 4(3)).

According to the Paris Agreement, all countries must contribute to limiting the emission of greenhouse gases.

Like with the UN Climate Convention, the Paris Agreement is based on a number of - largely similar - principles, including the equity and the principle of common but differentiated responsibilities and respective capabilities, in the light of different national circumstances (preamble and Article 2(2)). The parties that are developed countries must continue taking the lead by undertaking economy-wide absolute emission reduction targets.

The distinction between Annex I countries and other countries is no longer included in the Paris Agreement. Briefly put, this is based on the fact that some non-Annex I countries, such as China, India, Brazil and Indonesia, have since developed to such an extent that they are responsible for a large part of global greenhouse gas emissions.298.The Paris Agreement does not change the UN Climate Convention, however, as a result of which the distinction between Annex I countries and other countries still exists, at least formally.299.

In the preamble to the COP decision to adopt the Paris Agreement, reference is made to the urgent need to do something about the significant gap between the reductions of greenhouse gas emissions that were pledged and those that are needed:300.

'Emphasizing with serious concern the urgent need to address the significant gap between the aggregate effect of Parties’ mitigation pledges in terms of global annual emissions of greenhouse gases by 2020 and aggregate emission pathways consistent with holding the increase in the global average temperature to well below 2 °C above pre-industrial levels and pursuing efforts to limit the temperature increase to 1.5 °C above pre-industrial levels,

Also emphasizing that enhanced pre‐2020 ambition can lay a solid foundation for enhanced post‐2020 ambition,

Stressing the urgency of accelerating the implementation of the Convention and its Kyoto Protocol in order to enhance pre-2020 ambition,'.

All this is fleshed out in this COP decision at para. 105 et seq. concerning 'Enhanced action prior to 2020', to which reference was already made in a footnote to section 4.18.

The European Union Article 191 TFEU contains the EU's environmental objectives, providing for example:

'Article 191

1. EU policy on the environment shall contribute to pursuit of the following objectives:

- preserving, protecting and improving the quality of the environment;

- protecting human health;

- prudent and rational utilisation of natural resources;

- promoting measures at international level to deal with regional or worldwide environmental problems, and in particular combating climate change.

2. EU policy on the environment shall aim at a high level of protection taking into account the diversity of situations in the various regions of the EU. It shall be based on the precautionary principle and on the principles that preventive action should be taken, that environmental damage should as a priority be rectified at source and that the polluter should pay. (…).'

As indicated, the EU has committed to a 20% reduction of greenhouse gas emissions in 2020 as compared to 1990, with a conditional offer of a 30% reduction.301.

A reduction target of 30% in 2020 is reported in the European Council's conclusions of 8/9 March 2007:302.

'30. The European Council reaffirms that absolute emission reduction commitments are the backbone of a global carbon market. Developed countries should continue to take the lead by committing to collectively reducing their emissions of greenhouse gases in the order of 30 % by 2020 compared to 1990. They should do so also with a view to collectively reducing their emissions by 60 % to 80 % by 2050 compared to 1990.'

The negotiated contribution referred to is then stated in section 4.24: a pledge of 20% and a conditional offer of 30%.

The size of the contribution was subject to previous discussions. This is evident from, for example, the EC's announcement of 10 January 2007 (COM(2007) 2 final) referred to by the District Court in para. 2.60:

'The Council has agreed that developed countries will have to continue to take the lead to reduce their emissions between 15 to 30 % by 2020. The European Parliament has proposed an EU CO2 reduction target of 30 % for 2020 and 60 to 80 % for 2050.'

In this announcement, the EC proposed to the EU (at 1):

'in the context of international negotiations the objective of 30 % reduction in greenhouse gas emissions (GHG) by developed countries by 2020 (compared to 1990 levels). This is necessary to ensure that the world stays within the 2ºC limit. Until an international agreement is concluded, and without prejudice to its position in international negotiations, the EU should already take on a firm independent commitment at this time to achieve at least a 20% reduction of GHG emissions by 2020, by means of the EU emission trading scheme (EU ETS), other climate change policies and actions in the context of the energy policy. This approach will allow the EU to demonstrate international leadership on climate issues.'

The EU's pledge of 20% in 2020 is lower than the 25-40% mentioned in AR4, as also noted, for example, in the EESC's advice of July 2008 referred to in para. 2.61 of the District Court's judgment. As explained, this was politically motivated.

By contrast, the EC's announcement of 10 January 2007, cited above in section 4.26, refers to a 'necessary' reduction target of 30% in 2020 in connection with the 2ºC target.303.Recital 6 of Directive 2009/29/EC links a reduction of 30% in 2020 in so many words to scientific insights when referring to the objective:

'to achieving an overall reduction of more than 20 %, in particular in view of the European Council’s objective of a 30 % reduction by 2020 which is considered scientifically necessary to avoid dangerous climate change.'

The EU adopted various directives and decisions for the implementation of its environmental policy. Reference can be made in particular to the ETS Directive already briefly mentioned in section 1.2 at (xxiv)-(xxv) and to what is known as the Effort Sharing Decision.

ETS Directive The Directive concerning a scheme for greenhouse gas emission allowance trading,304.known as the ETS Directive, is from 2003 and has since been amended by, for example, Directive 2009/29 EC305.and by Directive 2018/410.306.

The ETS only applies to large, energy-intensive companies like large power plants and refineries.307.Companies in the EU that are subject to the ETS system may only emit greenhouse gases if they surrender emission allowances. These emission allowances may be bought, sold or retained.308.Certain industrial sectors are awarded certain quantities of emission allowances in order to prevent 'carbon leakage', for example.309.As of 2019, a Market Stability Reserve (MSR) will withdraw certain quantities of emissions from the market, temporarily or otherwise.310.

According to Directive 2009/29 EC, the total volume of greenhouse gases which ETS companies may emit in the period 2013-2020 decreases annually until, in 2020, a 21% reduction is achieved in comparison to the year 2005.311.Directive 2018/410 tightens the ETS system, including by making it possible to cancel certain emission allowances.312.

Effort Sharing Decision. Decision no. 406/2009/EC313., states that with a view to regulation of emissions in the non-ETS sectors, developed countries, including the EU Member States, should continue to take the lead by committing to collectively reducing their emissions of greenhouse gases in the order of 30% by 2020 compared to 1990 However, the European Council decided that until a global and comprehensive agreement for the period after 2012 is concluded, and without prejudice to its position in international negotiations, the Community makes a firm independent commitment to achieve at least a 20% reduction of greenhouse gas emissions by 2020 compared to 1990.314.Based on the Effort Sharing Decision315., it was determined that was within the EU, for non-ETS sectors, the reduction target of 20% in 2020 means that the Netherlands will have to achieve a emissions reduction of 16% as compared to emissions in 2005.

The Netherlands. The government’s concern is to keep the country habitable and to protect and improve the environment.316.The ETS Directive has been translated into Dutch legislation. The Climate Act recently took effect (see paras. 1.6-1.7). The Netherlands is a party to the UN Climate Convention, the Kyoto Protocol and the Paris Agreement.

As mentioned earlier (section 1.2 at (xxvii)-(xxix)), the Netherlands applied the premise of a reduction target for 2020 of 30% as compared to 1990. This objective was adjusted in 2011 to a reduction within the EU context of 20% in 2020, at least 40% in 2030 and 80-95% in 2050, always as compared to 1990.317.The Climate Act envisages a reduction of 49% in 2030 and 95% in 2050.

IPCC reports AR4 and AR5 318.

In cassation, a major part of the discussions pertain to the meaning of the IPCC Reports AR4 and AR5. The IPCC was already mentioned in section 1.2 at (x)-(xi). Below, we will discuss (i) the IPCC's working method, and the two Assessment Reports relevant in these proceedings: (ii) AR4 from 2007 and (iii) AR5 from 2013/14.

IPCC's working method. The IPCC's work is divided over three Working Groups. Working Group I studies existing scientific knowledge in respect of the climate system and the climate change. Working Group II is charged with studying the consequences of climate change on the environment, the economy and society. Working Group III discusses the possible strategies in response to these changes. The Working Groups perform their work based on the 'Principles Governing IPCC Work' and the accompanying 'Procedures for the preparation, review, acceptance, adoption, approval and publication of IPCC reports'.319.The procedures320.address matters including dealing with uncertainties in the Assessment Reports.321.

