To mark the release of the sixth edition of our interactive climate change litigation map, our climate team reviews key developments from the last six months. We focus on new US entries, alongside developments in France and Germany.

Aaron Mandel, Partner in DAC Beachcroft’s New York office, comments:

“Climate litigation in the United States is shaped by a complex mix of factors: states and local governments suing fossil fuel companies, industry pushback, DOJ efforts to curb state action, challenging environmental findings, and long-running federal pre-emption questions. This potent mix explains why the United States has become a climate-litigation hotspot in recent months.”

Beyond the United States, a number of fossil fuel companies are using treaties and bilateral agreements to challenge European domestic climate policies that have adversely affected their investments. Notable arbitration proceedings are now underway in relation to abandoned fossil fuel projects in the UK and the Netherlands.

Europe also remains at the forefront of claimant-driven climate litigation. Two significant decisions are expected in France in the coming months, both examining how climate change intersects with the French Duty of Vigilance. A newly announced claim in Germany also seeks to build on Lliuya v RWE, where the court accepted in principle that major emitters could be liable under German civil law for climate-related harm occurring outside Germany.

US climate litigation reaches a critical juncture

As we move into the second half of the year, recent developments underline why the United States has emerged as a key climate litigation hotspot in 2026. Several significant cases have commenced in recent months, highlighting divergent approaches to climate policy across the country. The federal government, fossil fuel companies, and various cities and states are now engaged in a range of actions, often seeking to challenge one another’s positions.

Against that backdrop, US federal energy policy has taken a clear direction since the start of the second Trump administration. Shortly after inauguration, President Trump issued Executive Orders on Unleashing American Energy and Protecting American Energy from State Overreach. The latter order specifically targeted “illegitimate impediments” to domestic energy production, including state-level litigation and ‘superfund’ legislation.

The aims of state-level litigation or state-specific climate legislation are largely similar despite their differing foundations: both provide state governments with a process to recover from fossil fuel companies for the impacts of climate change within their borders. These approaches have generated scrutiny and challenge from both the Trump administration and those companies targeted.

State-level responses to climate change and associated litigation are not uniform across the United States. Some states, rather than pursuing litigation against fossil fuel companies, are implementing measures designed to shield fossil fuel companies from liability for climate-related damages.

In Utah, House Bill 222 (Limitation of Actions) was signed into law by the state's governor in March 2026. Those critical of the bill argue that it prevents the prospect of any successful litigation against polluters in the state. Similar legislation also has been advanced in other states, including Tennessee, Iowa, and Oklahoma.

Similar endeavours are underway in the Senate, with a number of senators introducing the Stop Climate Shakedowns Act in April 2026. According to the bill's sponsors, it intends to "prohibit frivolous climate lawsuits against American energy producers … in either state or federal court." If passed, the bill would pre-empt any attempt by states to regulate interstate and global emissions. Companion legislation also has been introduced in the House of Representatives. At the time of writing, it is not clear whether either bill is likely to pass, but its introduction emphasises the gulf in opposing outlooks across the US political spectrum.

As part of this wider push against climate-positive policy and litigation, the US Department of Justice (DOJ) brought four federal lawsuits against states in 2025. The actions against Vermont and New York challenged the legality of their climate 'superfund’ legislation, while the actions against Hawaii and Michigan sought to prevent those states from pursuing claims against fossil fuel companies in their own courts.

The Vermont case was argued earlier this year, and the New York action remains ongoing. By contrast, federal judges dismissed the DOJ’s actions against Hawaii and Michigan in early 2026. Hawaii responded to the dismissal of the DOJ's lawsuit by filing, the following day, its own proceedings against BP and other fossil fuel companies in state court. That case continues.

