Paul Mougeolle and Anne Stevignon helped craft a landmark climate lawsuit brought by French environmental nonprofit Notre Affaire à Tous and a handful of other NGOs against TotalEnergies. On June 25, a Paris court ruled that the oil and gas multinational violated its legal duty of vigilance by failing to account for emissions from the use of its products (so-called Scope 3 emissions), and ordered it to strengthen its vigilance plan. TotalEnergies is appealing. The lawsuit could provide a European template for holding fossil fuel companies accountable for their contributions to climate change.
What is the single most important action you think the public, or a specific company or government, needs to take in the next year to advance the climate agenda?
Paul Mougeolle: As recognized in the case we initiated, Notre Affaire à Tous et al. v. TotalEnergies, companies must adopt and implement effective climate transition plans. These plans are crucial to mitigating the most serious climate-related harm and keeping the objectives of the Paris Agreement within reach. They require corporate actors to demonstrate their best efforts to reduce emissions as quickly and deeply as possible, including by transitioning away from fossil fuels.
Anne Stévignon: Governments need to turn the fossil fuel phase-out from a political promise into an enforceable legal framework. That means ending the expansion of fossil fuel production, setting clear transition requirements for companies and financial institutions and ensuring that climate commitments can actually be enforced. We have spent years debating voluntary pledges. What we need now are binding rules that make the transition happen.
What is a climate solution that isn't getting the attention or funding it deserves?
Stévignon: An independent and well-funded climate civil society. Climate NGOs are rarely described as a "climate solution," but they are part of the infrastructure that makes climate action possible. They investigate, produce expertise, challenge misleading claims, bring cases before courts and hold governments and corporations accountable. At a time when climate organizations are facing severe funding pressures, weakening this counter-power would come at a very high cost.
What’s one sustainability effort you personally will try to adopt in the next year?
Mougeolle: I want to make a greater effort to reach out to people who do not share my views, and I hope environmental NGOs will do the same. Societal polarization is particularly problematic when it comes to climate change. I therefore think it is important to restore dialogue and look for common ground, rather than assuming that disagreement makes dialogue impossible. This is especially relevant in the legal context: Identifying areas of common ground has helped provide a basis for climate litigation. The scientific consensus on climate change, as reflected in the work of the Intergovernmental Panel on Climate Change, has informed the Paris climate goals, which in turn have become central to many climate cases. For me, sustainability also means finding ways to build broader support for climate action.
What gives you hope about the future of the planet?
Mougeolle: What gives me hope is that courts and the broader legal community are increasingly recognizing that traditional legal principles can be adapted to address the challenges posed by global warming. This is particularly visible in recent climate litigation and in the International Court of Justice’s 2025 advisory opinion on States’ obligations in relation to climate change. Climate litigation helps develop a legal framework in which governments and companies can be held accountable. Over time, these decisions can form a judicial architecture that complements the Paris Agreement and helps turn its objectives into concrete legal obligations.
Stévignon: I am not sure hope is what keeps the climate movement going. Persistence may matter more. Over the past decade, I have seen ideas once dismissed as radical or legally impossible enter courtrooms and become part of mainstream legal reasoning. This year, for instance, in a case we brought against TotalEnergies, a French court ordered the company to strengthen its climate vigilance plan, including measures addressing its indirect Scope 3 emissions. Companies are increasingly being asked to account for their full climate impact and to translate distant commitments into action now. Progress is painfully slow, but what is considered legally and politically possible does change, in part because people keep pushing when there is little reason to be optimistic.