Each part of an Assessment Report by one of the three Working Groups comprises (i) a Summary for Policymakers, (ii) the actual chapters of the report, and possibly (iii) a Technical Summary. An Assessment Report also contains a Synthesis Report, which summarises the three reports made by the three Working Groups.

The various parts of an Assessment Report are subject to 'different levels of formal endorsement', to wit: 'acceptance', 'adoption', or 'approval'.322.In descending order of the seriousness of the procedure, these variations entail the following:323.

- Approval: 'that the material has been subject to detailed, line by line discussion and agreement.';

- Adoption: 'a process of endorsement section by section (and not line by line) used for the longer report of the Synthesis Report as described in section 4.4 and for Overview Chapters of Methodology Reports.'; and

- Acceptance: 'that the material has not been subject to line by line discussion and agreement, but nevertheless presents a comprehensive, objective and balanced view of the subject matter.'

The following levels of approval apply to the various parts of an Assessment Report:324.

'A. In general, IPCC Reports are accepted by the appropriate Working Group. Reports prepared by the Task Force on National Greenhouse Gas Inventories are accepted by the Panel. Summaries for Policymakers are approved by the appropriate Working Groups (Section 4.2) and subsequently accepted by the Panel (Section 4.4). Overview chapters of Methodology Reports are adopted, section by section, by the appropriate Working Group or in case of reports prepared by the Task Force on National Greenhouse Gas Inventories by the Panel (Section 4.4). In the case of the Synthesis Report the Panel adopts the underlying Report, section by section, and approves the Summary for Policymakers. The definition of the terms 'acceptance', 'adoption' and 'approval' will be included in the IPCC published Reports (Section 4.6).

B. Technical Papers are not accepted, approved or adopted by the Working Groups or the Panel but are finalised in consultation with the Bureau, which will function in the role of an Editorial Board (Section 5).

C. Supporting Materials are not accepted, approved or adopted (Section 6).'

Fourth Assessment Report (AR4).325.In the Synthesis Report AR4, the following is reported regarding the consequences of a temperature increase of 2°C above the pre-industrial level:326.

'Confidence has increased that a 1 to 2°C increase in global mean temperature above 1990 levels (about 1.5 to 2.5°C above pre-industrial) poses significant risks to many unique and threatened systems including many biodiversity hotspots.'

Table 3.10 of the report by Working Group III offers insight into the possibilities for not exceeding the 2°C limit.327.A summary is given of the connection between various emissions scenarios, stabilisation objectives and temperature changes. Account was also taken of climate sensitivity of likely (>66%) 2-4.5°C. The 'climate sensitivity' reflects the extent to which the temperature is expected to respond to twice the greenhouse gas concentration in the atmosphere. The report goes on to depart from a 'best estimate' climate sensitivity of 3°C.

According to the Report, departing from a climate sensitivity of 3°C, a temperature increase of no more than 2°C can only be achieved if the concentration of greenhouse gases in the atmosphere stabliseds at around 450 ppm:328.

'This ‘best estimate’ assumption shows that the most stringent (category I) scenarios could limit global mean temperature increases to 2°C–2.4°C above pre-industrial levels, at equilibrium, requiring emissions to peak within 10 years. Similarly, limiting temperature increases to 2°C above pre-industrial levels can only be reached at the lowest end of the concentration interval found in the scenarios of category I (i.e. about 450 ppmv CO2-eq using ‘best estimate’ assumptions). By comparison, using the same ‘best estimate’ assumptions, category II scenarios could limit the increase to 2.8°C–3.2°C above pre-industrial levels at equilibrium, requiring emissions to peak within the next 25 years, whilst category IV scenarios could limit the increase to 3.2°C–4°C above pre-industrial at equilibrium requiring emissions to peak within the next 55 years. Note that Table 3.10 category IV scenarios could result in temperature increases as high as 6.1°C above pre-industrial levels, when the likely range for the value of climate sensitivity is taken into account.'

Chapter 13 of Working Group III's report (p. 776), reduction targets for Annex I countries, among others, with a 450 ppm scenario are shown in Box 13.7:329.

The Technical Summary of Working Group III's contribution to AR4/2007 (p. 90) also reports:

'Under most equity interpretations, developed countries as a group would need to reduce their emissions significantly by 2020 (10–40% below 1990 levels) and to still lower levels by 2050 (40–95% below 1990 levels) for low to medium stabilization levels (450–550ppm CO2-eq) (see also Chapter 3).'

Fifth Assessment Report (AR5).330.AR5 is the IPCC's most recent Assessment Report. In that report, the IPCC's Working Group III concludes that if the concentration of greenhouse gases in the atmosphere stabilises in 2100 at about 450 ppm, there is a chance of more than 66% that the increase in the global temperature will remain below 2°C. In order to arrive at a concentration level of 450 ppm in 2100, global greenhouse gas emissions in 2050 must be about 40%-70% lower than those in 2010. In 2100, the total emissions must be reduced to nil, or to even less than in the year of comparison, according to the District Court while referring to the Summary for Policymakers in the report from Working Group III (the table mentioned below reports a bandwidth of -188 to -78%; also see paras. 4.147-4.149). Stabilisation at about 500 ppm in 2100 offers a chance of more than 50% - more likely than not - of realising the 2ºC target.331.

The foregoing is also evident from the following table in the AR5 Synthesis Report (p. 83):

The AR5 Synthesis Report describes an emission pathway - Representative Concentration Pathway or RCP - to certain concentrations of greenhouse gases in the atmosphere with which the realisation of the 2ºC target is 'likely', meaning a chance of more than 66%. This is the 'RCP 2.6' scenario, as reported in the above Table 3.1 with a greenhouse gas concentration of 450 (430-480) ppm in 2100. RCP 2.6 and other RCPs are shown in the figure below, Figure 3.2 from the AR5 Synthesis Report (p. 82):

The IPCC Working Group III expects that absent additional reduction measures, Earth's temperature in 2100 will have increased by 3.7 to 4.8°C and the level of 450 ppm will have been exceeded in 2030:332.

'Without additional efforts to reduce GHG emissions beyond those in place today, emissions growth is expected to persist driven by growth in global population and economic activities. Baseline scenarios, those without additional mitigation, result in global mean surface temperature increases in 2100 from 3.7 °C to 4.8 °C compared to pre-industrial levels (…) (median values; the range is 2.5 °C to 7.8 °C when including climate uncertainty (…) (high confidence). The emission scenarios collected for this assessment represent full radiative forcing including GHGs, tropospheric ozone, aerosols and albedo change. Baseline scenarios (scenarios without explicit additional efforts to constrain emissions) exceed 450 parts per million (ppm) CO2eq by 2030 and reach CO2eq concentration levels between 750 and more than 1300 ppm CO2eq by 2100. This is similar to the range in atmospheric concentration levels between the RCP 6.0 and RCP 8.5 pathways in 2100. For comparison, the CO2eq concentration in 2011 is estimated to be 430 ppm (uncertainty range 340 – 520 ppm).'

As mentioned earlier in section 1.2 at (xxii)-(xxiii), the UNEP has issued the same warning. In its Annual Report 2017, UNEP notes that if the 'emissions gap' is not overtaken by 2030, it is highly unlikely that the 2ºC target will still be achievable. Even if the reduction targets on which the Paris Agreement is based were to be implemented in full, 80% of the carbon budget still available within the context of the 2ºC target will have been consumed by 2030. Departing a 1.5°C target, the carbon budget will have been completely exhausted by then. This was why even more ambitious reduction targets are needed for 2020, according to the UNEP.

The facts; 2ºC target, carbon budget and emission reductions

Below, we will summarise the key facts established by the District Court and the Court of Appeal in respect of the necessity of reducing greenhouse gas emissions. Continuing along that line, we will then discuss the concept of the carbon budget and its effect on the speed at which the emission of greenhouse gases must be reduced (section 4.55). First, however, we would note the following regarding the establishment of facts in civil proceedings.

