Climate trials: Legal challenges of a new era – view from France

Tuesday 13 December 2022

Jacques Bouyssou  
Alerion, Paris

Beau ciel, vrai ciel, regarde-moi qui change!
Paul Valery

In report after report, the Intergovernmental Panel on Climate Change (IPCC) stresses that the climate is changing around the world and faster than expected. The extent of human responsibility is becoming clearer. 

The magnitude of the damage has led to worldwide action. Faced with the global nature of a phenomenon that defies borders, with the appearance in the courts of subjects deprived of legal personality (nature, future generations) or with the difficulty of apprehending causality, the law is called upon to reinvent itself. These difficulties do not stop plaintiffs: the multiplication of climate litigation is a major phenomenon in the legal sphere.1

Before the courts of the signatory states of the Paris Agreement,2 plaintiffs can now rely on the normative framework it provides by setting an objective and emphasising the role of non-state actors. National judges must draw on the arsenal offered by their law to render decisions whose scope goes beyond the territorial space of their state: decisions rendered here are commented on there. 

The French judge, who has one of the most sophisticated intellectual constructs in the world, has the means to provide innovative responses to the challenges it faces. Climate litigation represents a laboratory for judges and lawyers. 

The major climate trials and their influence in the world

2015 appears to have been a pivotal year: while public opinion around the world was becoming aware of the seriousness of the consequences of global warming, and states were adopting the Paris Agreement, a court in The Hague handed down a decision that was widely commented on beyond Dutch borders. In the Urgenda case, the judge recognised the existence of a duty of care obliging the Dutch state to act more effectively against climate change. On appeal, the court3 added to this obligation Articles 2 and 8 of the European Convention on Human Rights. 

Elsewhere in the world, in South Africa,4 Australia5 and Colombia,6 states have been attacked for inaction or projects have been subject to requests for cancellation for not taking sufficient account of the climate.

One of the most remarkable features of climate litigation is the mobilisation of the youth and the focus on future generations, who in legal terms cannot be a subject of law. The Juliana case is a very symbolic illustration of this: a young American woman brought an action in the District Court of Oregon to denounce the failure of the United States government to reduce CO2 emissions. The case was based on rights enshrined in the US Constitution (the right to life, liberty and property) and appealed to the public trust doctrine (certain resources cannot be privately appropriated and should be protected by the state). A similar reasoning allowed young Colombians denouncing the deforestation of the Amazon to have their right to a healthy environment, health and water recognised.7 

Everywhere, human rights are invoked in climate matters. The Inter-American Court of Human Rights has recognised the fundamental right to a healthy environment and the impacts of climate change on human rights.8

French responses

The legal tools

At the international level, the European Convention on Human Rights offers means. Used successfully in the Urgenda case, Articles 2 and 8 can also be invoked before the French courts. 

As a result of international cooperation, the Paris Agreement now sets a target that can be used as a measure to determine the effectiveness of climate action. It provides a basis for legal action, especially since the European Union court9  recognises the binding nature of national contributions under the Paris Agreement.

At the domestic level, the French Constitution has included the Charter of the Environment since 2005. 

The legislator regularly adds to the legal arsenal, namely: 
•    the creation of a chapter devoted to compensation for ecological damage in the civil code (Law of 8 August 2016);
•    the inclusion of the ecological emergency and the goal of carbon neutrality in 2050 in the energy code (Law of 9 November 2019);10
•    the creation of specialised environmental courts and a judicial convention of public interest in environmental matters (law of 24 December 2020); and 
•    the translation of part of the 146 proposals of the Citizens’ Convention for the Climate (Law ‘Climate and Resilience’ of 22 August 2021).

Emblematic cases 

The French state and transnational companies have been called to account for their policies and activities.

In 2021, the administrative justice system handed down three decisions that outline the contours of the state's responsibility in climate matters by subjecting French climate policy to judicial review and by recognising the legitimacy of acting on climate matters.

The matter was referred to it by the municipality of Grande-Synthe, located on the coast and directly exposed to the consequences of global warming. In a decision dated 1 July 2021, the Council of State enjoined the government to take additional measures by 31 March 2022, to achieve the objective of reducing greenhouse gas emissions by 40 per cent by 2030.

