The Climate Briefing

In this third instalment of the Future of Climate Diplomacy mini-series, Climate Briefing hosts Anna and Bhargabi explore what lessons that can be drawn from the history of the climate negotiations and how this can inform the future of climate diplomacy. To do this, they are joined by long-time COP researcher Dr Joanna Depledge (Research Fellow at the Centre for Environment, Energy and Natural Resource Governance and at Centre for Science and Policy, both at the University of Cambridge).

This week's Climate Briefing also includes a chat with Dr Patrick Schröder (Senior Research Fellow at Chatham House's Environment and Society Centre), who explains why the negotiations on a global plastics treaty are important and why the recent round of talks, once again, ended with no deal.

To find out more about the plastics treaty negotiations, see this piece in Foreign Policy by Patrick Schröder.

And to find out more about the proposal to introduce a voting rule at COP, see this piece by Dr Joanna Depledge.

On the 23rd of July 2025, the International Court of Justice (ICJ) issued its long-awaited Advisory Opinion on the obligations of states in respect to climate change. The Advisory Opinion makes clear that states have far-reaching obligations under international law to prevent harm to the climate system and that breaching such obligations could result in having to make reparations, among other things.

So, what impact might the ICJ's ruling have on international climate diplomacy and action, including climate-related litigation? To find out, Anna and Bhargabi speak to Dr Margaretha Wiwerinke-Singh, who is an Associate Professor of Sustainability Law at the University of Amsterdam and who lead the legal team of Vanuatu and the Melanesian Spearhead Group throughout the ICJ proceedings, and Dr Maria Antonia Tigre, who is the Director of Global Climate Change Litigation at the Sabin Centre at Columbia University.

To learn more about the ICJ's Advisory Opinion, read this Chatham House expert comment and/or listen to this Climate Briefing interview with Ralph Regenvanu, who at the time of the interview served as Vanuatu's Minister of Climate Change Adaptation, Meteorology and Geo-Hazards, Energy, Environment and Disaster Risk Management.

Ahead of the landmark COP30 in Belem, Brazil, this November, calls for reform of the UNFCCC and COPs are growing, as are concerns that the only formal global forum for climate negotiation and cooperation is under threat. In a series of conversations, Anna, Ruth and Bhargabi interview thought leaders in the climate world about what the future of climate diplomacy should look like.

The second guest in this mini-series is Kaveh Guilanpour, Vice President for International Strategies at C2ES, former lead of the UK's UNFCCC negotiations, co-lead negotiator for the EU, co-lead negotiator for the Alliance of Small Island States, and head of secretariat for the High Ambition Coalition, and senior advisor to the UNDG's Climate Action Team.

What happened at the 4th International Conference on Financing for Development (FFD4) and what does it mean for climate action? What are 'solidarity levies' and how might they help close the climate finance gap? What is needed to ensure someone actually reads the 'Baku to Belém Roadmap to 1.3T' after COP30?

To find answers to these and other burning climate finance-related questions, Anna speaks to Joe Thwaites (Senior Advocate, International Climate Finance, Natural Resources Defense Council) and Tom Evans (Senior Associate, Global Solidarity Levies Task Force).

To learn more about climate finance, please see these Chatham House outputs:

'Closing the climate finance gap: How to raise the money the world needs to support climate action' (research paper, available here)

'Taxing high-emitting sectors could help pay for climate-induced loss and damage' (expert comment, available here).

The 2025 edition of the June climate meetings in Bonn (formally 'the sixty-second sessions of the Subsidiary Body for Scientific and Technological Advice and the Subsidiary Body for Implementation of the UNFCCC', or 'SB62') took place 16 to 26 June. These meetings, which take place every year, constitute the only formal space for negotiations ahead of the COP, and are therefore very important.

In this episode of the Climate Briefing, Anna and Ruth speak to Alden Meyer (Senior Associate at E3G) and Catherine Abreu (Director of the International Climate Politics Hub) about what the main outcomes of the conference were, what the key sticking points were, and what it all means for COP30.

Climate litigation is both a strategic tool for climate action and an increasingly common part of the litigation landscape. Recent legal rulings have huge potential implications for the accountability and financial liability of big emitters, including both corporations and national governments.

Anna and Ruth talk to Joana Setzer, climate litigation and global environmental governance expert at London School of Economics' Grantham Research Institute. Joana explains the growth in climate litigation, describes landmark cases and tells us what we might expect from climate litigation in the future.

From plastic pollution to overfishing and climate change: the ocean is facing many severe threats. Sustainable Development Goal (SDG) 14 is focused on conserving and sustainably using the ocean and its resources. But what progress has been made in implementing this goal?

Ahead of the 3rd UN Ocean Conference, Anna speaks to Ambassador Peter Thomson (the UN Secretary-General's Special Envoy for the Ocean) about the state of the ocean, progress made in implementing SDG14, key next steps, and the potential of the UN conference to accelerate action.

Donald Trump's return to the White House poses serious challenges to climate change action and governance, but even before his second term began not nearly enough was being done to meet the goals of the Paris Agreement. In a series of conversations, Anna and Ruth interview thought leaders in the climate world about what the future of climate diplomacy should look like.

Their first guest in this new mini-series is Simon Sharpe (Managing Director of S-Curve Economics and author of 'Five Times Faster: Rethinking the Science, Economics and Diplomacy of Climate Change', with a previous career working on climate change issues within the UK Government).

Food systems contribute to around a third of global emissions and have a substantial impact on a range of other areas too, including biodiversity and human health. Transforming food systems is critical for meeting the goals of the Paris Agreement. But how should this be done in practice? To find out, Anna and Ruth speak to Emma Williams (Head of the Secretariat of the Alliance of Champions for Food Systems Transformation, ACF) and Richard King (Senior Research Fellow in the Environment and Society Centre of Chatham House).

To learn more about food systems transformation and related areas, please see the following Chatham House outputs:

• The research paper 'Aligning food systems with climate and biodiversity targets', available here.
• The report 'The emerging global crisis of land use', available here.

Increasingly severe climate change impacts are wreaking destruction across the world, with disastrous implications for human health, wellbeing, livelihoods, culture and security. How to deal with 'loss and damage' caused by climate change was for long a controversial topic within the UN climate negotiations, but at COP27 in 2022 governments agreed to establish a dedicated fund to assist developing countries in responding to the challenge.

In this episode of the Climate Briefing, Anna Aberg and Nina Jeffs (standing in for Ruth Townend) speak to Ibrahima Cheikh Diong, the Executive Director of the Fund for Responding to Loss and Damage, about what progress that has been made in operationalizing the fund, what lies ahead, what some of the main challenges are and how the fund interacts with the wider economic architecture.

To learn more about how loss and damage finance has featured in the climate negotiations, please see the Chatham House research paper 'Loss and damage finance in the climate negotiations: key challenges and next steps' (available here) and the expert comment 'The historic loss and damage fund' (available here).