The nature of the establishment of facts. In these proceedings, the State and Urgenda have extensively discussed what they believe to be the relevant facts. Although they differ in terms of their opinion about the meaning that can be attached to the facts in respect of the admissibility of Urgenda's claim, the State and Urgenda largely concur on the relevant facts as such. This means that in principle, the civil court must depart from those facts.333.

On that basis, therefore, the District Court established the relevant facts for the assessment of Urgenda's claim.334.Criticism is heard in the literature, however, of parts of facts established by the District Court - because it is 'doubtful', according to one author, 'that what the parties acknowledge reliably reflects the current state of the art'.335.This criticism, which may remain moot, was not relevant on appeal, as the facts established by the District Court were not put to a discussion on appeal. This is why the Court of Appeal was required to depart from those facts.336.As noted earlier (section 1.35), the Supreme Court does not conduct a new investigation of the facts in cassation.337.

In these proceedings, therefore, it has been asserted without discussion that a connection exists between human activity and global warming, for example, and that consensus exists regarding the 2ºC target, and that the emission of greenhouse gases must be limited.

The State did point out certain uncertainties identified by the IPCC in respect of climate change and their consequences.338.The Court of Appeal took such uncertainties into account in its assessment of the relevant facts.339.

The key facts340.Below, we will once again summarise the key facts; also see section 1.2(i) et seq. as introduction to the in-depth discussion that will follow.

(i) Greenhouse gases CO2 (carbon dioxide) is the most important greenhouse gas. Other greenhouse gases, such as methane, laughing gas, and fluorinated gases, may have a larger greenhouse effect - expressed as Global Warming Potential or GWP - albeit for a shorter period than CO2. In that sense, the Court of Appeal's opinion at 3.3 is apparently intended to mean that other greenhouse gases have a lower global warming potential than CO2 and degrade at another speed. This opinion is not disputed in cassation.

The concentration of greenhouse gases in the atmosphere is expressed using the unit parts per million, abbreviated as ppm. The abbreviation 'ppm CO2-eq' (parts per million CO2 equivalent) is used to indicate the concentration of all greenhouse gases combined, with the amount of greenhouse gases other than CO2 being converted into CO2 in terms of warming effect.

(ii) The greenhouse effect and climate change There is a direct, linear connection between greenhouse gas emissions caused by humans, which are partly caused by the burning of fossil fuels, and the warming of the planet. Once emitted, CO2 remains in the atmosphere for hundreds of years, if not longer.

The planet Earth is 1.1ºC warmer today than in the pre-industrial era. Global warming amounted to approx. 0.4ºC between 1850 and 1980. Since then, global warming has continued for another 0.7ºC to the current level of 1.1ºC; this global warming is expected to accelerate even more, in particular because greenhouse gas emissions only realise their full warming potential after thirty to forty years.

(iii) The 2ºC target Climate scientists and the global community concur that global warming must be kept amply below 2ºC, while a 'safe' temperature increase should not be more than 1.5ºC, all as compared to the pre-industrial level. Global warming of more than 2ºC in comparison to the pre-industrial era would cause, for example: flooding as a result of sea level rise; heat stress as a result of more intense and longer-lasting heat waves, increases in respiratory ailments associated with deteriorating air quality, droughts (with devastating forest fires), increased spread of infectious diseases, severe flooding as a result of torrential rainfall, and disruptions in the production of food and the supply of drinking water. Ecosystems, flora and fauna will be eroded and there will be losses in terms of biodiversity. An inadequate climate policy will result in the second half of this century to hundreds of thousands of victims in Western Europe alone.341.

As global warming continues, not only the seriousness of the consequences will increase. The accumulation of greenhouse gases in the atmosphere could lead to the tipping point of the process of climate change, resulting in an abrupt climate change for which neither man nor nature can be adequately prepared. The risk of such a tipping point occurring increases at a steeping rate when the temperature increases between 1-2ºC.342.

(iv) Realising the 2ºC objective Global greenhouse gas emissions are still increasing. The emission of greenhouse gases remains high in the Netherlands, as well. Chances of reaching the 1.5ºC target are now very slim. In any event, limiting global warming to less than 2ºC will take enormous effort.

(v) The carbon budget In the realm of climate science, as well as in the global community, long ago a consensus was reached entailing that the average temperature of the planet may not increase by more than 2ºC in comparison to the average temperature during the pre-industrial era. If the concentration of greenhouse gases in the atmosphere has not risen above 450 ppm by the year 2100, there is a reasonable chance that this objective will be realised. Limiting global warming to no more than 1.5ºC - which is the objective of the Paris Agreement - will require a significant reduction in the global concentration of greenhouse gases, to less than 430 ppm. The current concentration in 2018 was about 401 ppm. This means that the concentration of greenhouse gases in the atmosphere may increase only to a very limited degree. The longer it takes to realise the necessary reduction in emissions, the larger the total quantity of greenhouse gas emissions, and the earlier the carbon budget will be exhausted.

(vi) The ultimate goal for 2100 and the reduction targets for 2050 and 2030 The ultimate goal is clear and not in dispute. Global greenhouse gas emissions must be brought to halt by 2100. The parties also have no quarrel as to the necessary interim reduction of 80-95% in 2050 as compared to 1990, and Urgenda endorses the government's proposed reduction target of 49% in 2030 as compared to 1990.

Below, we will discuss the connection between the 2ºC target, the carbon budget and the speed of greenhouse emission reductions in more detail based on the data and figures applied as premise by the District Court and the Court of Appeal. Those form the basis for the Court of Appeal's summary considerations reflected above in section 4.54.

The 2ºC target and the carbon budget What firstly follows from the facts as established is the importance of realising the 2ºC target. The facts also show that with a view to the 2ºC target, the concentration of greenhouse gases in the atmosphere may only increase to a limited degree, to wit to approx. 450 ppm. Given the current concentration of greenhouse gases in the atmosphere (2018: 401 ppm), there is only limited room for the emission of greenhouse gases before a concentration of 450 ppm is reached. This room is called the carbon budget.343.The carbon budget limits the total of worldwide greenhouse gas emissions. Each ton of emissions reduces the remaining budget. The longer it takes to realise the necessary reduction in emissions, the larger the total quantity of greenhouse gas emissions, and - therefore - the earlier the carbon budget will be exhausted (see 4.54(v) above).

The carbon budget and the speed of the reductions Therefore, it follows from the facts that the speed of the emission reductions is crucial. The earlier reductions commence, the more time before the remaining budget is exhausted. Conversely, the later a reduction is realised, the less time before the budget is exhausted. This means that the sooner reductions commence, the more time left for taking measures to combat climate change and its consequences.

The Court of Appeal refers to para. 4.32 of the District Court's judgment in this regard. The District Court also devoted attention to the carbon budget in para. 2.32 of its judgment. Those opinions by the District Court are included in the established facts from which the Court of Appeal departed. First we will discuss para. 2.32 and then para. 4.32 of the District Court's judgment.

In para. 2.32 of its judgment, the District Court referred to the UNEP Emissions Gap Report 2014. In that report, the question of when the world must be greenhouse gas neutral given the 2ºC target is discussed. Greenhouse gas neutral means: a net result of anthropogenic positive and negative greenhouse gas emission of zero.344.

Here, positive emission refers to the emission of greenhouse gases due to human activity. Negative emission refers to greenhouse gases being removed from the atmosphere by means of suitable technology.345.This is sometimes referred to as Carbon Dioxide Removal (CDR) through means of Negative Emission Technologies (NET).346.One example of this is BECCS: the production of energy through the combustion of biomass in which greenhouse gases are stored, known as bio-energy (BE), followed by the capture and storage of the greenhouse gases released during the combustion (carbon capture and storage: CCS).347.For the record, CCS can also be used with processes in the energy or other sectors in which oil, coal or gas is combusted, but this does not result in negative greenhouse gas emissions.

Negative emissions play a part in scenarios in which the concentration of greenhouse gases in the atmosphere is temporarily higher than the concentration necessary in order to realise the 2ºC target, called 'overshoot'.348.

The UNEP Report referred to by the District Court reflects the foregoing in this figure, departing from a carbon budget in 2012 of 1000 giga tons of greenhouse gases for the 2ºC target.

