The Federal Constitutional Court’s Climate Change Order and the interplay between international and domestic climate protection law

Published: 11 May 2021 Author: Stefan Talmon

In December 2015, the States Parties to the United Nations Framework Convention on Climate Change (UNFCC) gathered in Paris for their twenty-first Conference of the Parties (COP21). The conference concluded on 12 December 2015 with the adoption of the Paris Agreement, a   legally binding international treaty on strengthening the global response to the threat of climate change. The Agreement was opened for signature at the United Nations Headquarters in New York from 22 April 2016 to 21 April 2017. Germany was among the first States to sign the Agreement on 22 April 2016 and deposited its instrument of ratification with the UN Secretary-General on 5 October 2016. The Paris Agreement entered into force on 4 November 2016. In the Order of the German Federal Constitutional Court of 24 March 2021 concerning various constitutional complaints against the Federal Climate Change Act, the Paris Agreement played a prominent role. In its 110-page long decision, the Court referred no fewer than 40 times to the Agreement or its provisions. The Federal Constitutional Court’s Order provides a good example of the interplay between international law and German domestic law.

The Federal Constitutional Court was seized with the questions of whether the Federal Climate Change Act violated the legislator’s constitutional duty to protect the complainants from the risks of climate change and whether it failed to satisfy the obligation arising from Article 20a of the Basic Law, the German Constitution, to protect the natural bases of life by legislation. The link between international law and German domestic law was established by the Federal Climate Change Act, which was based on the obligation under the Paris Agreement to limit the increase in the global average temperature to well below 2°C and preferably to 1.5°C above pre-industrial levels so as to minimise the effects of worldwide climate change, as well as the commitment made by the Federal Republic of Germany at the United Nations Climate Action Summit in New York on 23 September 2019 to pursue the long-term goal of greenhouse gas neutrality by 2050. The Paris Agreement itself aimed “to strengthen the global response to the threat of climate change, in the context of sustainable development and efforts to eradicate poverty, including by:

“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, recognizing that this would significantly reduce the risks and impacts of climate change.”

The Federal Constitutional Court approved of the Paris climate protection target, stating:

“Whether and to what extent the CO2 concentration in the Earth’s atmosphere and the rise in temperature should be limited is a question of climate policy. It cannot be answered by the natural sciences. Their findings, however, provide indications of the reductions that are necessary in order to achieve a specific climate protection target. In this respect, climate science and climate policy use different target and measurement parameters that refer to temperature, CO2 concentration in the atmosphere or CO2 emissions The Paris climate targets were formulated as maximum warming or temperature targets. The methodological advantage of such a temperature target is that it is directly related to the consequences of global warming because the mean temperature of the Earth is a key parameter for the state of the Earth system as a whole.

However, in order to turn a global temperature target into targets for the reduction of CO2 emissions, climate-physical conversions of warming into amounts of emitted CO2 are necessary. In view of the correlation between CO2 concentration and global warming, this is possible in principle, even though the conversion is associated with uncertainties due to the complexity of the climate system. […]  [These conversions show] the total amount of CO2 that can still be emitted (globally) if the resulting warming of the Earth is not to exceed the temperature threshold. This amount is referred to as the ‘CO2 budget’ in the climate policy and climate science debate.”

The Paris Agreement and the constitutional duty to protect life, health and property

Once the Federal Constitutional Court had approved the Paris climate target and the resulting CO2 budget, the Court applied these parameters in its examination of whether the legislator, by adopting the Federal Climate Change Act, had met its constitutional law obligation to protect life, health and property of the complainants against the risks posed by climate change, including climate-related extreme weather events such as heat waves, forest fires, hurricanes, heavy rainfall, floods, avalanches, and landslides.

