Guest commentary: A ground-breaking judgment in Germany

By Jaap Spier[1]

On April 29, 2021 the German Constitutional Court (the Bundesverfassungsgericht, or GCC) rendered a ground-breaking judgment, requiring the German government to establish specific plans to achieve its mid-century greenhouse gas emissions goal. (An English press release is available here. The judgment, in German, and an unofficial English translation, along with other documents, are available on the Sabin Center’s Non-US Climate Litigation Database, here.) This blog post first reviews the basic elements of the decision, and then reflects on the its nature and significance.


Germany’s Federal Climate Change Act requires a 55% gradual reduction of German GHGs by 2030 and a reduction of 80-95% by 2050, compared to 1990. To achieve the 2030 target the law determines the permissible emissions for various sectors. For the period after 2030 the law requires that the government determines annually decreasing emissions levels. In 2020 the German population amounted to 1.1% of the world’s population; yet Germany emitted 2% of the global aggregate GHGs.

Several German citizens, and citizens of Bangladesh and Nepal, challenged the German approach. First the 55%: according to them this percentage is too low. Secondly, they contended that the reduction burden was unduly carried forward until after 2030, which would jeopardise freedom rights of the present and future generations. Their claim was based on alleged violation of fundamental rights (life and corporal integrity, ¶145)[2] and the adverse consequences of passing the 1.5C threshold.

Key features of the judgment

The GCC found that all plaintiffs/natural persons had “standing” (¶90). The GCC did not answer the question whether the rights of the foreign plaintiffs were violated (¶173/4). The duty to protect plaintiffs from Nepal and Bangladesh would not necessarily have the same content compared to people living in Germany (¶176-178).

In adopting the temperature targets of the Paris Agreement the German legislature exercised its mandate and prerogative. This threshold can “in principle” be converted into a global carbon budget, which, in turn, can be allocated to States. The GCC refers to the various scenarios painted by the Intergovernmental Panel on Climate Change (IPCC) and the degree of uncertainty. It also refers to calculations of the German Advisory Council on the Environment (GAC) to the effect that, based on a 67% probability and a threshold of 1.75C, the carbon budget will be almost entirely depleted by 2030 (¶¶231-233 and ¶246); the GAC adopts a per capita allocation to determine the German carbon budget (¶225). According to the GCC the 1.75C threshold is not overly stringent (übermässig streng), i.e. lies within the boundaries of what is legally required (well below 2C and if possible no more than 1.5C). A reduction trajectory based on 1.75C does not achieve the 1.5C-goal (¶235). The GCC mentions the GAC’s assumptions and the uncertainties, which imply that the GAC’s findings cannot serve as “an exact numerical benchmark” (¶236 and ¶247).

The protection of life and physical integrity encompasses protection against the adverse consequences of climate change, as a rule including future generations in case of irreversible developments (Das gilt erst recht, wenn unumkehrbare Entwicklungen in Rede stehen, 146). These rights are not violated, in view of the legislature’s wide margin of discretion; the same goes for adopting the targets of the Paris Agreement. The GCC notes that adaptation can provide additional protection (under ¶164/5). (As an aside, in the Urgenda judgment, the Dutch Supreme Court rejected the argument that adaptation could be an alternative to reduction of emissions.[3])

The GCC upheld the 55% reduction-requirement until 2030. (The requirement does not include land use, forestry, and emissions caused by international air and sea transport which are attributed to Germany, ¶124.) The German climate goals are based on the target of the Paris Agreement to keep global warming well below 2 and preferably to 1.5C (¶159); adopting these goals is a matter of climate policy (klimapolitische Frage, ¶35). The IPCC Special Report of 2018 is not saying that the 1.5C threshold must not be passed. Adopting the relevant threshold is of a normative nature and requires reconciling the requirements of health protection with conflicting concerns. However, adopting a 1.5C threshold limits the likelihood that tipping points will be passed, a point also made by the Dutch Supreme Court in its Urgenda judgment under ¶4.4 and by the Irish Supreme Court under ¶3.7[4]). Keeping the increase of global temperature well below 2C and, possibly (möglichst) at 1.5C is politically insufficiently ambitious, but such a choice remains within the significant discretion of the legislature (¶¶159-162). The GCC notes that there is some reason to believe (Anhaltspunkte) that the reduction trajectory until 2030 makes it impossible to realise the 1.5C ambition, whereas a 1.75C goal is only within reach if extraordinarily burdensome reductions measures are effectuated after 2030. It seems, however, possible to realise the 2C goal. As long as the legislature links its reduction trajectory to the Paris Agreement, the reduction-trajectory until 2030 does not violate the Constitution (¶¶166-168 and ¶242) if after 2030 sufficient and not overly burdensome measures will be taken (¶244).