The top image of the figure in section 4.59 shows what happens if emissions are higher for the time being, and therefore if emissions are reduced at a slower rate. There are two main effects. Firstly, the remaining carbon budget is exhausted faster. As a result, the tipping point at which no emissions – positive emissions – are permitted is reached earlier. This means that intervention in the near and further future will have to be more far-reaching in order to still reach zero emissions quickly, from a relatively high level of emissions. This will probably be more difficult for society than a more gradual reduction of emissions.349.Secondly, more negative emissions will be needed in the future. This means that the technologies necessary for this will be relied on more heavily.350.

The bottom part of the figure in section 4.59 shows what happens if emissions are lower earlier, and therefore if emissions are reduced at a faster rate. In that event, the remaining carbon budget is exhausted more slowly. As a result, the tipping point at which no emissions - positive emissions - are permitted is reached later. There is more time to achieve the 2ºC target. Lower negative emissions will be needed, and the capture and storage of greenhouse gases can commence later. This means that there will be more time before reliance on the technologies necessary for the capture and storage of greenhouse gases is needed.

It therefore follows from the fact that only a limited carbon budget remains for achieving the 2ºC target that reducing emissions faster and more will improve the chance of realising that target. In this regard the Court of Appeal refers in para. 44 to para. 4.32 of the District Court's judgment. There, three Urgenda figures are presented, the first of which is shown below. The first figure illustrates that not only the reduction targets for a certain year - such as 49% lower reductions in 2030 as compared to 1990 - but also the speed for realising that reduction target in that year must be taken into account (referred to as reduction pathways [reductie routes] in the figure shown below). The later emission reductions commence, the faster the carbon budget is exhausted. In order to prevent this, later reductions would need to be accelerated in order to make up for the 'backlog' incurred.

Figure 1(Urgenda)

Following the pathway entitled 'Fixed annual reduction percentage' [vast jaarlijks reductiepercentage], the red (lower) part reflects the quantity of greenhouse gas emissions and thus the part of the carbon budget consumed. Following the pathway entitled 'Fixed annual reduction quantity' [vaste jaarlijkse reductiehoeveelheid], this consumption is collectively comprised of the red section and the blue (middle) section. Following the pathway that Urgenda calls 'Postponed reduction' [uitgestelde reductie],351.the consumption is collectively comprised of the red section, the blue section and the (top) grey section.

The other two Urgenda figures referred to by the Court of Appeal in para. 44 reflect the details of Urgenda's Figure 1. They illustrate that the EU is following the scenario called 'Postponed reduction' by Urgenda, based on the expected EU-wide reduction of 27% in 2020 and the EU reduction targets of 40% in 2030 and 80-95% in 2050. See para. 4.32 of the District Court's judgment for these figures.

The UNEP and Urgenda figures presented above in 4.59 and 4.63 only show the mechanisms described - meaning the mechanism in which postponing the reduction of greenhouse gases leads to faster consumption of the carbon budget remaining for realisation of the 2ºC target - even when the reduction target for a certain year in the future, such as 2030 or 2050, remains the same.

The figures presented above do not show whether postponing reductions will already be problematic in the short term, or whether there is still so much room in the remaining carbon budget that postponing reductions will only become problematic if the reductions do not take place in the medium to long term. The following facts have been established in these proceedings with regard to the latter.

(i) Global greenhouse gas emissions are still increasing. The current (meaning: 2018) concentration of greenhouse gases is about 401 ppm, as a result of which the concentration may only increase to a limited extent.352.

(ii) The IPCC353.expects in AR5 that absent reduction measures, Earth's temperature will have increased by 3.7 to 4.8°C in 2100 and the level of 450 ppm will have been exceeded in 2030.354.The IPCC355.states in AR5 that '(…) Delaying mitigation efforts beyond those in place today through 2030 is estimated to substantially increase the difficulty of transition to low-longer-term emissions levels and narrow the range of options consistent with maintaining temperature change below 2ºC relative to pre-industrial levels.'356.

(iii) The UNEP357.concludes that with a view to achieving the 2°C target, there is an ‘emissions gap’.358.UNEP's 2017 Annual Report says that in light of the Paris Agreement, increased pre-2020 mitigation measures are more urgent than ever. The UNEP also remarks that if the emissions gap is not bridged by 2030, achieving the 2°C target is extremely unlikely. Even if the reduction targets on which the Paris Agreement is based were to be implemented in full, 80% of the carbon budget still available within the context of the 2ºC target will have been consumed by 2030. Departing a 1.5°C target, the carbon budget will have been completely exhausted by then. This was why even more ambitious reduction targets are needed for 2020, according to the UNEP359.. The UNEP360.concludes that 'later action scenario’s361. may not be feasible in practise and, as a result, temperature targets could be missed' and that 'later-action scenario’s pose greater risks of climate impacts'.362.

(iv) In its report of 18 November 2016 further to the Paris Agreement, the Netherlands Environmental Assessment Agency (Planbureau voor de leefomgeving - PBL)363.describes the limited carbon budget and the need for a stringent climate policy throughout the world: a policy that must go much further than the existing policy of the countries involved. According to the PBL, the Netherlands’ policy must be tightened in the short term to bring it in line with the Paris Agreement (with regard to the Paris targets of 2°C and 1.5°C).364.

In addition, we would note that the speed of the consumption of the carbon budget is also illustrated by the following figure from a publication in Nature (2017), to which Urgenda referred.365.

Lastly, we would note that the feasibility of realising the 2°C target is also dependent on the use of technologies for the large-scale capture and storage of greenhouse gases in the future. As discussed earlier, reliance on such technologies in order to achieve the necessary negative emissions will increase as the commencement of the reduction of greenhouse gas emissions is postponed. The Court of Appeal pointed out that in 87% of the scenarios included in RCP2.6 from AR5 include premises that are related to negative emissions.366.

The Court of Appeal's assessment of the facts

Based on the facts discussed above, the Court of Appeal held firstly that it is appropriate to speak of 'a real threat of a dangerous climate change' (para. 45).

The Court of Appeal went on to conclude that this threat 'result[s] in the serious risk that the current generation of citizens will be confronted with loss of life and/or a disruption of family life'. The State's complaints against this part of para. 45 were already discussed (section 3.2 et seq.).

The Court of Appeal subsequently explored the question that now has central focus: whether the State has acted unlawfully in respect of Urgenda by not reducing the emissions by at least 25% as at the end of 2020, despite the aforementioned real threats of danger (para. 46).

The Court of Appeal's opinion, already briefly summarised at 1.29, shows that it has assessed whether the threat of a dangerous climate change obliges the State to take precautionary measures in the form of reducing the emission of greenhouse gases in the Netherlands. Although the issue in this case can be considered unique, the courts are familiar with this form of assessment of situations involving dangers in itself (in general in that regard, see Chapter 2 of this opinion).

Below, we will discuss the individual steps taken by the Court of Appeal in its assessment of the situation. In doing so, we will suffice with the essence of the Court of Appeal's reasoning. The details of that reasoning will be discussed later, with parts 4-8 of the State's ground for cassation. We will not adhere to the sequence used by the Court of Appeal for its opinions. Some of the steps could be reflected in a different order, as the Court of Appeal has done, without detracting from the reasoning itself. We have made a distinction between the following steps.

(i) There is a real threat of a dangerous climate change This fact (see para. 45) is the point of departure for the reasoning about the State's duty of care. To counter this danger, the 2ºC target with the corresponding concentration level of 450 ppm and therefore a certain carbon budget applies (para. 44). There is no dispute about the reduction targets for 2050 (80%-95%) and 2030 (49%) (para. 46).

