Global Development Policy Center | 19 March 2026
Letter from 220 economists and legal scholars to Colombian President Gustavo Petro calling for action on ISDS
“Dear President Gustavo Petro Urrego,
We write to you as economists and legal scholars deeply concerned that investor-state dispute settlement (ISDS) poses a serious obstacle to building prosperous, equitable, and sustainable societies. As Colombia prepares to co-host the First International Conference on Transitioning Away from Fossil Fuels in Santa Marta from April 24-29, where discussions on ISDS will take the center stage, we urge you to seize the moment by giving effect to your decision to begin removing Colombia from ISDS,[1] and launching a broader alliance of countries committed to unwinding ISDS.
Written into thousands of international trade and investment treaties, including 18 agreements signed by Colombia, ISDS allows foreign corporations to bypass domestic courts and bring legal claims against host governments before special international arbitration tribunals that routinely award vast sums for alleged harms to their investments. ISDS is asymmetrical by design, granting foreign investors expansive protections that are unavailable to domestic businesses or citizens of the host country.
While proponents argue ISDS can protect investors from unfair treatment, in practice it has become a tool through which corporations can challenge non-discriminatory public policies on the basis that they affect corporate profitability, rather than because they discriminate against investors. This dynamic raises significant concerns about states’ ability to regulate freely in the public interest, including in the context of climate action.
The International Court of Justice has affirmed that states have an obligation, based on multiple sources of international law, to address climate change.[2] However, when governments take reasonable steps to address climate change – such as implementing fossil fuel phase-out measures – they have repeatedly been targeted by ISDS claims. For instance, your conference co-host, the Netherlands, is facing cases from ExxonMobil and Shell for closing the Groningen gas field.[3] For a country like Colombia, the risk is concrete. Under your leadership, the government has halted new fossil fuel exploration contracts and advanced an ambitious energy transition agenda[4]. Yet, Colombia has 129 oil and gas projects that are covered by ISDS provisions, exposing the country to claims in the billions of dollars.[5] As a report by the UN Special Rapporteur on Human Rights and the Environment warned, ISDS operates as a system for “paying polluters,” effectively requiring states to compensate corporations for complying with climate policies.[6]
ISDS has long been justified as necessary to attract foreign investment and thereby promote economic development. However, empirical evidence does not support any meaningful connection between ISDS commitments and increased investment inflows.[7] Brazil, South America’s largest recipient of foreign investment, has eschewed ISDS.
Colombia has a rare opportunity to scale back ISDS and ensure that it does not stand in the way of its transition away from fossil fuels – and it would not be charting this course alone. Across the world, governments are reassessing investment treaties and stepping back from ISDS. Countries such as South Africa, India, Indonesia, Ecuador, and Bolivia have terminated ISDS-enforced agreements after determining that they were not in their national interests. Even Global North countries that initially pushed ISDS in countless trade and investment agreements have been moving away from the regime. In North America, for example, the United States-Mexico-Canada Agreement eliminated ISDS between the United States and Canada and significantly narrowed it in relation to Mexico. Within the European Union, member states have terminated their mutual investment treaties, with nearly half also withdrawing from the Energy Charter Treaty, the largest multilateral agreement with ISDS, over concerns about its protection of fossil fuel investments.
Because ISDS is mostly treaty-based, durable reform cannot be purely unilateral. It requires coordination among states that recognize the structural contradiction between expansive investor protections and the rapid decarbonization demanded by science and international law. The Santa Marta conference provides a unique platform to initiate such coordination. By coupling Colombia’s domestic review of ISDS with an invitation to other governments to explore collective disengagement, you could help catalyze a coalition of countries working towards a world free of ISDS.
We urge you to use Colombia’s historic hosting of the First International Conference on Transitioning Away from Fossil Fuels as an opportunity to initiate steps toward withdrawing from ISDS and to galvanize coordinated international action, leaving a lasting legacy for others to follow.
