ASIL Task Force on Investor-State Dispute Settlement (ISDS) and Climate Change

The intersection of climate change and international investment law presents a complex challenge for the global legal community. As States adopt climate policies to meet international commitments and address the climate emergency, foreign investors who may be affected by those measures, can invoke protections under investment treaties.  With States phasing out fossil fuels and incentivizing renewable energy, the likelihood of investment disputes arising from climate-related regulations is expected to grow.

And yet, the legal questions surrounding Investor State Dispute Settlement (ISDS) and climate change remain largely unresolved. While investment tribunals have encountered environmental regulations in past disputes, tribunals have not comprehensively addressed the balance between investor protection and State climate obligations.  Further, to-date no systematic effort has been made to clarify how international climate change obligations interact with investment treaty protections, including the impact of the framework relevant to climate change on the complex relationship between foreign investors and host States.  At the same time, the global international legal landscape is evolving rapidly.  The International Court of Justice (ICJ), the Inter-American Court of Human Rights (IACtHR), and the International Tribunal for the Law of the Sea (ITLOS) have been called upon to clarify State obligations concerning climate change.  Their opinions may shape how international law is applied in investment disputes.

In response to this evolving landscape, the American Society of International Law (ASIL) created the Task Force on Investor-State Dispute Settlement (ISDS) and Climate Change, chaired by Chiara Giorgetti, Mairée Uran Bidegain and Janet Whittaker.  The Task Force brings together leading experts to analyze the substantive and procedural issues surrounding climate-related investment disputes.

Mission and Objectives

The evolving intersection of ISDS and climate law has significant implications for the broader international legal community, creating an imperative to develop clear and concrete guidelines.  By leveraging insights from international law, arbitration practice, climate science, and economic frameworks, the Task Force aims to provide stakeholders—including States, investors, arbitrators, civil society, and legal practitioners—with practical tools and guidance to navigate ISDS cases involving climate measures, both in terms of substance and procedure.

The ASIL Task Force on ISDS and Climate Change is committed to:

  • Engaging with stakeholders to foster coherence in interpreting the international law regimes at the intersection of climate change and investment protections. 
  • Developing guidance on tools available to the ISDS community to interpret and apply investment treaty standards considering climate obligations.
  • Examining the impact of international courts’ climate change advisory opinions on ISDS cases.
  • Analyzing evidentiary and causation challenges in climate-related ISDS cases, including the role of attribution science.
  • Identifying best practices for quantifying damages in disputes involving climate-related regulation.

The Task Force’s goal is to draft a Report addressing these issues to be presented at the 2027 ASIL Annual Meeting. The Task Force also aims to promote awareness among the ISDS community of the legal, scientific, and economic dimensions of climate change, as well as to engage in outreach with the ASIL and broader international law community on relevant issues. 

Task Force Leadership and Members

The Task Force comprises a renowned and diverse group of legal practitioners, arbitrators, State representatives, academics, scientists, and civil society members committed to advancing the understanding of climate-related investment disputes.
Members include:

  • Chiara Giorgetti (Professor Richmond Law School, Senior Fellow International Claims and Reparations Project at Columbia Law School and Vice Chair of the Board of the Register of Damages for Ukraine. Co-chair)
  • Mairée Uran Bidegain (Independent Arbitrator and Consultant, Co-Chair)
  • Janet Whittaker(Clifford Chance LLP and Arbitrator, Co-Chair)
  • Laurence Boisson de Chazournes (Independent Arbitrator; Professor of International Law, University of Geneva)
  • Sam Bookman (Climate Law Scholar & Practitioner, Sabin Center for Climate Change Law)
  • Zachary Douglas KC (Independent Arbitrator, Barrister, 3 Verulam Buildings; Professor International Law, Graduate Institute, Geneva, Director of the LL.M. in International Dispute Settlement (MIDS))
  • Sergio Diaz (Head of the Treaty Section, Ministry of Foreign Affairs, Colombia)
  • Martin Doe (Deputy Secretary-General and Principal Legal Counsel, Permanent Court of Arbitration (PCA))
  • Annette Magnusson (Founder, Climate Change Counsel; Former Secretary General, SCC Arbitration Institute)
  • Sara Marzal (Legal Counsel, International Centre for Settlement of Investment Disputes (ICSID))
  • Petra Minnerop (Professor of International Law, Durham University; Founding Director of the Durham Centre for Sustainable Development Law and Policy)
  • Harj Narulla (Barrister, Climate Law and Litigation, Doughty Street Chambers; Visiting Senior Fellow in Climate Law and litigation, Grantham Research Institute on Climate Change and the Environment, LSE)
  • Nilufer Oral (Director of the Centre of International Law at the National University of Singapore; member UN International Law Commission (ILC) Co-chair of the ILC Study Group on sea-level rise in relation to international law)
  • Friederike Otto (Senior Lecturer in Climate Science, Centre for Environmental Policy, Imperial College London; Intergovernmental Panel on Climate Change (IPCC) Sixth Assessment Report Author; leader, World Weather Attribution)
  • Martins Paparinskis (Professor of Public International Law, University College London (UCL); Member, UN International Law Commission (ILC))
  • Franz Perrez (Ambassador, Director General, Directorate of International Law, Federal Department of Foreign Affairs, Switzerland)
  • Nikki Reisch (Director, Climate & Energy Program, Center for International Environmental Law (CIEL))
  • Arman Sar varian (Of Counsel, Albertson Law, Reader in Public International Law, University of Surrey; UK; Humboldt Research Fellow in Climate Change Law, University of Kiel, Germany)
  • Jeremy Sharpe (Independent Arbitrator; Visiting Professor at National University of Singapore; former Chief of Investment Arbitration in the Office of the Legal Adviser at the U.S. Department of State)
  • Lee-Anne Sackett (Legal Affairs Manager, Climate Justice & Diplomacy Program, Vanuatu)
  • Sylvie Tabet (General Counsel and Director, Trade Law Bureau, Government of Canada)
  • Jorge Viñuales (Independent Arbitrator; Professor of Law and Environmental Policy, University of Cambridge; Founding Director of the Cambridge Centre for Environment, Energy and Natural Resource Governance)
  • Cristina Voigt (Professor, University of Oslo; Co-chair of the Paris Agreement´s Compliance and Implementation Committee; Chair of the IUCN World Commission on Environmental Law)

Engagement and Next Steps

The Task Force provides a forum for meaningful engagement on the pressing issue of ISDS and climate change.  By integrating insights from investment law, climate science, and broader international legal frameworks, the Task Force will serve as a pivotal resource for all stakeholders navigating the future of ISDS in a climate-impacted world.

The Task Force welcomes engagement from across the international legal community.  Stakeholders are encouraged to participate in discussions, contribute expertise, and provide feedback on the Task Force´s work. [For more information or to express interest in contributing, please contact [email]

Upcoming Events and Timeline

  • The Task Force will hold a launch event at the 2025 ASIL Annual Meeting in Washington, D.C.
  • A comprehensive Report addressing key issues will be presented at the 2027 ASIL Annual Meeting.