(ii) In the short term – up to the end of 2020 – more must be done to reduce emissions. See the conclusion in para. 71 and para. 47 on which it is based. As mentioned above, if no reduction measures are taken the IPCC expects the level of 450 ppm to have been exceeded by 2030 and according to UNEP it is highly unlikely that the 2ºC target can still be realised if the emissions gap has not been closed by 2030. In para. 47, the Court of Appeal ruled that this climatologically established need for greater reductions than at this time also applies to the situation in the Netherlands in 2020 with a view to achieving the reduction targets in 2030 and beyond. In the first place, the Court takes as a point of departure:

'47. (…) that the emission of all greenhouse gases combined in the Netherlands had dropped by 13%, relative to 1990, in 2017. Even if the new calculation method was not used for this (see para. 21 of this judgment),367.a significant effort will have to be made between now and 2030 to reach the 49% target in 2030; much more efforts than the limited efforts the Netherlands has undertaken so far. (…)'

The Court of Appeal then referred to the consumption of the carbon budget in the period 2020 to 2030:

'(…) It is also an established fact that it is desirable to start the reduction efforts at as early a stage as possible in order to limit the total emissions in this period. Delaying the reduction will lead to greater risks for the climate. A delay would, after all, allow greenhouse gas emissions to continue in the meantime; greenhouse gases which linger in the atmosphere for a very long time and further contribute to global warming. In that context, the Court would like to point out to the warnings issued by the UNEP, cited in paras. 2.29 through to 2.31 of the judgment. See also the report of the PBL of 9 October 2017 (Exhibit 77 of the State) p. 60, where the PBL remarks that achieving the climate targets of the Paris Agreement not necessarily concerns achieving a low emission level in 2050, but rather and particularly achieving low cumulative emissions, considering the fact that each megaton of CO2 which is emitted into the atmosphere in the short term contributes to global warming. (…)'

Lastly, the Court of Appeal referred to the (linear) reduction pathway used by the State for the 2050 and 2030 reduction targets and the (non-linear) reduction pathway used by the State for the 2020 reduction target:

'(…) An even distribution of reduction efforts over the period up to 2030 would mean that the State should achieve a substantially higher reduction in 2020 than 20%. An even distribution is also the starting point of the State for its reduction target of 49% by 2030, which has been derived in a linear fashion from the 95% target for 2050. If extrapolated to the present, this would result in a 28% reduction by 2020, as confirmed by the State in answering the Court’s questions.''

This last consideration shows that, with a view to the 2ºC target, the State started from the reduction target of 80%-95% by 2050, that it linearly infers from this the reduction target for 2030 (49%), but that it has set a less far-reaching target for 2020, i.e. (not-linearly 28% but) 20% at EU level (we will not reiterate that this target is broken down into the targets referred to in paras. 4.30-4.31 for the ETS sector and non-ETS sector).

(iii) Postponement is irresponsible. Postponing reductions or higher reductions will lead to greater risks for the climate (paras. 47 and 52). The Court of Appeal held that, as there are clear indications now that the current measures will be insufficient to prevent dangerous climate change, measures that are safe, or at least as safe as possible, should be chosen, also on the basis of the precautionary principle (para. 73).

(iv) In particular, it is not possible to wait until 2030. The State has argued that, according to AR5, the 2ºC target can still be achieved if certain reduction targets are achieved from 2030 onwards. The Court of Appeal has rejected this position: targets for 2030 and beyond do not take away from the fact that a dangerous situation is imminent, which requires interventions being taken now (para. 71). In particular, the Court of Appeal ruled that the State cannot rely on the RCP2.6 scenario from AR5 because this scenario is based mainly (87%) on so-called overshoot scenarios with negative emissions (para. 12). The possibility of removing (sufficient) greenhouse gas from the atmosphere in the future with certain techniques is highly uncertain and, as things stand at present, climate scenarios based on such techniques are not very realistic, according to the Court of Appeal (para. 49).

(v) Emissions must be reduced by at least 25% by 2020. The Court of Appeal has specified its finding that more must be done in the short term to reduce emissions: by the end of 2020, emissions must be at least 25% lower than in 1990. Urgenda claims an emission reduction in 2020 of at least 25% compared to 1990, so it is up to the Court of Appeal to render an opinion on that (paras. 3.9 and 46). Achieving the 2ºC target will require a 25%-40% reduction in emissions by 2020 (para. 49). This emerges from AR4 (para. 48), is confirmed by the references to it in the various COP decisions (para. 51) and has not been overtaken by AR5 (para. 49). The 450 scenario and the resulting need for a 25%-40% reduction in emissions by 2020 are not based on excessively pessimistic assumptions (para. 50) and should be considered as a minimum (para. 73). This reduction obligation is in line with the State’s duty of care (paras. 53 and 73). For many years, the Dutch reduction target for 2020 was 30% compared to 1990 and it has been lowered to 20% at EU level without any climatological substantiation being provided (paras. 52 and 72).

(vi) The State’s counterarguments do not hold. See paras. 54-76. This includes the question of whether the Netherlands can be held individually responsible for its share, which on a global scale is minor, of greenhouse gas emissions and the State’s reliance on its discretion.

In the literature, the question has been raised as to how the courts can determine precisely that the Dutch reduction of greenhouse gases must be (at least) 25% by 2020. It should be borne in mind that, in light of the applicable rules of law, the court368.must (i) rule on the admissibility of a claim submitted to it and the points of contention involved, such (ii) on the basis of the facts established and proven in the proceedings.369.

With regard to the point of contention in this case, the court was not asked to determine in abstract terms what reduction percentage should be pursued by the Netherlands in which year. For example, it has not been submitted to the court as to whether emission reductions in 2020 should be 24%, 25% or 26%. Nor did the debate address the question of what the reductions should be in 2019 or 2021.370.

In this case, the court must ultimately decide on Urgenda’s claim that the reduction in 2020 should be at least 25%.371.It is therefore only about 2020 and only about the percentage of 25% or at least 25%. The court must assess whether sufficient facts and arguments have been presented to prove the need for that claimed reduction.

On the basis of scientific reports, the Court of Appeal ruled that in the short term more must be done to reduce emissions given the real threat of dangerous climate change. This brings the year 2020 into the picture. The Court of Appeal then had to assess whether the reduction in that year should be at least 25%, as Urgenda claims. No calculation model has been submitted to the Court of Appeal, if such a model could have even been submitted, from which it could be easily deduced how much more emissions should be reduced by 2020 than the 20% target set by the State at EU level. The Court of Appeal did have other information at its disposal.

From the available information – in particular information from IPCC AR4 and the references to it in COP decisions – the Court of Appeal concluded that a reduction of least 25% is indeed necessary to respond to the real threat of dangerous climate change. In this regard, the Court of Appeal considered its assessment of various risks, such as (i) the extent to which, with these reductions, the 450 ppm scenario offers ‘certainty’ to achieve the 2ºC target (‘a reasonable chance’ or ‘no more than a 50% chance’);372.(ii) the extent to which the ordered reduction of 25% by 2020 helps to avert the threat (‘high plausibility’);373.and (iii) the extent to which uncertainty about the State's ability to achieve a 25% reduction by 2020 is acceptable (not acceptable).374.The Court of Appeal ruled that the Netherlands must make an individual contribution to the prevention of dangerous climate change, even if the Netherlands cannot solve the climate problem on its own.375.

Summary of the State’s complaints in grounds for cassation 4-8

The State has lodged a large number of complaints against the Court of Appeal’s opinion expressed in paras. 4.72 et seq. In grounds for cassation 4 through 8, each of which consists of several subgrounds, the State directs complaints against (parts of) paras. 12, 15, 48, 49 and 62 (ground for cassation 4), paras. 12 and 50 through 53 (ground for cassation 5), para. 47 (ground for cassation 6), paras. 26, 60 and 62 (ground for cassation 7) and paras. 47 and 53 through 76 (ground for cassation 8).

The State essentially argues the following in grounds for cassation 4-8.376.The State is not legally bound to a reduction target of 25% by 2020. This reduction target is not a standard agreed upon by the State or an internationally accepted standard. However, the State is bound by a 20% reduction by 2020 at international and European level; this percentage will be amply met at EU level (i.e. 26% to 27%). The Court of Appeal should have taken this into account.

The 25% reduction target by 2020 is not necessary in a factual sense for the achievement of the 2ºC target. This necessity does not follow from the IPCC reports. The ordered additional reduction by the Netherlands in 2020 has no measurable effect on the global temperature increase.

Moreover, the reduction target of 25% by 2020 was once proposed as a target for a group of rich countries (the so-called Annex I countries to which the Netherlands belongs), but not as a target for an individual country such as the Netherlands. The Netherlands alone cannot solve the global climate problem.