The reduction measures after 2030 required by the German Constitution will be so significant that they entail a major risk of a serious and adverse impact on constitutional rights (¶245). It takes time to achieve far-reaching implementation of the innovations required in almost all sectors of the economy (umfassende Implementierung solcher Innovationen in nahezu sämtlichen Wirtschaftsabläufen, ¶121). Fundamental rights could be jeopardised if society-wide reductions (the GCC mentions production, services, infrastructure, government, culture and consumption) after 2030 would have to be achieved within a very short time-frame (¶246). It could potentially be detrimental to almost every type of freedom (¶117). The required reductions until 2030 determine what needs to be done after 2030, in that all remaining emissions have to be curbed (¶118). The GCC determined that the legislature has to formulate transparent guidelines for the further structuring of GHG reductions at an early stage and provide an orientation for the required development and required implementation processes and conveying a sufficient level of developmental urgency and planning certainty. Clarity about the required transition trajectory concerning products, services and other items will create pressure to change course (¶249 and ¶252/3). The legislature must specify no later than 31 December 2022 “the reduction goals for time spans after 2030” (¶268 i.f.). The GCC emphasises that technological developments and new scientific insights have to be taken into account. That means that the relevant “rules” are not and should not be cast in stone (¶262).

The GCC reminds us of its earlier case law pointing to an ecological minimum standard and, by the same token, a protection against catastrophic or apocalyptic events (the German word, which is difficult to translate, is Ausmasz, ¶114). The GCC noted that action is necessary to ensure catastrophes will not occur, and that if Germany complies with its obligations until 2030 it can contribute to, though not provide, the solution of the global problem (¶115).

A few thoughts

Though it was unanimous (¶270), I cannot escape the impression that the judgment is a hard-fought compromise. It seems to hinge on not easily reconcilable thoughts, i.e. the margin of discretion of the legislature and the need to protect fundamental rights.

Emissions until and after 2030

The GCC rightly emphasises that to the extent present day emissions are allowed, the impact on future freedom will be significant because it narrows the remaining reduction options. The GCC sympathetically ruled that one generation should not be allowed to consume large portions of the carbon budget while bearing a relatively minor share of the reduction effort, if this would leave subsequent generations with a drastic reduction burden and expose their lives to comprehensive losses of freedom. It is quite a challenge to strike a balance between the diverging interests of the present and future generations.

The GCC, seemingly grumbling, upheld the reduction-trajectory until 2030. Make no mistake: 55% is almost certainly insufficiently ambitious for affluent countries such as Germany with a relative high level of per capita emissions. It is crystal clear that the Court is aware of this inconvenient truth, seeing its reference to the IPCC and GAC findings.

In a sense it is understandable that the GCC shied away from saying that 55% fell short of the reductions Germany had to achieve until 2030. Other courts also struggle with this kind of case. By way of example: in the Urgenda judgment the Dutch Supreme Court develops the feature of minimum obligations required by art. 2 and 8 ECHR; the Irish Supreme Court meticulously confined itself to assessing the requirements of Irish climate law.

Courts increasingly feel the brunt of society’s unwillingness to come to grips with the challenges posed by climate change. Plaintiffs are ever more creative and demanding. Like many others I hope that courts will save our planet/humankind. It is, however, up to debate whether many of them will feel in a position to issue the far-reaching relief required to achieve that desideratum. As time progresses and ever more countries experience often unprecedented natural catastrophes, many judges may be prepared to render truly courageous judgments. It is equally possible and, I’m afraid, not unlikely, that many courts will not be prepared to assume full responsibility for the mess created by society. See Brian Preston’s brilliant analysis, The End of Enlightened Environmental Law, Journal of Environmental Law 2019, 31, 399-411.

Understandably, the Court leaves the legislature a wide margin of discretion. Even with the just mentioned caveats, to me the judgment is unconvincing:

  • According to the GAC there is a 67% probability that the German carbon budget will be almost depleted by 2030 if a 1.75C threshold is adopted. The remaining reductions will need to be reduced at a significant pace after 2030, which obviously creates a major risk, if not a certainty, that the interests of those living after 2030 will be hugely compromised. Admittedly, it will help a little bit if those concerned know in advance that they have to reduce their remaining GHG emissions to zero within a few years (in this scenario 2050 is a phantom), it will require Herculean efforts and will significantly jeopardise many fundamental rights.
  • The GCC labels the 1.75C threshold as not overly stringent. That makes it even more difficult to understand why the legislature is allowed to rely on “well below 2C” which includes a (potentially) higher threshold of, say, 1.9C.
  • It may be true that, in the short term, adaptation can solve part of the adverse consequences of runaway climate change in Germany. It is, however, no more than speculation. Precisely in light of the uncertainties mentioned by the GCC, we cannot know the future. We are also in the clouds concerning tipping points. So much is clear: there is a credible risk that tipping points will be passed well before passing the 2C-threshold, as the GCC acknowledges. Hence, we cannot assess whether adaptation will be an adequate surrogate for emission reductions. Even if that would be the case in Germany and other countries similarly exposed to the unevenly divided adverse consequences of climate change, it certainly brings no solace to all countries and people. In many countries, such as the Small Island States, Bangladesh, and the Philippines, adaptation is not the answer. If possible at all, these countries do not have the funds to take the necessary measures. Last but not least: the precautionary principle requires that potentially colossal damage be averted.
  • Germany seemingly still aims (hopes?) to avoid passing the 1.5C threshold. Assuming that this is more than lip-service paid to the Paris Agreement and the IPCC’s 2018 Special Report, Global Warming of 1.5 ºC, ignoring the GAC findings without a credible explanation is not easy to justify.