The complainants argued that the legislator had violated the constitutional duty to protect their life, health and property against the risks posed by climate change. In particular, they considered the temperature target in the Paris Agreement limiting the increase in the average global temperature to well below 2°C and, if possible, to 1.5°C above the pre-industrial level (the “Paris target”), which formed the basis of the Federal Climate Change Act, to be inadequate. The complainants asserted that the State’s constitutional duty of protection could only be fulfilled if the aim was pursued to limit global warming to a maximum of 1.5°C.

The Federal Constitutional Court acknowledged that there was a widely held view that an average global warming of more than 1.5°C would have significant climate consequences. But this was not enough to dislodge the Paris target adopted in the Federal Climate Change Act given the leeway afforded to the legislator in fulfilling these duties of protection. The Court stated:

“If the legislator has nevertheless based national climate protection law on the agreement of the Parties to the Paris Agreement to limit global warming to well below 2°C and, if possible, to 1.5°C, this may be judged politically to be too unambitious. However, in view of the considerable uncertainty […] the legislature currently has considerable leeway for decision-making in fulfilling its duty to protect fundamental rights, especially since it must also reconcile the requirements of health protection with conflicting interests.

Contrary to the complainants’ opinion, it cannot currently be established that the legislator has exceeded this leeway by basing its action on the Paris target. […] It cannot be ruled out from the outset that a temperature threshold of 1.5 °C may be advisable to limit climate change, but that the Paris target adopted by the German legislature of limiting the temperature increase to well below 2°C and, if possible, to 1.5°C is sufficient to protect human life and health.”

The Federal Constitutional Court used international treaty law – the Paris target – to determine whether the legislator “currently” met its constitutional duty of protection. The Paris target, however, was not treated as cast into stone. It only provided a yardstick to determine whether the legislator, at that moment in time, had properly exercised its leeway under the Constitution. This leeway was not tied to the Paris Agreement but was subject to the latest developments and findings in climate science.

The Paris Agreement and a constitutional duty of protection with regard to foreigners living abroad

Several of the complainants lived in Nepal and Bangladesh. They argued that the Federal Republic of Germany had violated its constitutional duty to protect their life, health, and property due to insufficient climate protection efforts. The Federal Constitutional Court left open the question of whether such a duty of protection existed with regard to people living abroad because the Federal Climate Change Act did not violate such a duty. The Court stated:

“As has been seen, the legislature cannot be reproached for not having taken measures to limit climate change at all or for having only taken such regulations and measures that would be obviously unsuitable or completely inadequate to achieve the required protection goal. In particular, Germany has acceded to the Paris Agreement on Climate Change and in section 1, sentence 3 of the Climate Change Act, the federal legislator has made both the obligation under the [Paris] Agreement and the commitment of the Federal Republic of Germany to pursue greenhouse gas neutrality by 2050 as a long-term goal the basis of the Climate Change Act.”

The fact that Germany had ratified the Paris Agreement and started to implement the Paris target at the national level was considered sufficient by the Federal Constitutional Court for Germany to have fulfilled any obligation that may exist under the Basic Law vis-à-vis complainants living abroad. The Paris Agreement was thus used to determine whether the legislator had met its duty of protection within the leeway afforded by the Basic Law.

The Paris Agreement and the violation of a constitutional right to an ecological minimum standard of living

The complainants also argued that the Federal Climate Change Act violated their constitutional right to an ecological minimum standard. Physical survival and the opportunities to maintain interpersonal relationships and to participate in social, cultural, and political life could not be guaranteed through economic safeguards alone if all that was left was an environment that was radically changed by climate change and hostile to human life. The State was therefore under an obligation to protect against environmental damage of catastrophic or even apocalyptic proportions. The Federal Constitutional Court left open the question of whether the Basic Law protected such a right because it found that the legislator could not have violated such a right. The Court explained:

“[I]t cannot be established that the State has violated requirements that could be addressed to it in order to avoid conditions of catastrophic or even apocalyptic proportions threatening [human] existence. Germany has acceded to the Paris Agreement and the legislator has not remained idle. In the [Federal] Climate Change Act, it has laid down concrete measures for the reduction of greenhouse gases. These reduction targets, which are laid down until 2030, do not lead to climate neutrality, but will be continued with the long-term goal of achieving greenhouse gas neutrality by 2050. On this basis, it seems possible, with appropriate efforts, that – to the extent that Germany can contribute to solving the problem – catastrophic conditions can be prevented in any case.”

