Grantham Climate Litigation Guide 2

This guide, the second in a new series from the Grantham Research Institute at LSE and the Grantham Institute at Imperial College London, examines corporate defences used in climate litigation. Drawing on 10 climate litigation case studies from Europe, the United States and New Zealand, it analyses how corporate defendants have deployed these defence strategies, highlighting recurring themes and emerging trends. It also discusses how courts have engaged with these defence strategies.

Divided into three main parts, the guide provides legal practitioners, scholars and scientists with a systematic view of the legal arguments that are being used by corporate defendants.

• Part 1 introduces the defences used by corporate defendants in climate litigation.
• Part 2 discusses these defences in detail, providing examples from case studies.
• Part 3 examines how courts have engaged with corporate defences.

The guide concludes with a reflection on what these findings may mean for future climate litigation, and further details of the cases discussed.

Summary points

• Climate litigation against companies has increased over the last decade, with a growing number of cases filed seeking to hold private companies accountable for their alleged impacts on the climate. These include forward-looking corporate framework cases that seek to limit companies’ future emissions, as well as backward-looking polluter pays cases concerning liability for past emissions.
• Despite this increase in climate litigation, these legal actions have achieved only limited success. However, courts have begun to recognise, in principle, that companies may owe legal obligations to address climate change impacts caused by past emissions and to reduce future emissions.
• Academic literature has analysed global trends, legal duties and the role of scientific evidence in these cases. However, existing scholarship focuses primarily on claimant’ arguments, with much less systematic analysis of corporate responses to litigation. This guide aims to address this evidential gap.
• The authors analyse 10 climate litigation case studies from Europe, the United States and New Zealand, identifying recurring themes and emerging trends in the corporate defences used in these cases.
• As climate litigation has matured, corporate defences have expanded from broad objections about legal duty, responsibility and justiciability towards more technical challenges focused on climate science and causation. Courts have engaged with these defences at both legal and substantive levels, and judicial reasoning has increasingly considered developments in climate science.
• Some corporate defences have only had limited success. Arguments framing climate change as a diffuse societal problem beyond judicial reach have been rejected by courts in some instances, and courts have increasingly confirmed their jurisdiction to hear climate disputes against corporate defendants.
• However, other corporate defences have been more successful in influencing judicial decision-making. Arguments highlighting scientific uncertainty and defences relating to market substitution have in some cases been persuasive to courts when assessing corporate liability.

DOI: 10.21953/researchonline.lse.ac.uk.00138043

About the Grantham Climate Litigation Guides

These guides are a collaboration between the Grantham Research Institute at LSE and the Grantham Institute at Imperial College London. The series is designed to provide informed guidance on the use of climate science and evidence in legal and policy contexts in concise, non-technical language. Further guides will be published in 2026.