It is up to the State to decide which reduction pathway to follow. The Court of Appeal is crossing the discretion afforded to the State.

We will discuss the complaints in grounds for cassation 4-8 below in as thematic a fashion as possible.377.In delineating the various topics, we have identified three related themes, namely the need to reduce emissions, the individual responsibility of the Netherlands, and the effects of the order.

We will first of all discuss the complaints that challenge the need for a reduction of at least 25% by 2020 as such. This concerns the following points (paras. 4.89 et seq.).

(i) The legal nature of the reduction targets for 2020. It is discussed here whether the Court of Appeal assumed that the reduction target of 25%-40% by 2020 was laid down specifically in a legally binding agreement or standard and, if not, whether the Court of Appeal was allowed to assign reflex effect to that reduction target in specifying the State's duty of care. Also discussed is whether the reduction target set at EU level precludes the assignment of reflex effect and whether the Court of Appeal should have requested the ECJ for a preliminary ruling on the matter. This is addressed in grounds for cassation 4.8, 5.4 and 5.6.

(ii) The significance of the reduction target of 25%-40% by 2020 from AR4 for Annex I countries. The reduction order is based on an opinion on the need for further reductions in greenhouse gas emissions. If the Court of Appeal did not assume that the reduction target of 25%-40% by 2020 was specifically laid down in a legally binding agreement or standard, the question that arises is why significance has been attributed to the reduction target of 25%-40% by 2020 mentioned in AR4, which has been referred to in later COP decisions. This is addressed in grounds for cassation 4.1 and 5.4.378.

(iii) This raises the question of whether this target has now been overtaken by AR5 or because the distinction between Annex I countries and other countries is outdated. This is addressed in grounds for cassation 4.2, 4.5, 4.6, 4.7, 5.2 and 5.4.

(iv) Another question that arises is whether further emission reductions in 2020 would be necessary if their postponement were to be offset by an acceleration of emission reductions in the period up to 2030. This is what grounds for cassation 5.5, 6.1, 6.2 and 6.3 are about.

(v) Lastly, there is the fact that Dutch policy until 2011 was aimed at a 30% reduction by 2020. This is what grounds for cassation 5.5 and 5.6 are about.

Secondly, we will discuss the complaints which, in our opinion, are not so much about the need for the emission reduction as such, but rather, at least in part, about the individual responsibility of the Netherlands. This concerns the following points (paras. 4.178 et seq.).

(i) Does the reduction target from AR4 of 25%-40% in 2020 for the Annex I countries as a group also apply to the Netherlands as an individual country? This is what grounds for cassation 4.3 and 7.1 through 7.5 are about.

(ii) The individual responsibility of the Netherlands for reducing Dutch emissions, given that the Netherlands alone cannot solve the global climate problem. This in particular is what ground for cassation 7.7 is about.

We will then discuss the complaints relating to the effects of the additional Dutch emission reductions if the reduction order is implemented (section 4.199). This is where, to a certain extent, the themes of ‘necessity’ and ‘individual responsibility’ meet.

This concerns, first of all, the need for these additional reductions if they only have a negligible impact on global warming (grounds for cassation 4.4 and 7.6). Secondly, the State argues that it is not necessary for the Netherlands to reduce emissions by at least 25% by 2020, because the EU as a whole will already be doing so (ground for cassation 5.6). Thirdly, the question is whether the positive effect of the reduction order on Dutch emissions could be offset by opposite effects abroad (grounds for cassation 8.5.1 and 8.5.2).

Fourthly, we discuss the complaints about the application of the ECHR by the Court of Appeal, which build on in part from grounds for cassation 1 and 2 (paras. 4.213 et seq.). In it, the State argues that the ECHR does not provide a basis for the reduction order because, supposedly, it would not be effective (ground for cassation 8.2.1), while the Court of Appeal attributed too little significance to other measures, such as adaptation measures (grounds for cassation 8.2.2-8.2.4). Furthermore, according to the State, the Court of Appeal took too little account of the margin of appreciation (ground for cassation 8.3) and failed to subject the reduction order to a fair balance review and proportionality review (ground for cassation 8.4).

Lastly, the remaining complaints of grounds for cassation 4 through 8 are discussed (paras. 4.236 et seq.). They cover various topics: the 450 ppm scenario (ground for cassation 5.2 (para. 1); the precautionary principle (ground for cassation 8.6); relativity (grounds for cassation 8.7.1-8.7.2); the remaining time until the end of 2020 (ground for cassation 8.8); the 1.5°C target (ground for cassation 8.10); and also the complaints in the various grounds for cassation that merely build on from others.

The legal nature of the reduction targets for 2020

This is the first of the five subthemes about the need for a reduction of at least 25% by 2020. These subthemes concern one or more of the following considerations of the Court of Appeal:

'12. (…) AR4 (IPCC Fourth Assessment Report, 2007):

This report describes that global warming of more than 2ºC results in a dangerous and irreversible climate change. To have a chance of more than 50% (‘more likely than not’) that the 2ºC threshold is not exceeded, the report states that the concentration of greenhouse gases in the atmosphere must stabilise at a level of about 450 ppm in 2100 (hereinafter: the ‘450 scenario’). Following an analysis of several reduction scenarios, the IPCC arrives at the conclusion in this report (see Box 13.7) that in order to achieve the 450 scenario, the total emission of greenhouse gases by Annex I countries, including the Netherlands, in 2020 must be 25-40% lower than in 1990. This report also describes that mitigation is generally better than adaptation. (…)

47. In the first place, the Court takes as a point of departure that the emission of all greenhouse gases combined in the Netherlands had dropped by 13%, relative to 1990, in 2017. Even if the new calculation method was not used for this (see para. 21 of this ruling), a significant effort will have to be made between now and 2030 to reach the 49% target in 2030; much more efforts than the limited efforts the Netherlands has undertaken so far. It is also an established fact that it is desirable to start the reduction efforts at as early a stage as possible in order to limit the total emissions in this period. Delaying the reduction will lead to greater risks for the climate. A delay would, after all, allow greenhouse gas emissions to continue in the meantime; greenhouse gases which linger in the atmosphere for a very long time and further contribute to global warming. In that context, the Court would like to point out to the warnings issued by the UNEP, cited in paras. 2.29 through to 2.31 of the judgment. See also the report of the PBL of 9 October 2017 (Exhibit 77 of the State) p. 60, where the PBL remarks that achieving the climate targets of the Paris Agreement not necessarily concerns achieving a low emission level in 2050, but rather and particularly achieving low cumulative emissions, considering the fact that each megaton of CO2 which is emitted into the atmosphere in the short term contributes to global warming. An even distribution of reduction efforts over the period up to 2030 would mean that the State should achieve a substantially higher reduction in 2020 than 20%. An even distribution is also the starting point of the State for its reduction target of 49% by 2030, which has been derived in a linear fashion from the 95% target for 2050. If extrapolated to the present, this would result in a 28% reduction by 2020, as confirmed by the State in answering the Court’s questions.'

48. In AR4, the IPCC concluded that a concentration level not exceeding 450 ppm in 2100 is admissible to keep the 2ºC target within reach. The IPCC then concluded, following an analysis of the various reduction scenarios (in Box 13.7), that in order to reach this concentration level, the total greenhouse gas emissions in 2020 of Annex I countries, of which the Netherlands is one, must be 25-40% lower than 1990 levels. In AR5, the IPCC also assumes that a concentration level of 450 ppm may not be exceeded in order to achieve the 2ºC target. (…)

49. (…) In order to assess whether the State has met its duty of care, the Court shall take as a starting point that an emission reduction of 25-40% in 2020 is required to achieve the 2ºC target.

50. Incidentally, the 450-scenario only offers a more than 50% (‘more likely than not’) chance to achieve the 2ºC target. A real risk remains, also with this scenario, that this target cannot be achieved. It should also be noted here that climate science has meanwhile acknowledged that a safe temperature rise is 1.5ºC rather than 2ºC. This consensus has also been expressed in the Paris Agreement, in which it was agreed that global warming should be limited to well below 2ºC, with an aim for 1.5ºC. The ppm level corresponding with the latter target is 430, which is lower than the level of 450 ppm of the 2ºC target. The 450-scenario and the identified need to reduce CO2 emissions by 25-40% by 2020 are therefore not overly pessimistic starting points when establishing the State’s duty of care.

