Climate Law Matters

A dive into the key trends and evolutions in global climate litigation, as set out in the Grantham Research Institute on Climate Change and the Environment's recent report, Global Trends in Climate Change Litigation: 2026 Snapshot. 39 Essex Chambers' barrister Ella Grodzinski talks to Catherine Higham, Senior Policy Fellow at the Grantham Research Institute, who co-authored the report.

They discuss the expansion and innovation of climate litigation across new regions, actors and legal strategies, the increasing complexity and interconnectedness of the field, and the growing pushback against climate action.

The full report and summary report can be accessed here.

39 Essex Chambers’ barrister Christopher Moss discusses climate attribution and the role it plays in litigation with Dr Matt Ösund-Ireland a partner at HKA with over 30 years’ of experience and a member of the Institution of Environmental Scientists and the Institution of Air Quality Management.

In this episode, Dr Ösund-Ireland explains what attribution science is, how it relates to the question of causation, and its relevance outside the litigation context. He further discusses the changing face of climate litigation and the role of an expert witness.

In this episode, Matthew McFeeley, a partner at Richard Buxton Solicitors discusses the legal implications of the Government’s drive for green energy with Celia Reynolds, a barrister at 39 Essex Chambers specialising in public and environmental law. Matthew and Celia discuss the changes introduced by the Planning and Infrastructure Act 2025, updates to the process for challenging DCOs, and the recommendations made in the Fingleton Review.

At the global level, it is estimated that aviation accounts for 2.4% of annual anthropogenic CO₂ emissions and 4% of anthropogenic global heating up to 2021. As the sector continues to grow, those impacts will increase, and by 2050, aviation could be responsible for around 22% of CO₂ emissions alone. In this episode, Steph David discusses the problem of emissions from aviation, how those emissions can be mitigated and the role the law can play in that mitigation with three experts in the field:

1. Ali Warrington, Head of Aviation, Energy and Heat at Possible, a climate campaigning organisation
2. Alex Chapman, Senior Economist at the New Economics Foundation leading up their programme on air transport and tourism
3. David Kay, Legal Director at Opportunity Green, an organisation focussing on bold and fair solutions to address climate change.

The panel discuss the current policy approach to decarbonise aviation, aviation taxation and legal barriers to its reform, the role of carbon pricing, the international nature of aviation and non-CO₂ emissions.

In the first episode of 2026, Ruth Chambers, Senior Fellow at Green Alliance returns to discuss the UK Government’s assessment of global biodiversity loss and ecosystem collapse with Flora Curtis, barrister at 39 Essex Chambers.

Published in January following an initially unsuccessful freedom of information request made in late 2025, the report examines the global ecosystems most critical to the UK and the risks that their collapse could pose to national security. Ruth explains the purpose of the assessment, its key findings, and what the impact of its publication has been both domestically and internationally.

In this special end-of-year episode, 39 Essex Chambers' barrister Ella Grodzinski and Anna Tranter of Irwin Mitchell look back at the key climate caselaw developments of the year.

Costs & Aarhus protections: 

• R (Badger Trust and Wild Justice) v Natural England [2025] EWHC 2761 (Admin)
• Green Lane Association v Central Bedfordshire Council [2025] EWHC 2251 (Admin)

Finch developments:

• Greenpeace Ltd & Uplift v Advocate General for Scotland [2025] CSOH 10
• R (Boswell) v Secretary of State for Energy Security and Net Zero [2025] EWCA Civ 669

Aviation: 

• R (Luton and District Association) v Secretary of State for Transport [2025] EWHC 3206 (Admin)
• R (Possible & Group for Action on Leeds Bradford Airport) v Secretary of State for Transport [2025] EWHC 1101 (Admin)

Additionally, they also share a look ahead to key cases in 2026, including the Foodrise Supreme Court appeal, Gatwick's second runway challenge, and emerging corporate accountability claims.

39 Essex Chambers' barrister Christopher Moss discusses the UK Emissions Trading Scheme (“UK ETS”) with Dr Diana Casey, the Executive Director of Energy and Climate change at the Mineral Products Association, a board member of the Emissions Trading Group, and chair of the Emissions Trading System Policy group for the Emissions Trading Group.

Dr Casey provides an overview of the UK ETS, its scope and purpose in achieving Net Zero before discussing opportunities and challenges, as well as how to measure the success of the UK ETS.

39 Essex Chambers' barrister Celia Reynolds talks to Professor Paul Fennell, professor of clean energy at the Department of Chemical Engineering, Imperial College London.

His work encompasses the decarbonisation and re-thinking of industrial processes, including the production of iron and steel and cement manufacture. He also works in the broader field of industrial decarbonisation, including synergies between industry and power generation.

In this episode, Professor Fennell provides an introduction to Carbon Capture, Utilisation and Storage (CCUS). He further discusses the challenges and opportunities for CCUS in the green energy transition.

39 Essex Chambers' barrister Flora Curtis talks to Nikki Reisch, Director of the Climate and Energy Programme at the Center for International Environmental Law, and Lucy Maxwell, Co-Director of the Climate Litigation Network, about the ICJ Advisory Opinion on climate change handed down on 23 July 2025. 

Nikki discusses the background to the case and its origins in the work of Pacific Island students. Nikki then discusses the ICJ's conclusion on whether the interpretive principle of lex specialis is relevant to States' climate change obligations. Lucy sets out the ICJ's key findings on the question of States' obligations under international law when it comes to the issue of climate change, both under the UNFCCC and the Paris Agreement and more broadly. Nikki and Lucy then discuss the Court's conclusions on the legal consequences for States who fail to comply with their international obligations on climate change, before considering the likely impact of the ICJ's decision.

Correction Note: At 25:19 “the State” should say “the Court”. At 28:17 and 38:41 Nikki’s observations were related to continued statehood in the face of sea level rise and not shifting maritime boundaries, reflective of the Court’s observation that sea level rise does not legally affect maritime boundaries or statehood. At 44:05, Nikki’s comment related to a request that has been made to the African Court on Human and Peoples’ Rights, not from which a request has been made.

Tessa Khan is the Executive Director at Uplift, a climate action organisation that supports efforts to transition rapidly and fairly away from oil and gas production in the UK. In this episode, she discusses a number of different legal developments to facilitate that transition, including the landmark legal case relating to the Jackdaw and Rosebank oil fields, following Sarah Finch’s successful case in the Supreme Court, as well as the new guidance, published last month, on how scope 3 emissions arising from the downstream combustion of the hydrocarbons should be assessed in the context of the proposed offshore oil and gas projects, and the potential role of the North Sea Transition Authority in facilitating that transition. She also sets out the role of litigation in shedding light on the windfall tax on the oil and gas industry.

 You can find out more about Uplift here: https://www.upliftuk.org/

You can access the Jackdaw and Rosebank decisions, here; the link to the Government’s new guidance on assessing scope 3 emissions, here; and the Government’s consultation on, among other things, NSTA’s principal objective in the Petroleum Act 1998, here.