For the Federal Constitutional Court, ratifying the Paris Agreement and implementing the Paris target at the national level was all Germany was required to do to meet any constitutional law obligation to avoid existence-threatening conditions of catastrophic or even apocalyptic proportions.

The Paris Agreement and the constitutional duty to take climate action

Article 20a of the Basic Law obliges the State to protect the natural foundations of life by legislation, also mindful of its responsibility towards future generations. From this provision, the Federal Constitutional Court derived an objective obligation of the State to take climate action. This obligation was not precluded by the fact that climate and global warming were global phenomena and that the problems of climate change could not be solved by the mitigation efforts of any one State on its own. The climate action mandate enshrined in Art. 20a of the Basic Law possessed a “special international dimension”. The provision precisely obliged the State to turn to the international level for a solution of the climate problem because a solution to the global climate problem was only possible if climate protection measures were taken worldwide. In particular, the Federal Government was obliged to work towards solving the problems of climate change within the framework of international coordination, for example through negotiations, in treaties or in organisations. This is not so much an enhanced  “international law-friendly reading of the constitution”, but a reading informed by practical realism. As climate change is a global phenomenon, the constitutional duty of protection can only be fulfilled through international cooperation. No one is protected against the risks of climate change unless everyone is protected. The Federal Constitution Court held that the path to globally effective climate protection indicated by Art. 20a of the Basic Law “currently leads primarily via the Paris Agreement.”

Article 20a of the Basic Law does not provide a justiciable yardstick for the constitutional assessment of concrete greenhouse gas reduction targets set by the legislature. It rather leaves the legislature with considerable leeway to determine these targets. According to the Federal Constitutional Court, the open normative content of the provision and the express reference to legislation did not, however, preclude constitutional review of the climate action taken by the legislator. In exercising its mandate and prerogative to specify the reduction targets under Article 20a, the legislator adopted the climate target of the Paris Agreement, according to which the increase in the global average temperature should be limited to well below 2°C and preferably 1.5°C above pre-industrial levels. The Federal Constitutional Court held that by choosing the Paris target the legislator did not currently exceed its legislative leeway. The Court explained:

“The selected temperature threshold is not only an expression of the current political will but is also to be understood as a specification of the constitutionally required climate protection goal. This is supported above all by the fact that the climate protection target specified in section 1 sentence 3 of the Federal Climate Change Act is the internationally agreed temperature threshold of Article 2(1)(a) of the Paris Agreement, which the legislature has deliberately and expressly chosen as a basis. In its constitutional significance, this goes beyond the German legislature’s consent to the Paris Agreement given by treaty law. The fact that the Paris target is designated as the basis of the Federal Climate Change Act is closely related to the climate protection requirement of Article 20a of the Basic Law. Because of the genuinely global dimension of climate change, the State can ultimately achieve the goal of Article 20a of the Basic Law to halt climate change only by international cooperation. To this end, it acceded to the Paris Agreement, within the framework of which it now also fulfils its more far-reaching climate protection obligations under Article 20a of the Basic Law. By inscribing the temperature threshold of Article 2(1)(a) of the Paris Agreement into domestic law, the legislature has determined the fundamental orientation of national climate protection law precisely in such a way so that the German State has the opportunity to effectively fulfil its constitutional mandate to protect the climate through its own efforts within an international framework.