Sincerely,
Joseph Stiglitz, Professor, Columbia University
Ha-Joon Chang, Professor, SOAS University of London
Thomas Piketty, Professor at the School of Economics and Co-Director of the World Inequality Lab
Jayati Ghosh, Professor, Department of Economics, University of Massachusetts at Amherst
David Boyd, Former UN Special Rapporteur on human rights and environment
M.Sornarajah, Emeritus Professor of Law, National University of Singapore
Jomo Kwame Sundaram, Emeritus Professor, University of Malaya
Laurence Tubiana, Dean of the Paris Climate School, Sciences Po
Kevin Gallagher, Director, Boston University Global Development Policy Center
Mark Weisbrot, Co-Director of the Center for Economic and Policy Research
Eileen Appelbaum, Co-Director of the Center for Economic and Policy Research
Andres Arauz, Center for Economic and Policy Research
Martín Guzmán, Professor, Columbia University School for International and Public Affairs
Rob Davies, Former Minister of Trade and Industry, South Africa
Isabella Weber, Professor, Department of Economics, University of Massachusetts Amherst
Philip Alston, Professor of Law, New York University
Jonathan Bonnitcha, Associate Professor, University of New South Wales
Juan Camilo Cárdenas, Professor, Department of Economics, Universidad de los Andes; Professor, Department of Economics, University of Massachusetts Amherst; Commissioner, Earth Commission
Robert H. Wade, London School of Economics
Richard Kozul-Wright, SOAS University of London
Rob Howse, New York University School of Law
Kyla Tienhaara, Associate Professor, School of Environmental Studies and Department of Global Development Studies, Queen’s University
David Abraham, University of Miami School of Law
Carlos Lozano Acosta, Comisión Mundial de Derecho Ambiental de IUCN.
Rafael Fernando Castro Alegría, Profesor y Analista de Derecho Internacional y Relaciones Internacionales
Donatella Alessandrini, Loughborough Law, UK
Alessandra Arcuri, Professor International Economic Law, Erasmus School of Law, Erasmus University Rotterdam
Michael Ash, Professor of Economics and Public Policy, University of Massachusetts Amherst
Harro van Asselt, Hatton Professor of Climate Law, University of Cambridge
Venkatesh Athreya, Adjunct Professor, Asian College of Journalism, Chennai, India
Brook K. Baker, Professor Emeritus Northeastern U. School of Law
Dean Baker, Center for Economic and Policy Research
Hendrik Van den Berg, University of Nebraska Lincoln and University of Massachusetts Amherst
Günseli Berik, Professor Emerita, University of Utah, USA
Geoffrey Bertram, Victoria University of Wellington, New Zealand
Sattwick Dey Biswas, Independent Researcher
Beryl Blaustone, Professor of Law Emerita, CUNY School of Law
Robert Blecker, American University (Emeritus)
Peter Bohmer, faculty, Emeritus in Economics and Political Economy, The Evergreen State College
Roger Even Bove, West Chester University (Retired)
Juan Carlos Moreno Brid, UNAM
Robin Broad, Research Professor, American University,
Julia Calvert
Jim Campen, Professor of Economics, Emeritus, University of Massachusetts Boston
Liam Campling, Queen Mary University of London
Sara Chandler KC(Hon), Human Rights Commission, European Bars Federation
C P Chandrasekhar
Kenneth Chay, Professor of Economics
Anuradha Chenoy
Carol Chomsky, University of Minnesota Law School
Cyra Akila Choudhury, FIU College of Law
Felipe Ford Cole, Boston College Law School
Lara Montesinos Coleman, Professor of International Law, Ethics and Political Economy, University of Sussex
Madison Condon, Associate Professor, Boston University School of Law
Christophe Courchesne, Associate Professor of Law, Vermont Law and Graduate School
Anthony P. D’Costa, University of Melbourne
Omar S. Dahi, Hampshire College
Dan Danielsen, Northeastern University School of Law
