The pursuit of climate justice is gaining significant momentum in the courts. Global Insight assesses whether – given the sudden backlash against climate action – this can continue.

The year 2025 is set to be significant for climate justice. Two advisory opinions will be handed down by international tribunals, the International Court of Justice (ICJ) and the Inter-American Court of Human Rights respectively. Together, these judgments are expected to solidify the legal link between climate action, human rights and the obligation of states to protect their citizens from the harms created by the climate crisis.

Meanwhile, the era of climate litigation that began in earnest after the signing of the Paris Agreement in 2015 is expected to continue. Jonathan White, a lawyer in the London office of environmental law charity ClientEarth, highlights that many climate cases are expected to reach a conclusion in 2025, with a number of judgments handed down.

For example, Germanwatch is spearheading Peruvian farmer Saúl Luciano Lliuya’s case against German utility giant RWE, a transnational lawsuit expected to conclude in 2025 that will set a precedent regarding whether emitters can be held accountable for the impacts of the climate crisis felt in other parts of the world. In March, the Higher Regional Court in Hamm will hear the case, which is nine years in the making. Saúl Luciano Lliuya claims that because of RWE’s greenhouse gas (GHG) emissions, it has some responsibility for the melting of mountain glaciers near his town of Huaraz. RWE argues that a single company can’t be held responsible for the consequences of climate change.

Elsewhere, however, the fight for climate justice is being hampered. As climate litigation cases have increased in number, so too have strategic lawsuits against public participation (SLAPPs) intended to shut them down. And in the US, the new administration of President Trump has already taken significant steps to gut the country’s climate action (see below: The gutting of US climate action). Climate justice stands, then, at a tipping point.

The climate litigation era

A number of recent cases have seen claimants seek to hold governments and corporations to account for their involvement in worsening the climate crisis or their failure to take adequate steps to counter the emergency.

When the Paris Agreement was signed in 2015, the climate litigation era began, as lawyers could rely on legally enshrined climate change commitments to hold governments and corporations to account in the battle to reduce GHG emissions.

According to a report published by the Grantham Research Institute in partnership with the Sabin Center for Climate Change Law in summer 2024, over 2,600 climate litigation cases have been filed globally, with 70 per cent of these brought since the adoption of the Paris Agreement.

‘There has been an exponential rise in climate and ESG-related litigation, including an increase in ESG related litigation against companies not just in relation to their own actions but also related to their [subsidiaries] and supply chains’, says Shona Frame, Membership Officer of the IBA Section on Energy, Environment, Natural Resources and Infrastructure Law (SEERIL).

‘Claims alleging violations of rights to life, health or a clean environment have gained traction’, adds Kleber Luiz Zanchim, Council Member for the IBA SEERIL. ‘Companies could be held accountable for failing to mitigate known risks. Courts are increasingly scrutinising whether companies have met their duty of care in addressing foreseeable environmental and social harm.’

While most corporate lawsuits have been brought against the fossil fuel industry, lawyers are increasingly targeting other sectors such as airlines, food and beverages and financial services. ‘Since 2016, we’ve seen a huge spike in climate litigation, but we’re yet to really see the long-term effects of that litigation’, says Lara Douvartzidis, Senior Legal Executive at the Net Zero Lawyers Alliance. There’s a need, then, for victories in the courtroom to lead to an impact on the ground.

Forcing the hand

In its advisory opinion, the ICJ will provide its interpretation of the role states have to play in shielding their people and the environment from the harmful effects of the climate crisis. Meanwhile, the Inter-American Court of Human Rights will set out its views on the obligations of states in responding to the climate emergency.

Together these opinions are expected to lead to an increase in climate litigation cases around the globe. This is because, although they’re not legally binding as such, the opinions will provide a foundation for connecting basic human rights with climate action. Ultimately, they’ll help force the hands of governments and corporations to take further meaningful steps in reducing GHG emissions.

Commentators don’t predict that the floodgates will open entirely for climate litigation, however, even after the advisory opinions are issued. Climate litigation is highly strategic and requires intense resources in terms of legal staff, experts, time and funds, which means cases are very carefully selected.

‘We’re often seeing the issue that courts are struggling with their role within climate litigation’, says Francesca Mascha Klein, Legal Officer for Strategic Litigation at advocacy organisation Germanwatch. ‘There’s often a hesitancy to decide because there’s this idea that climate protection is a political decision. But increasingly, courts are acknowledging what’s happening beyond their own jurisdictions, so we’re seeing more courts work with international [judgments].’