The Michigan action was dismissed in January 2026, shortly after the Michigan Attorney General issued a federal claim against several fossil fuel companies. Unlike other state-led cases, it advances antitrust causes of action under the Sherman Act, the Clayton Act, and the Michigan Antitrust Reform Act. It alleges a cartel operating in Michigan and nationally to restrain trade and suppress competition from renewables, contributing to higher household and transport costs for Michigan residents. Given its novelty, it remains one to watch and is included in this edition of the map.

The DOJ has not been deterred by these outcomes. After Michigan’s announcement, it argued that the litigation achieved its intended effect by prompting the state to drop its state-law claims and proceed in federal court. In early May 2026, the DOJ filed a further claim against Minnesota, seeking to block a longstanding climate-related action against several fossil fuel companies.

Federal pre-emption and the Endangerment Finding

For several years, US climate litigation has been shadowed by the prospect of Supreme Court guidance on whether federal law pre-empts state- or local government-led claims against fossil fuel companies brought under state laws.

Until recently, the Supreme Court repeatedly declined to hear arguments on federal pre-emption. For example, defendants petitioned the Court after the Hawaii Supreme Court, in City and County of Honolulu v Sunoco LP, allowed the case to proceed to trial. In 2024, the Court sought the US Solicitor General’s views; the Solicitor General said state courts were the appropriate forum, and the petition was refused.

However, in February 2026, the Court agreed to hear a petition brought by two major oil companies in relation to proceedings by the City of Boulder, Colorado. In 2025, the Colorado Supreme Court refused to dismiss Boulder’s claim, which alleges that fossil fuel companies misled the public about the risks associated with fossil fuels, in breach of state law.

The question presented to the Supreme Court is “Whether federal law precludes state-law claims seeking relief for injuries allegedly caused by the effects of interstate and international greenhouse-gas emissions on the global climate.” In short, the Court is being asked to define the scope of the “federal pre-emption” defence: that greenhouse gas (GHG) regulation falls within federal law (including the Clean Air Act) and therefore bars these state law claims.

The approach is not uniform across the states, and some state supreme courts have accepted the defence. In April 2026, for example, the Maryland Supreme Court dismissed three consolidated common law tort claims brought by local governments, holding they amounted to an attempt to regulate GHG emissions, a power reserved to federal law.

If it reaches the merits of the question presented, the Supreme Court’s decision could be pivotal for US climate litigation. Specifically, if it holds that federal law pre-empts these claims, defendants are likely to rely heavily on the ruling in seeking dismissal of similar actions. Its potential impact is why it features in this edition of the map.

But observers will have to wait: the Supreme Court is not scheduled to hear arguments in the Boulder case until its October 2026 term, and a decision may not be issued until June 2027. It also is possible the Supreme Court might not reach the question presented at all. The Court has directed the parties to brief and argue whether the Court has "statutory and Article III jurisdiction to hear this case." If the Court determines it lacks jurisdiction to hear the case, it will refuse to address the merits of the question presented.

Another complicating factor in US climate litigation is the February 2026 Environmental Protection Agency (EPA) announcement rescinding its 2009 Endangerment Finding. That finding concluded that current and projected concentrations of GHG emissions posed a threat to public health and welfare, thereby allowing the prescription of emissions standards for GHG. Following the rescission, the EPA states that it now "lacks statutory authority under Section 202(a) of the Clean Air Act to prescribe standards for GHG emissions."

The rescission itself is subject to challenge by a number of states, with the DOJ also continuing its own efforts to challenge state level litigation seeking climate-related damages. That lawsuit, Massachusetts and others v Environmental Protection Agency, will be an important action, justifying its inclusion on the map. We also expect that discussions on the interplay of the rescission of the Endangerment Finding and any Supreme Court ruling on federal pre-emption will develop in the coming months.

In the absence of the Endangerment Finding, some states may elect to establish and strengthen the regulation of GHG emissions standards within their borders. Taken together, these developments underscore why the United States is a key jurisdiction to watch in climate litigation.