In the so-called air quality case, the Council of State, considering that the measures taken to improve air quality were not sufficient, has, by a decision of 4 August 2021, condemned the state to pay a penalty of €10 million for the first half of the year 2021 to several organisations and associations involved in the fight against air pollution. It will evaluate the actions of the government for the second semester of 2021 and may fix new penalties.
Finally, the case known as the ‘Affair of the Century’, which is supported by a strong citizen mobilisation (a petition signed by 2 million people), is based on the existence of a general principle of obligation for France to act on climate issues. The Paris Administrative Court was seized for wrongful failure to act on the basis of the IPCC report, the Paris Agreement, the Grenelle Acts 1 and 2, Article 1 of the Constitution and Articles 2 and 8 of the European Convention on Human Rights. In its decision of 3 February 2021, it recognised the fault of the state.

Companies are being targeted both for the damage they cause and for failing to meet their reporting obligations. 

For example, Total is being sued to assess the compatibility of its due diligence plan with the Paris Agreement and for failing to adequately assess the threats to human rights and the environment posed by an oil project in Uganda and Tanzania. The inadequacy of impact assessments with respect to foreseeable environmental effects is used to attack projects that may have adverse climate consequences.

The Council of State defined the judge's new control in climate matters as a ‘trajectory control’. New legal concepts, the duty of care or trajectory control are notions that the state as well as companies must now take into consideration to assess the climate impact of their activities.

Judging differently: the challenges to be met

Global warming and the resulting damage, often very far from the place of emission, escape any notion of borders. The judge is confronted with a global phenomenon which invites them to leave the national sphere and to appropriate the international norm. 

The case of Lliuya vs RWE is representative of this specificity of climate litigation. RWE is one of the biggest emitters of greenhouse gases and a Peruvian, Mr. Lliuya, asked for compensation before a German jurisdiction for the melting of the glaciers in the Andes and the resulting threats for the city of Huaraz. 
In France, the Constitutional Council, relying on the preamble of the Charter of the Environment, consecrated the constitutional value of environmental protection in a decision on 31 January 2020. This decision deals with a situation outside the national territory: the Constitutional Council was seized of the impact on human health and the environment of products prohibited in the European Union in countries authorising their use. 

Climate litigation questions the traditional concept of liability in many respects: admissibility comes up against the difficulty of determining the event giving rise to the damage, and the causal link comes up against the difficulty of attributing damage to a specific perpetrator. 

To overcome the difficulties of establishing causality, the plaintiffs can rely on science and the work on the responsibility of greenhouse gas emissions. The American researcher Richard Heede,11 for example, has drawn up a list of the main perpetrators in the acceleration of global warming. This makes it possible to determine a share of responsibility for each of them. In France, the Climate Action Network identifies the responsibilities of major companies and brings together organisation in the fight for an ecological, sustainable and solidary transition. Such works identify potential responsibilities very far away from the place where the damage is suffered. 

Furthermore, one of the most challenging questions may be how to protect things or natural entities that do not have rights. According to the distinction inherited from Roman law between persons and things, nature – a thing deprived of rights – is at the disposal of man, a subject of law. It can therefore neither initiate an action nor receive reparation. The question of the legal personality of rivers or trees that do not belong to anyone, but nature, should be one of the interesting debates of the century in the legal community.


1.  Subject of study for the ClimaLex research group in France or the Environmental and Natural Resources Law & Policy Program at Stanford 
2.  Paris Climate Agreement of 12 December 2015
3.  Netherlands v. Urgenda Foundation, Court of Appeal of The Hague, 9 October 2018
4.  Earthlife Africa Johannesburg case, North Gauteng High Court, 8 March 2017
5. TAFE, New South Wales, Gloucester Resources Limited v Minister for Planning, 8 February 2019
6.  Corte Constitucional Bogota Comuicado, Expediente D108664 Sentencia C035/16, February 2016
7. Andrea Lozano Barragan y otros v. Presidencia de la Republica y otros, Corte Suprema de Colombia, 7 April 2018
8.  Opinion consultativa Corte Interamnericana de derechos humanos OC-23/17, 15 November 2017
9.  Trib. EU, order May 8, 2019, aff. T-330/18 : OJEU, n° C285, August 13, 2018
10.  Article L. 100-1 A of the Energy Code: ‘a law determines the objectives and sets the priorities for action of the national energy policy to respond to the ecological and climate emergency.’
11.  Richard Heede, ‘Tracing anthropogenic carbon dioxide and methane emissions to fossil fuel and cement producers, 1854–2010’; Climatic Change (2014) 122: 229–241