The growing influence of climate litigation is also underscored by the fact that defendants have begun to attack courts that have handed down rulings in favour of climate advocates. In Switzerland, for example, the lower and upper chamber of the country’s parliament voted to reject the ECtHR’s judgment in the KlimaSeniorinnen case, accusing the Court of judicial activism.

‘States and corporations, unable to win on the facts and the law, are lashing out at the claimants and the courts that hear their claims. That backlash, in many ways, is a testament to the power of climate litigation to get to the heart of the matter and to compel governments and companies to change course’, says Reisch.

Another measure taken by some defendants, especially in the fossil fuel industry, is to file SLAPP cases. These are lawsuits brought against activists and others who speak out about matters of public interest and they often relate to the climate crisis and the environment, according to the Grantham Research Institute on Climate Change and the Environment at the London School of Economics. The growth in SLAPP lawsuits is directly related to the rise in successful climate cases.

‘SLAPP suits or other forms of backlash are unfortunately going to be a larger and larger share of legal activity’, says Reisch. ‘We’ve seen some major moves in the last year, not only by companies slapping back against climate activists and advocates, but even bringing suits against their own shareholders who sought to bring climate risk to the board’s attention, for example. That’s a growing risk and will be a bigger part of the litigation puzzle, unfortunately.’

In the EU, SLAPP lawsuits have already been identified as abusive litigation and new rules entered into force in autumn 2024 to support courts in dealing with them. These rules have been designed to ultimately deter claimants from filing SLAPP lawsuits against, among others, climate activists.

Developments in the climate litigation space are also important for progress in international climate talks. ‘There’s definitely a strong connection between political negotiation, climate talks and climate litigation’, says Klein. ‘Climate litigation is a tool to ensure that laws anchored in treaties like the Paris Agreement are adhered to. At the same time, litigation can contribute to shaping climate talks, because litigation itself raises awareness and creates political momentum which these negotiations respond to.’

The COP29 conference held in Azerbaijan, for example, featured a larger amount of side events focused on climate litigation. One such event assessed the growing integration of human rights within climate justice, while many attendants of the conference discussed the recent judgment by the Dutch Appeals Court, which overturned a ruling against Shell that had required the company to cut its emissions by 45 per cent by 2030 compared to 2019 levels.

Climate lawsuits often publicly lay bare the direct impact that the crisis is having on people, placing the spotlight on personal stories and highlighting the harms caused in a tangible way. This in turn provides fodder for international climate talks, which are often attended by activists, climate lawyers and those with personal climate harm experience. Climate litigation cases are also increasingly referred to in position papers submitted to the UN Framework Convention on Climate Change.

With COP30 to be hosted in the Brazilian Amazon city of Belém in November 2025, first-person accounts of the impact of the climate crisis will probably be featured more prominently than ever. Brazil has already stated that it wants to see the negotiations address the rights of Indigenous people.

Stepping stones

As much as litigation informs the direction of talks in this area, climate justice lawsuits most importantly influence each other. Next to the advisory opinions, the rulings in some recent cases – such as KlimaSeniorinnen – and upcoming judgments will shape the path for the next phase of lawsuits later in 2025. ‘Each case within this bubble of strategic litigation is like a stepping stone; they inspire each other’, says Germanwatch’s Klein. ‘There’s a kind of international inspiration happening in the field of strategic litigation, which is very important because we’re trying to trigger fundamental political change.’

By way of example, the ECtHR ruled in KlimaSeniorinnen that the state of Switzerland has an obligation to protect its citizens from the adverse effects of climate change and that it had failed to do so by inadequately limiting GHG emissions. The ECtHR thus linked the climate crisis to fundamental human rights.

The case has already been influential. The first climate litigation judgment handed down outside of Europe, by the Constitutional Court of Korea, mirrored some of the arguments found in the ECtHR’s ruling when it found parts of the country’s Carbon Neutrality Act unconstitutional. It looked, for example, at the state’s lack of intermediate carbon emissions mitigation planning and its failure to quantify a carbon budget.

Another recent judgment with global implications is the appeal ruling in Milieudefensie v Shell in the Netherlands. In November, the Hague Court of Appeal overturned a 2021 ruling that would have forced Shell to reduce its emissions by 45 per cent by the end of 2030 as compared with 2019 levels. It said that Shell cannot ‘be bound by a 45 per cent reduction standard (or any other percentage) agreed by climate science because this percentage does not apply to every country and every business sector individually’ and that there was no scientific consensus on a sectoral standard for the oil and gas sector.