Private companies use treaty provisions to challenge domestic policymaking

An addition to the previous edition of our map was an arbitration brought by, in part, a Singaporean investor (Woodhouse Investment Pte Ltd) under the Investor-State Dispute Settlement clause of a bilateral treaty between the UK and Singapore.

The arbitration followed the quashing of permission for a new coalmine in Cumbria. This action reflects supplemental comments made in the International Court of Justice as part of the landmark 2025 advisory opinion. The comments highlighted the tension inherent between ISDS clauses, investor rights and domestic policymaking efforts to challenge climate change. The Woodhouse action is ongoing. Although it does not feature on this version of the map, a similar Investor-State arbitration has recently been lodged in the International Centre for Settlement of Investment Disputes (ICSID) by Shell PLC against the Netherlands.

In 2024, the Netherlands approved the closure of the Groningen gas field to limit seismic risks in the area. The field was operated by a joint venture of Shell and ExxonMobil, both of whom have sought compensation for that decision. It is understood that a number of domestic and international arbitral proceedings related to the decision to close the Groningen gas field are ongoing.

Importantly, the most recent arbitration by Shell has been initiated before the ICSID under the Energy Charter Treaty (ECT). An international investment agreement in force since 1998, the ECT operates as a treaty intended to provide protection for energy investors across a number of states. Article 26 of the ECT provides an Investor-State Dispute Settlement (ISDS) clause allowing an investor to submit a dispute which cannot be settled amicably to an international arbitration body such as the ICSID.

Similar to those disputes in the Netherlands, it has also been recently announced that Landsdowne Oil and Gas PLC have registered a request with the ICSID for arbitration in a dispute over the Barryroe oil and gas field in Ireland.

Following the Paris Agreement and with nations looking to implement measures to phase out fossil fuels, several signatory states raised concerns that the ECT’s ISDS clause could deter climate action.

Simon Konsta, Partner in DAC Beachcroft's London office comments:

"For those countries that have withdrawn from the ECT, and those in the process of withdrawing such as Ireland, existing investments remain protected for another 20 years after withdrawal under the treaty's sunset clause. This leaves former signatory states vulnerable to arbitration long after their withdrawal, emphasising possible risks to states from investor-state dispute mechanisms as they seek to move away from fossil fuel projects. Corporates, particularly in carbon intensive industries, should be considering their potential exposure to climate measures and possible redress open to them, by whatever means available."

Corporate Duty of Vigilance: French cases near long-awaited judgments

France introduced a corporate Duty of Vigilance in 2017, requiring in-scope companies to introduce plans to identify and prevent serious violations related to human rights and fundamental freedoms, health and safety and the environment. Covering the activities of the companies but also their direct or indirect subsidiaries, subcontractors and suppliers, the law set the stage for the EU-wide Corporate Sustainability Due Diligence Directive. The law allows affected persons or organisations to seek injunctive relief requiring compliance with its obligations under the Duty, and compensation for damage.

In widening the potential scope for corporate liability, the Duty of Vigilance has prompted a range of climate-related claims, some of which have been subject to years of apparent inaction. Two of these claims are set to be decided in the coming months, making them priorities for inclusion in this edition of the map.

The first, brought against Total by a coalition of local authorities and non-governmental organisations, involves allegations that the company's current climate strategy is incompatible with its obligations under the Duty of Vigilance. Total disputes that the Duty applies to issues relating to climate change. Following the hearing in February 2026, this will be the first action in which the French courts will be asked to rule explicitly on the application of the Duty to climate change. The outcome, expected in June, will have considerable implications for corporate climate accountability, both in France and beyond.

The second action, pursued by a collection of Amazon indigenous communities and non-governmental organisations, led by Envol Vert, was commenced in 2021. Pursued against the French retail group Casino, well known for its supermarkets, the action alleges violations of human rights and environmental laws within Casino's supply chains in Brazil and Colombia in breach of the Duty of Vigilance. Cattle-industry generated deforestation linked to Casino's supply chains is alleged to have resulted in the destruction of forests. It is contended that these forests function as carbon sinks essential for combatting climate change.