51. The State has known about the reduction target of 25-40% for a long time. The IPCC report which states that such a reduction by end-2020 is needed to achieve the 2ºC target (AR4) dates back to 2007. Since that time, virtually all COPs (in Bali, Cancun, Durban, Doha and Warsaw) have referred to this 25-40% standard and Annex I countries have been urged to align their reduction targets accordingly. This may not have established a legal standard with a direct effect, but the Court believes that it confirms the fact that at least a 25-40% reduction of CO2 emissions as of 2020 is required to prevent dangerous climate change.

52. Finally, it is relevant noting that up to 2011 the Netherlands had adopted as its own target a reduction of 30% in 2020 (see para. 19 of this ruling). That was, as evidenced by the letter from the Minister of Housing, Spatial Planning and the Environment dated 12 October 2009, because the 25-40% reduction was necessary ‘to stay on a credible track to keep the 2ºC target within reach’. No other conclusion can be drawn from this than that the State itself was convinced that a scenario in which less than that would be reduced by 2020 was not feasible. The Dutch reduction target for 2020 was subsequently adjusted downwards. But a substantiation based on climate science was never given, while it is an established fact that postponing (higher) interim reductions will cause continued emissions of CO2, which in turn contributes to further global warming. More specifically, the State failed to give reasons why a reduction of only 20% by 2020 (at the EU level) should currently be regarded as credible, for instance by presenting a scenario which proves how – in concert with the efforts of other countries – the currently proposed postponed reduction could still lead to achieving the 2ºC target. The EU itself also deemed a reduction of 30% for 2030 necessary to prevent dangerous climate change (see para. 17 of this ruling).

53. The Court is of the opinion that a reduction obligation of at least 25% by end-2020, as ordered by the district court, is in line with the State’s duty of care. (…).'

The complaints in grounds for cassation 4.8, 5.4 and 5.6 are directed first and foremost against the considerations cited above, in particular paras. 12, 48, 51 and 52. They relate to the legal nature of the reduction targets for 2020.

Ground for cassation 4.8 (paras. 1 and 2) concern the findings that a concentration level of up to 450 ppm is ‘permissible’ and ‘may not’ be exceeded, and that in 2020 emissions ‘should’ be 25% to 40% lower. According to the State, the Court of Appeal thereby fails to recognise, put succinctly, that this concentration level (from AR4 and AR5) and this reduction target (from AR4) cannot be qualified as a standard and that they have no reflex effect in determining the State's obligations. Ground for cassation 5.4 (paras. 1 and 3 through 7) repeats these complaints and also projects them on the reference to the COP decisions.

Grounds for cassation 5.4 (para. 7) and 5.6 (para. 6) further argue that, among other things, the Court of Appeal wrongly failed to take account of the fact that the Netherlands will achieve the reduction targets that are binding at the international and European level.

Ground for cassation 5.6 (para. 6) also contains a related complaint, namely that the Court of Appeal’s reasoning implies an opinion on the lawfulness of EU measures and that the Court of Appeal should have requested the ECJ for a preliminary ruling on the matter.

Briefly put, these complaints raise the question of (i) whether the Court of Appeal assumed that the reduction target of 25%-40% by 2020 is based on a legally binding agreement or standard; if this is not the case, (ii) whether the Court of Appeal could attribute significance to this reduction target in specifying the State's duty of care (reflex effect); (iii) whether the reduction targets set at EU level prevent the assignment of reflex effect; and (iv) whether the Court of Appeal should have requested the ECJ for a preliminary ruling on the matter.

As will be explained below, in our opinion these complaints do not hold.

Binding agreement or standard? On the first point, the State in and of itself rightly argues that the reduction target of 25%-40% in 2020 from AR4 is not based on a specific international agreement that is legally binding on the State.

The Court of Appeal did not assume this to be the case either. After all, the Court of Appeal has taken account of the international and European agreements entered into by the State and whether or not those agreements are legally binding on the State (paras. 3.7 and 5 et seq.). The Court of Appeal mentions the legally binding agreements made at EU level, the ETS Directive and the Effort Sharing Decision and the related reduction targets (paras. 16-18).

The grounds for cassation also raise the question of whether the Court of Appeal assumed the existence of a standard that is legally binding on the State (different from an agreement) in respect of the concentration level of 450 ppm in AR4 and AR5, the reduction target of 25%-40% in 2020 from AR4 and the decisions of the COPs. The State wonders whether the Court of Appeal has interpreted all this as ‘necessary in a normative sense’,379.i.e. as international obligations.380.The State has already indicated that it has doubts as to whether the Court of Appeal assumed this to be the case, but it has formulated a number of complaints against this to be sure.381.

As the State rightly points out (in ground for cassation 4.8), the IPCC does not establish binding382.standards, the IPCC does not determine when dangerous climate change occurs, and the IPCC does not determine the emission reduction policy to be pursued in order to achieve the 2ºC target.

The IPCC does, however, report on the relevant scientific insights with regard to, among other things, the consequences of a certain temperature increase, the concentrations of greenhouse gases that give rise to that increase and the reduction pathways that lead to the reduction of global warming to a certain temperature.

The District Court and Court of Appeal – rightly – took the latter as their starting point. For example, the District Court and Court of Appeal consider that the IPCC studies, assesses and reports on the most recent scientific, technical and socio-economic information produced worldwide. Such reports cover existing scientific knowledge on the climate system and climate change; the impact of climate change on the environment, the economy and society and the possible strategies to respond to these changes.383.

Now, the State derives from the formulation of certain legal findings the possibility that the Court of Appeal nevertheless assumed the existence of a specific binding standard. For example, the State points out (in ground for cassation 4.8) that the Court of Appeal refers in findings 12 and 48 to a concentration level that is ‘permissible’ and ‘may not’ be exceeded, and further refers to an emission that ‘should’ be 25%-40% lower in 2020. But this interpretation is incorrect.

It should be borne in mind that the descriptive formulation of the IPCC reports can be represented in a somewhat different way in the court’s style of writing:

For example, the IPCC writes in AR4: 'Confidence has increased that a 1 to 2 oC increase in global mean temperature above 1990 levels (about 1.5 to 2.5 oC above pre-industrial) poses significant risks to many unique and threatened systems including many biodiversity hotspots.'. The District Court presented this by formulating that the IPCC 'established that a global temperature rise of 2°C above the pre-industrial level (up to the year 1850) creates the risk of dangerous, irreversible change of climate'.384.

The IPCC also writes in AR4: 'Similarly, limiting temperature increases to 2°C above pre-industrial levels can only be reached at the lowest end of the concentration interval found in the scenarios of category I (i.e. about 450 ppmv CO2-eq using ‘best estimate’ assumptions).' The District Court ‘translates’ this in such a way that, according to the report, 'a temperature rise of 2°C maximum can only be achieved when the concentration of greenhouse gases in the atmosphere is stabilised at about 450 ppm'.385.

The Court of Appeal also took these findings of fact as its starting point. In its judgment, these findings are formulated even more concisely: 'There has been a general consensus in the climate science community and the world community for some time that the global temperature should not exceed 2ºC. If the concentration of greenhouse gases has not exceeded 450 ppm in the year 2100, there is a reasonable chance that this 2ºC target will be achieved.'386.

Put succinctly, the circumstance that the Court of Appeal refers in findings 12 and 48 to a concentration level that is ‘permissible’ and 'may not’ be exceeded is therefore only intended as a short presentation of the IPCC reports that is comprehensible to the reader of the judgment (with or without scientific training). It cannot be inferred from this that the Court of Appeal has interpreted the concentration level of 450 ppm from AR4 and AR5 (or the corresponding 2ºC target) as a specific standard formulated by the IPCC that is legally binding on States.