However, the Court affirmed that companies such as Shell have a legal duty of care to curb GHG emissions based on international human rights law. ‘We are pleased with the court’s decision, which we believe is the right one for the global energy transition, the Netherlands and our company’, said Shell’s Chief Executive Officer Wael Sawan.

Environmental campaign group Milieudefensie has announced that it’ll take its case to the Supreme Court of the Netherlands. ‘The courts acknowledged that protection from climate change is a human right, that’s huge. It’s a very strong signal to the entire business community that climate litigation is still very much here and that they can’t just sit back and relax’, says Sjoukje van Oosterhout, Senior Team Lead at Milieudefensie in the climate case against Shell.

She adds that Milieudefensie has been in contact with many other climate litigation lawyers looking to bring, or having brought, lawsuits to courts. In the case of Asmania et al v Holcim, for example, lawyers were inspired by Milieudefensie’s case against Shell when they officially lodged their lawsuit in Switzerland in 2023. The lawsuit was brought by four inhabitants of the Indonesian island of Pari against Swiss building materials company Holcim, with the claimants alleging that the defendant is civilly liable for climate change-related damages on the island. The claimants seek compensation as well as a financial contribution to adaptation measures and a steeper reduction in Holcim’s GHG emissions. A Holcim spokesperson said the company takes climate action ‘very seriously’, adding that it ‘applies a rigorous science-driven approach to its net zero journey. In this decade of action, we are executing on our 2030 and 2050 1.5°C-aligned targets with speed and scale to decarbonise building across its lifecycle.’

Milieudefensie’s case against Shell follows 2015’s Urgenda, another globally significant case brought in the Netherlands and based on the duty of care argument. The ruling there, which was later upheld through various appeals procedures, obliged the Netherlands to make steeper GHG emissions reductions by 2020 in order to protect its citizens. ‘This generalised duty of care does not exist in other jurisdictions, it’s something very Dutch specific that makes the Netherlands a very good laboratory for these kinds of cases’, says Alberto Nicotina, a postdoctoral researcher in European law at University of Amsterdam, who’s assessing the consequences of strategic climate litigation for democracy.

The climate marathon

Thanks to the ruling in Milieudefensie v Shell, holding corporations accountable to human rights obligations is theoretically now valid in all jurisdictions that have signed the European Convention on Human Rights. ‘This endorses this principle of horizontal effect between a company and a person’, Douvartzidis says. ‘It interprets the UN Guiding Principles on Business and Human Rights and the OECD [Organisation for Economic Cooperation and Development] guidelines; to me, that is significant.’

‘The ruling has blasted the door open for future cases and provides instructions to lawyers on how to bolt on this indirect argument on fundamental rights on the impacts of climate change, because it recognises so significantly that protection from climate change is a human right’, she says.

Cases of individuals suing large companies underline the growing pressure that climate litigation is placing on corporate emitters. ‘Legal actions can result in stock price volatility, reduced investor confidence, and increased borrowing costs. Lawsuits, particularly those with high public visibility, can damage the reputation of companies, affecting customer loyalty and public trust’, says Luiz Zanchim, who’s a partner at SABZ Advogados in São Paulo.

‘Courts are starting to acknowledge the legal responsibility and accountability of large corporations, but this hasn’t yet resulted in concrete obligations. What needs to happen now is that a court actually says “this is what a corporation is obliged to do”’, says Germanwatch’s Klein.

Judicial activity has run in parallel with legislative action. For example, under the EU’s Corporate Sustainability Due Diligence Directive, which entered into force in July, large corporations are obliged to adopt a transition plan for climate crisis mitigation.

The importance of climate action – whether in the courts or in the boardroom – is now more frequently brought into focus than ever before, whether through the emergence of wildfires in the heart of Los Angeles or severe floods in the streets of Valencia. ‘We are playing Russian roulette with our planet. We need an exit ramp off the highway to climate hell, and the truth is we have control of the wheel’, warned UN Secretary General António Guterres.

Climate litigation is one tool in the box for activists to enforce change, but one that’s ‘a marathon, not a sprint’, says van Oosterhout. ‘That is something that a lot of people who work in climate litigation, and climate action in general, know and feel. I don’t think anyone ever expected that one day there’s going to be one agreement and then all of our climate problems will be fixed. We really have to take it one day at a time and look at all of the things that are going in the right direction.’

Karolin Schaps is a freelance journalist and can be contacted at karolin.schaps@magentamedia.eu

The IBA attended COP29 and coverage of its activities at the conference can be found here. The Association has also published updated guidance for lawyers on business and human rights, which can be viewed here.

Image credit: Adobestock.com