Judgment is expected later this year. If the claim succeeds, it would be the first significant climate case to address a retailers’ responsibility for its supply chain impacts and the extraterritorial reach of the Duty of Vigilance.

More broadly, the concept of extraterritoriality in climate litigation continues to gain traction in Europe. We continue to monitor developments in the action of Casquero and others v Shell, an action issued in the UK High Court by members of Filipino communities affected by Typhoon Odette in 2021. This action is the first to seek a finding of direct liability on the part of a fossil fuel company for death and injury resulting from natural disasters in the Global South.

Alongside Casquero, the map now includes Laghari and others v Heidelberg Materials and RWE. Building on the principles established in Lliuya v RWE, this action seeks to hold German emitters liable for climate-related damages suffered by Pakistani farmers outside Germany.

Does this claim have a greater prospect of success? Arguably, yes. While Lliuya sought a contribution towards preventative measures to address the risk of a glacial lake flood or overflow, this claim concerns damage already suffered by the farmers during unprecedented rainfall in Pakistan in 2022. Similar to Lliuya, the action seeks a proportionate contribution to the damages suffered from RWE (an energy provider) and Heidelberg Materials (a concrete producer) based on their alleged contribution to global emissions. Materials provided by activists supporting the claim place these figures at 0.68% and 0.12%, respectively.

The Lliuya claim failed because the court found no concrete evidence of the alleged risk compelling the flood prevention measures. Laghari and others does not face the same obstacle in proving that damage has been suffered. It remains to be seen whether the court in Laghari will be willing to make positive findings on both the facts and corporate liability , and we will follow developments closely.

Small but significant: The year to date

So far in 2026, there have been only a handful of notable climate judgments, with outcomes cutting both ways for activists and affected communities.

In February, the Federal Court of Australia dismissed a greenwashing action alleging that the Australian energy company, Santos, had made misleading and deceptive representations within public statements, including climate strategies. As we reported, the judgment made clear that in Australia, findings of greenwashing require clear evidence of misleading or deceptive conduct or a failure to disclose material information to investors, or the absence of reasonable grounds for making representations about future matters. For corporates, the decision underscored the need for contemporaneous evidence to support representations made but also confirmed that a reasonable level of knowledge and awareness would be attributed to investors.

Building on the landmark European Court of Human Rights decision in Verein KlimaSeniorinnen, the Hague District Court in the Netherlands issued clarification on the treatment of overseas municipalities and territories in Greenpeace v State of the Netherlands.

Brought by activists on behalf of residents of Bonaire, a Caribbean island formally part of the Netherlands since 2010, the action alleged that the Netherlands had failed to protect the residents of the island from the effects of climate change. Finding in favour of the inhabitants of Bonaire, the court ordered the Netherlands to incorporate emission reductions targets for the entire economy, including implementing a specific adaptation plan for Bonaire by 2030.

Although the decision is not directly applicable to corporates or their insurers, it does emphasise the ambiguous regulatory environment for corporates. Courts demanding stronger domestic climate action will inevitably impact the regulation of corporates, including expected reductions in emissions. The announcement that both the ACCR v Santos and Bonaire actions will be the subject of appeals only serves to emphasise the uncertainty in which businesses and their insurers are operating when faced with climate-related litigation.

In late May, the United Nations General Assembly formally endorsed the landmark 2025 International Court of Justice opinion that member states have an obligation under international law to reduce greenhouse gas emissions. This endorsement does not compel member states countries to reduce their greenhouse gas emissions, as with the advisory opinion. However, it is reflective of the political will in many countries and will likely be relied upon by climate activists in support of their aims.

There is a clear push-pull across and within member states, their respective laws and treaties and international advisory opinions. The impact of those tensions, and any judicial decisions or further regulation generated, will continue to be of significant interest to corporates and their insurers.