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Freshfields Sustainability

| 4 minutes read

Deutsche Umwelthilfe (DUH) brings further climate-related constitutional complaints against several German states’ legislation

In December 2021, the German NGO Deutsche Umwelthilfe (DUH) brought further climate-related constitutional complaints against the states of Niedersachsen and Baden-Württemberg on behalf of children and young adults, arguing that the states’ climate acts violate complainants’ constitutional rights.


On 24 March 2021, the German Federal Constitutional Court ruled that the German Federal Climate Protection Act (KSG) is unconstitutional in part due to insufficient emission targets beyond 2030 (see the blog post on the German Federal Constitutional Court ruling). In reaction to that ruling, the German legislator amended the KSG at a federal level in August 2021. In the meantime, DUH targeted 10 federal states for their alleged failure to adopt a climate protection law at state level, or for the inadequacy of adopted climate protection laws. The latest two constitutional complaints concern Niedersachsen and Baden-Württemberg. The amended KSG at the federal level is also again being challenged by children and young people – supported by DUH – before the Federal Constitutional Court with a constitutional complaint submitted on 24 January 2022.

Complaint against Niedersachsen

In December 2020, the state of Niedersachsen enacted a Climate Protection Act (Niedersächsisches Klimagesetz, NKlimaG) to ensure that the state meets international, European and national climate protection targets. The objectives of this law are, among other things, to reduce greenhouse gas emissions by 55 per cent by 2030 compared to 1990 levels and to achieve carbon net zero by 2050.

At the same time, Niedersachsen is now the first federal state in Germany to explicitly mention climate protection in its state constitution (Article 6c). On a federal level and in some other federal states, this constitutional principle is sometimes derived from more general constitutional articles on environment protection, the fundamental right to live etc.

In the case brought by individuals on behalf of DUH against Niedersachsen, the complainants rely on the Paris Agreement and the German federal constitution arguing that the NKlimaG is not sufficient to limit global warming to 1.5°C. In particular, the complainants argue that the NKlimaG does not contain any deadlines or binding measures for the achievement of climate targets and fails to set goals beyond 2030 (as stipulated by the March 2021 Federal Constitutional Court ruling).

Given that the case against the NKlimaG was brought before the Federal Constitutional Court, only the federal constitution will be relevant and not the new Article 6c of the state’s constitution. In Niedersachsen, although a separate constitutional court exists, there is no procedure for an individual’s constitutional complaint before that court.

Complaint against Baden-Württemberg

In 2013, Baden-Württemberg enacted a Climate Protection Act (Klimaschutzgesetz Baden-Württemberg, KSG BW). Like the federal KSG and unlike the NKlimaG, the KSG BW was revised in October 2021 following the Federal Constitutional Court ruling in March 2021.

The KSG BW sets the following climate protection targets: (i) reducing greenhouse gas emissions by 65 per cent by 2030 compared to 1990 levels; and (ii) achieving carbon net zero by 2040 (Section 4 KSG BW). Thus, the KSG BW is even stricter than the amended federal KSG with its carbon net zero target for 2045.

In addition, the KSG BW also provides for concrete measures. These include, in particular, mandatory municipal heat planning for districts and large municipalities, and the requirement to install photovoltaic systems on new buildings.

Despite its ambitious climate protection targets, the complainants argue that the amended KSG BW does not comply with the Paris Agreement. According to the complainants, the KSG BW lacks binding interim targets to 2030 to monitor whether climate protection targets have been met.

Some politicians and experts consider these interim targets a double-edged sword, as they might lead to a focus on short-term measures on a yearly basis (eg by slightly improving existing technologies each year) instead of taking one big step. This could be less flexible, more expensive and less efficient to reach the ultimate reduction goals.

However, given that the Federal Constitutional Court ruled in favour of more detailed reduction plans in its decision on the federal KSG, it might criticise the KSG BW in this regard as well.

Reaction of the states’ governments

Niedersachsen’s government has announced it will amend the NKlimaG by mid-2022 to tighten climate targets in line with the federal KSG, ie to reduce greenhouse gas emissions by 65 per cent by 2030 (instead of 55 per cent) and to achieve carbon net zero by 2045 (instead of 2050).

Moreover, the state’s government plans to include concrete steps to monitor whether the climate protection targets are met, ie by improving the public transport offer.  If the NKlimaG is to be amended as announced, the constitutional complaint will likely be unsuccessful, unless the Federal Constitutional Court takes the view that even such stricter limits and more detailed rules are still insufficient (which would then also be a warning for the federal KSG and other federal states’ climate laws).

The situation for Baden Württemberg is different in two ways: The state’s government does not seem to be willing to amend the KSG BW. However, compared to the targets in the new federal KSG as amended in reaction to the Federal Constitutional Court’s ruling, the reduction targets in the current KSG BW are already as strict as the new federal rules (2030 target) or even stricter (2040 net-zero emissions). It remains to be seen whether the Federal Constitutional Court will find other reasons to criticise the KSG BW apart from the mere reduction targets.


The constitutional complaints lodged against several German states’ climate protection laws are a further example of the new wave of climate-related lawsuits against states, which aim to force governments to adopt stricter climate protection laws. At the same time, lawsuits against companies, also brought by DUH and other NGOs, are emerging in Germany as a result of both the Federal Constitutional Court’s decision and the Shell ruling in the Netherlands (see the blog post on Shell ruling and the blog post on DUH lawsuits against car manufacturers).


climate change, litigation