This summary was prepared by the IBA Legal Policy & Research Unit (LPRU), with particular thanks to LPRU intern Precious Onuabuchi.

This year, 2025, marks ten years since Asghar Leghari successfully challenged the Pakistan government’s failure to implement its National Climate Change Policy. In its landmark decision, the Lahore High Court recognised that the Pakistan government’s inaction threatened the fundamental constitutional rights of its citizens and directed the establishment of Pakistan’s Climate Change Commission, setting in motion a raft of actions that have shaped Pakistan’s approaches to climate mitigation and adaptation to date. The decision has also helped to shape climate litigation across the globe, with courts in various jurisdictions adopting similar reasoning to hold governments accountable for climate inaction.

In recognition of this milestone, in September 2025, the IBA Environment, Health and Safety Law Committee,^[1] with support from the IBA Litigation Committee and the IBA Legal Policy & Research Unit, convened a webinar of legal experts including Asghar Leghari himself, to consider the impacts of the decision and the subsequent evolution of climate jurisprudence across the globe, including groundbreaking recent advisory opinions delivered by the International Court of Justice and Inter-American Court of Human Rights.

In this article, we highlight key moments from the discussion. Watch the full webinar here.

Climate litigation matters for every lawyer

In their opening remarks, Co-Moderators Ursula Zavala (Rodrigo Elias & Medrano Abogados; Climate Change Officer, Environment, Health and Safety Law Committee) and Rafael Pástor Vélez (Pérez Bustamante & Ponce; Publications Officer, Environment, Health and Safety Law Committee) stressed that climate litigation trends and their impacts are relevant to all lawyers, not only for litigators. The outcome of climate litigation influences policy formulation, statutory interpretation, human rights law, contractual framing and constitutional and administrative actions affecting governments, corporations, communities and future generations.

Climate change impacts threaten human rights and exacerbate vulnerabilities

Reflecting on what motivated him to commence proceedings in 2015, Asghar Leghari (PrimeLegalCo) highlighted that climate change disproportionately impacts vulnerable communities, and that government policies often fail to address the complex challenges that communities face: ‘I come from a family that relies on agriculture as a source of income. […] We are a water-scarce district.’

Francesco Sindico (Professor of International Environmental Law, the University of Strathclyde Law School; Chair, IUCN WCEL Climate Change Law Specialist Group) highlighted the importance of grounding climate change discussions in tangible realities, such as water scarcity. Joana Setzer (Associate Professor, Grantham Research Institute on Climate Change and the Environment at the London School of Economic and Political Sciences) concurred, emphasising that conversations about climate litigation must acknowledge the people and lawyers driving these cases: ‘This is not just about names and cases and courts from faraway places; this is about the lived experiences of individuals and the courage of lawyers who bring these cases.’

Leghari as a turning point for global climate litigation

Setzer described the Leghari v Pakistan decision as a turning point, humanising climate litigation and inspiring a surge of climate litigation that continues to this day. As of June 2025, almost 3,000 such cases had been filed across nearly 60 countries, with over 80 per cent of 2024 case filings being considered strategic. Like the Leghari case, over 120 of climate cases filed since 2015 challenge the ambition or implementation of government climate targets and policies.

The Leghari case has also proven significant as an early example of climate litigation in the Global South and has presided over a significant increase in cases, with – almost 60 per cent of cases recorded in the Global South filed since 2020. It also serves as a powerful example of using human rights as tool for advancing climate accountability. Setzer observed recent key developments in this space including the 2024 landmark Verein KlimaSeniorinnen Schweiz and Others v Switzerland decision,^[2] where the European Court of Human Rights affirmed states’ obligations to protect human rights against climate impacts.

New advisory opinions on climate change: another turning point for climate accountability?

Panellists agreed that this year’s advisory opinions on climate change from the International Court of Justice (ICJ)^[3] and Inter-American Court of Human Rights^[4] have profound implications – not just for states, but also for private actors and their legal advisors. The ICJ advisory opinion clarifies that states have an obligation under customary international law to protect the climate system and other parts of the environment from anthropogenic greenhouse gas emissions through regulation of public and private actors; and that failure of a state to take appropriate action to protect the climate system from greenhouse gas emissions – including through fossil fuel production, fossil fuel consumption, the granting of fossil fuel exploration licences or the provision of fossil fuel subsidies – may constitute an internationally wrongful act. Sindico observed that in light of these findings ‘it is impossible to justify the legality under international law of new or expanding old fossil fuel operations,’ and panellists foreshadowed that the opinion could trigger a wave of domestic climate litigation seeking to further clarify the obligations described by the ICJ.

Courts are just one piece of the puzzle: effective implementation needs political will and engagement from all actors

Leghari emphasised that while courts wield significant interpretive power in the realm of climate change, to have lasting impact their judgments require sustained implementation through political will and democratic engagement, and coordinated contributions from the judiciary, executive and legislature.

Citing D G Khan Cement Company v Government of Punjab,^[5] he noted that even in jurisdictions where courts have subordinated business rights to climate priorities, ensuring lasting political support for climate action remains a challenge. Sindico echoed these comments, observing that one of ‘the biggest elephants in the room’ is the reality that the impacts of climate change progress at a pace and scale misaligned with political systems.

In closing, the co-moderators stressed that everyone – including lawyers, governments, policymakers, corporations and communities – has a role to play in translating climate litigation outcomes into real-world action.