The same applies to the question of whether the Court of Appeal has interpreted the reduction target of 25%-40% in 2020 from AR4 as a legally binding standard. This can also be answered in the negative. The District Court387.reproduced Box 13.7 from AR4 and describes its content as follows:

'Following an analysis of the various scenarios about the question which emission reductions are needed to achieve certain particular climate goals, the IPCC concluded that in order to reach a maximum of 450 ppm, the total emission of greenhouse gases by the Annex I countries (including the Netherlands, as explained below) must be lower than in 1990. In this scenario, the total emission of these countries will have to have been reduced by 80 to 95% in 2050 as compared to 1990.'

The Court of Appeal refers to this with the formulations it used in findings 12 and 48. This was not intended to represent anything other than that stated in Box 13.7 of AR4 of the IPCC.

Nor can it be said that the Court of Appeal has construed the decisions of the COPs as a legally binding standard. The Court of Appeal describes the COP as the supreme decision-making body of the UNFCCC, adding that 'the COP decisions are not always legally binding'.388.This is in line with what has already been said about the role of the COP and of COP decisions (see section 4.9 above).

The Court of Appeal considers that the COP decisions are 'not standard with direct effect'. The State now presumes that the Court of Appeal may mean by this that these are in fact ‘standards’ (albeit without direct effect).389.In our opinion, that is not what the Court of Appeal intended to say. After all, in the content of the COP decisions the Court of Appeal sees 'confirmation of the fact' that certain reductions are necessary.390.The Court of Appeal considers the statements of the COPs to be facts confirming the need for certain reductions. It can also be noted that, as will be explained below (in section 4.133), the reference to 'this 25%-40% standard' in para. 51 only expresses this concerns a legally non-binding statement about a ‘fair’ distribution of the reduction effort.

4.100 Finally, it follows from the above that the complaint in ground for cassation 4.8 (para. 3) that the Court of Appeal started from an incomprehensible interpretation of the State’s ground for appeal 2 cannot succeed. Contrary to what this complaint presupposes, the District Court and Court of Appeal did not assume that the IPCC 'establishes norms, emission ceilings and emission reduction targets'.

4.101 It can be concluded that, in connection with the reduction target for 2020, the Court of Appeal did not assume the existence of an agreement or norm that legally binds the State. The complaints of the ground for cassation that do presume the Court of Appeal assuming such therefore cannot succeed.

4.102 Reflex effect? The question then arises as to whether the Court of Appeal could have attributed significance to the reduction target of 25%-40% by 2020 in specifying the State’s duty of care.

4.103 The State argues that its obligations under the ECHR must be given substance on the basis of its legally binding reduction agreements and concludes that these obligations may not be given substance on the basis of the reduction target of 25%-40% (grounds for cassation 4.8 (section 2) and 5.4 (section 5.4)).

4.104 This argument does not hold water. For the manner in which substance should be given to the State’s positive obligations under Articles 2 and 8 ECHR, we refer to the discussion of the common ground method in paras. 2.79 et seq. Contrary to what the State’s argument entails,391.it does not follow from that discussion that the Court of Appeal, in assessing the State’s positive obligations under the ECHR, should focus exclusively on legally binding instruments, such as the reduction agreements that been agreed upon by the Member States at EU level. The court may also look at other sources, such as COP decisions and the underlying reference to the reduction target of 25%-40% in the 2007 IPCC Report (AR4). The same applies to the reduction pathways associated with the 25%-40% reduction target. In its judgment, the Court of Appeal has further explained why, in view of the need for emission reductions in order to achieve the 2ºC target, it attaches more importance to the reduction target of 25%-40% by 2020 than to the EU reduction target of 20% by 2020 (see paras. 4.72-4.76).

4.105 Exclusive effect of EU reduction targets? Even if the ECHR allows for the 25-40% reduction target in 2020 to be taken into account, EU law might in theory force a different conclusion. This could be the case if EU law were to attribute exclusive effect to the reduction target of the ETS Directive and the Effort Sharing Decision. Exclusive effect in this context means that legally binding reduction agreements entered into by the State in an EU context explicitly or implicitly entail that the State cannot be obliged to comply with a certain, possibly more far-reaching reduction target on other legal grounds – such as the ECHR or Article 6:162 DCC.

4.106 In these proceedings, there is no evidence of the exclusive effect of the legally binding reduction agreements entered into by the State.

4.107 The international climate law background of the EU measures do not give rise to the notion that the EU measures have exclusive effect.

The EU Member States pursue a reduction policy collectively, as the EU, aimed at fulfilling their obligations under the United Nations Climate Change Convention, the Kyoto Protocol and the Paris Agreement (sections 4.12, 4.16 and 4.24). Whether the EU achieves its reduction targets is therefore relevant to the question of whether the Netherlands, as a party to these treaties, complies with its international obligations under the treaties. If this were not the case, the individual liability of the Netherlands under these conventions would come back into the picture.392.However, a distinction must be made between compliance with the individual obligations of the Netherlands under the ECHR and compliance with these conventions. The content of the ECHR obligations of the Netherlands must be assessed independently. For the Kyoto Protocol, see section 2.77. The Paris Agreement refers to human rights,393.but only establishes legal relationships between the contracting parties and, unlike the ECHR, does not pertain to the legal relationships between the State and those in its jurisdiction.394.

4.108 In these proceedings, the State asserted that the European ETS system precludes the measures to be taken by the Netherlands to further reduce the emission of greenhouse gases.395.However, this defence was rejected by the Court of Appeal in para. 54. The Court of Appeal held that Article 193 TFEU provides that protective measures adopted pursuant to Article 192 TFEU do not prevent a Member State from maintaining and introducing more stringent protective measures, provided that such measures are compatible with the Treaties. The State’s ground for cassation does not specifically complain about the rejection of this defence.396.

Superfluously: recital 17 of the Effort Sharing Agreement already shows that this Decision is without prejudice to stricter national targets for the non-ETS sectors. There has been no discussion about this in the proceedings. In short, a defence of exclusivity does not play a role in cassation.

4.109 Request for preliminary ruling? The last question to be discussed in this context is whether the Court of Appeal should have referred a question on EU law to the Court of Justice of the European Union (ECJ) for a preliminary ruling.

4.110 This point is raised in the final complaint of ground for cassation 5.6 (para. 6). This complaint is directed against the Court of Appeal’s finding in para. 52 that the State does not observe its duty of care by complying with the 20% reduction by 2020 agreed at EU level. According to the State, this finding implies the opinion that the EU is acting unlawfully as well and/or that the ETS Directive and the Effort Sharing decision are unlawful. According to the complaint in ground for cassation 5.6, the Court of Appeal should not have rendered an opinion on this matter without requesting the Court of Justice of the European Union for a preliminary ruling on, for instance, the validity or legality of the EU measures in question.397.

4.111 Similar questions have been raised in some commentaries on the District Court and Court of Appeal judgments and have been answered both in the negative398.and, cautiously, in the affirmative.399.

It should be borne in mind here that under EU law two types of questions must be distinguished. The first type of questions concerns interfaces between the reduction order and EU law in general. The second type of questions specifically concerns whether the reduction order challenges the legality of EU measures.

4.112 With regard to the first type of questions, the literature identified several interfaces between the reduction order and EU law.

It has been argued, for instance, that the ECJ should assess the significance of COP decisions, because the EU itself is also a party to the United Nations Climate Change Convention and the Kyoto Protocol. It has also been argued that the reduction order should be assessed against the principle of sincere cooperation (Article 4(3) TEU), because this order could influence the international climate negotiating strategy of the EU.400.It has even been suggested that the District Court’s judgment in this case is 'inconsistent with EU law', because the requirements for state liability under EU law (so-called Francovich liability) have not been complied with and because Directive 2004/354/EC on environmental liability does not apply to cases in which the causes of the damage are diffuse, such as the present case.401.This type of questions also includes the possible exclusive effect of the ETS system, which has been presented to and assessed by the Court of Appeal.

4.113 These questions all relate to the interpretation of EU law. The Court of Appeal could, if necessary, have referred questions to the ECJ for a preliminary ruling. However, it should be noted that the Court of Appeal was not obliged to do so. According to Article 267(3) TFEU, that obligation is borne only by a national court or tribunal against whose decisions there is no judicial remedy under national law. The Court of Appeal is not such a court or tribunal. Therefore, it is rightly not asserted in cassation that the Court of Appeal was obliged to refer the abovementioned questions of interpretation to the ECJ.