There is a significant probability that the measures that in most credible scenarios have to be effectuated after 2030 will come at a very heavy price in terms of freedoms and other rights the German Constitution aims to protect. If the GCC really cared about the likely draconian impact on a series of constitutional rights after 2030, as I am sure it did, it should have been more courageous. It should have been less lenient concerning the permissible emissions until 2030. I realise that this is easier said than done, of course. I know from19 years of experience in the Dutch Supreme Court that the administration of justice poses challenges and that there are limits to what judges can reasonably do.

The importance of a keen understanding of what needs to be done

The GCC hits the mark that it is desirable to know well in advance which measures have to be taken by whom and when. As a rule, many measures cannot be taken overnight. By way of example: switching to wind farms requires drafting a concrete plan, (probably) seeking permits, buying the equipment, putting it in place, and perhaps borrowing money; the grid may need to be adapted.

The GCC’s slightly ambiguous reference to “planning certainty” entails a risk. It is against the odds that we will be spared of nasty future surprises, including depletion of the global carbon budget at a much higher pace than currently expected, new and worrying insights from climate science, passing one or more tipping points, or a much higher than expected level of non-anthropogenic GHGs. Governments, enterprises and society at large must be brought to understand that the lethargy of the past may, and likely will, imply that present day’s estimates may be way too optimistic. This, in turn, may mean that investments in transition will turn out to be hugely insufficient, and by the same token potentially a waste of money because more or other measures had to be taken. Seeing the many uncertainties, there is not such a thing as “planning certainty”. This being said, the GCC is right that without knowledge of what needs to be done by the respective players, the required measures are unlikely to be taken.

The desirability to determine the legal obligations of key players was the reason why a group of experts drafted the Oslo Principles (OP) and the Principles on Climate Obligations of Enterprises (EP). These Principles aim to map the legal obligations of respectively States (OP) and enterprises, investors and a few other key players (EP); see, also for the members of the respective groups and the commentaries to the Principles The core reduction obligation of States and on its heels of enterprises is reformulated in Principle 2.2.1 of the second edition of the EP (EP2), available at the same website. The global carbon budget, to be re-determined every five years, is the backbone of the allocation of the carbon budget of States. Like the GAC, the EP2 is based on a 1.75C threshold. The commentary explains why there is a fair chance that the global carbon budget will be depleted well before 2050. Like the GCC and the GAC, the EP2 emphasises that the reductions to be achieved by affluent States with relatively high GHG emissions per capita will need be steep (the OP allocates reduction obligations on a per capita basis). Hence, there are striking similarities between the GCC judgment, the GAC-approach and the OP and EP(2).

Intergenerational equity

Frank Biermann’s “first reflections” hail the German judgment as a “huge win for the principle of intergenerational justice.” He may be right. To me, it is not overly clear whether the judgement would have been any different without taking the interests of future generations (the plural begs questions) into account. After all, a major part of present day’s population will still be around between 2030 and 2050, even if it would be right that affluent countries would still have 30 years (until 2050) to do their part of the job, an extremely unlikely scenario.

A swift political reaction

Shortly after the judgment the German Finance Minister and the Environment Minister laid out a legislative proposal to become carbon neutral between 2045 and 2050 and to curb emissions to be 65% of 1990 levels by 2030 and 88% of 1990 levels by 2040. However welcome and ambitious, as such and in relation to the goals formulated by most other countries, even these targets may not suffice. Time will tell whether the GCC will accept them as remaining within the political manoeuvring room of the legislature. If the legislative proposals would become law, and if the GCC would stick to its judgment, the legislature will have to explain how these new targets have to be achieved.



[1] Former Advocate-General of the Supreme Court of the Netherlands, senior associate University of Cambridge Institute for Sustainability Leadership, Extraordinary Professor of Global Challenges University of Stellenbosch (South Africa).

[2] Figures between parentheses refer to the relevant paragraphs of the judgment.

[3] ECLI:NL:HR:2019:2007 for the unofficial English translation under 7.5.2.

[4] Friends of the Irish Environment CLG v. Government of Ireland (Supreme Court of Ireland, July 31, 2020), available at