However, the legislature is not completely free to specify the climate protection requirement of Article 20a of the Basic Law. Nevertheless, with the temperature target chosen in the Paris Agreement, and specifically again in the Federal Climate Change Act, the leeway for specification left by Article 20a of the Basic Law is currently respected. The chosen climate protection target is covered by the legislator’s prerogative of specification laid down in Article 20a of the Basic Law. The Paris Agreement was adopted in December 2015 on the basis of scientific findings compiled in preparation for the Paris Climate Conference. According to the complainants, the warming must be further limited to a maximum of 1.5°C. This corresponds to a widespread assessment and is based in particular on the [Intergovernmental Panel on Climate Change (IPCC)] 2018 special report on the consequences of global warming of 1.5°C. However, because of the considerable uncertainty documented in the ranges and uncertainties given by the IPCC, Article 20a of the Basic Law – like the duties of protection resulting from fundamental rights – also allows the legislature some leeway in assessing the dangers and risks in a politically responsible way when determining the climate protection target. In any case, it is not apparent that at present the limits of this legislative leeway are violated by choosing the Paris target.”

In terms of constitutional law, the Paris target is, however, no more than a snapshot of current climate science and policy. The Federal Constitutional Court made it quite clear that the Paris target was neither a target set by constitutional law nor was it the only constitutionally valid target. It neither lent the Paris target “constitutional force”, nor did it embed it into the Constitution and make it “the standard of review for the Constitutional Court.” The Paris target was just one target among several the legislator could choose within the leeway afforded to it by Article 20a of the Basic Law. The Court also made it clear that in future the Paris target might no longer meet the constitutional requirements, stating:

“However, new and sufficiently reliable findings on the development of anthropogenic global warming or its consequences and its controllability could make it necessary to set a different target within the framework of Article 20a of the Basic Law, even taking into account the legislature’s leeway for decision-making. This is subject to review by the constitutional court. Article 20a of the Basic Law imposes a permanent duty on the legislature to adapt environmental law to the latest developments and findings in science. If the temperature target agreed in Article 2(1)(a) of the Paris Agreement proves to be inadequate to achieve sufficient climate protection, the obligation under Article 20a of the Basic Law to seek a solution to the climate protection problem at the international level is also updated; in particular, efforts would have to be undertaken to achieve stricter agreements. On the other hand, a reorientation towards weaker climate protection goals would have to be justified before Article 20a of the Basic Law because of the associated ecological regression, unless more recent and sufficiently reliable findings in climate research show that global warming has less damaging potential than is currently to be feared.”

In the end, the Federal Constitutional Court held that the Federal Climate Change Act was in part unconstitutional not because it adopted the Paris target but because it did not specify the reduction pathway for greenhouse gas emissions for the period from 2031 to 2050 in order to meet Germany’s commitment to achieve greenhouse gas neutrality by 2050.

The Federal Constitutional Court’s Order well illustrates the interplay between domestic and international climate protection law. The Court first established the “specific international dimension” of Article 20a of the Basic Law which requires Germany to take climate action at the international level, such as by negotiating and joining the Paris Agreement strengthening the global response to the threat of climate change. Once the legislature had adopted the climate protection target of the Paris Agreement in the Federal Climate Change Act, the Paris target – as part of ordinary domestic law – became subject to constitutional review. The Court thus did not turn to international law or international institutions such as the IPCC to define the constitutional law duties to protect life, health, and property against the risks posed by climate change and to take climate action, but examined whether the legislature, when adopting the Paris target, stayed within the decision-making leeway afforded by the Constitution. This is by no means a “truly international […] approach to constitutional law.” On the contrary, this is another example of subjecting international law commitments and international approaches to constitutional scrutiny. In this respect, the Federal Constitutional Court remains true to its dualist approach to the relationship between international and Germany domestic law with constitutional law remaining at the helm.

Category: International law and German law

DOI: 10.17176/20220627-172853-0

Author

  • Stefan Talmon is Professor of Public Law, Public International Law and European Union Law, and Director at the Institute of Public International Law at the University of Bonn. He is also a Supernumerary Fellow of St. Anne’s College, Oxford, and practices as a Barrister from Twenty Essex, London. He is the editor of GPIL.

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