Byasdeb Dasgupta, Institute of Development Studies Kolkata (IDSK)
Steven Dean, Boston University School of Law
George DeMartino, University of Denver
Stephen Diamond, School of Law, Santa Clara University
David M. Driesen, Emeritus Professor, Syracuse University
Michael C. Duff, Professor of Law and Director, Wefel Center of Employment Law, Saint Louis University School of Law
Amitava Dutt, University of Notre Dame, Professor Emeritus
John Echeverria, Vermont Law and Graduate School
Christina Eckes, University of Amsterdam
William A. Edmundson, Regents’ Professor Emeritus, Georgia State University
Diane Elson, Emeritus Professor University of Essex
Gerald Epstein, University of Massachusetts Amherst
Eduardo Garzón Espinosa
Mads Falkenfleth, CEO of WELA
Eric M. Fink, Elon University School of Law
Kade Finnoff, Azim Premji University
Maria Floro
Nancy Folbre, University of Massachusetts Amherst
Andrew Foster, Duke Law School
Smitha Francis, Independent Researcher
Anders Fremstad, Economics Department, Colorado State University
Sakiko Fukuda-Parr, Professor of International Affairs, New School for Social Research
Claiton Fyock, University of Essex Law School
John Luke Gallup, Portland State University
Frank J. Garcia, Boston College Law School
Luciana Ghiotto, CONICET/UNSAM/TNI
Jean-Marc Gollier
Carmen G. Gonzalez, Loyola University Chicago School of Law
Neva Goodwin, Boston University Economics in Context
Jennifer M. Green, Clinical Professor of Law, University of Minneosta
Daphne T Greenwood, Professor Emerita, University of Colorado at Colorado Springs
David Singh Grewal, Professor of Law, UC Berkeley
Joyeeta Gupta, Professor Environment and Development in the Global South, University of Amsterdam
Teresina Gutierrez-Haces, Research Professor, Instituto de Investigaciones Económicas, UNAM, México
Michael Hamersky, Pace Energy and Climate Center
Martin Hart-Landsberg, Professor Emeritus of Economics at Lewis & Clark College
Jostein Hauge, University of Cambridge
Benton Heath, Temple University School of Law
James Heintz
Ralf Hepp, Fordham University
Mario R. Osorio Hernandez, Senior Fellow, Georgetown Law
Bill Ong Hing
Cynthia Ho, Loyola U. Chicago School of Law
Karyn Hollis, Villanova University
Todd Howland, Vermont Law and Graduate School
Michael Hudson, Emeritus Professor of Economics, UMKC
Chaumtoli Huq, CUNY School of Law
Tim Iglesias, University of San Francisco
Dr Gilad Isaacs, Executive Director, Institute for Economic Justice
Daniel Rangel Jurado, Rethink Trade
Fadhel Kaboub, Global Institute for Sustainable Prosperity
James L. Kainen, Fordham University School of Law
Jane Kelsey, Professor Emeritus, Faculty of Law, University of Auckland, New Zealand
Farida Chowdhury Khan, Professor of Economics, University of Colorado Colorado Springs
Mary King, Professor of Economics Emerita, Portland State University
Susan P. Koniak, Professor of Law Emerita
Jeanne Koopman
Laurence Kotlikoff, Professor of Economics, Boston University
Markus Krajewski, University of Erlangen-Nürnberg
Vincent Letellier, Maître de conférences à l’Université libre de Bruxelles
David S. Levine, Elon University School of Law
Ariana Levinson
Juan Camilo Sarmiento Lobo, Grupo de Trabajo Lex Mercatoria, poder corporativo y derechos humanos CLACSO
Arthur MacEwan, University of Massachusetts Boston
Tayyab Mahmud, Seattle University
Marisol Manfredi, University of Pisa
George de Martino, University of Denver
Thomas Masterson, Levy Economics Institute of Bard College
Alfred Dennis Mathewson
Carlos Sánchez Mato, Profesor economía aplicada Universidad Complutense de Madrid
Julie Matthaei, Wellesley College
Kathleen McAfee, Prof of law emeritus, New York Law School
Ladan Mehranvar, Columbia Center on Sustainable Investment
Martin Melkonian
Pablo Fajardo Mendoza
Carlin Meyer, Prof. Emerita, New York Law School
Marcelo Milan, Federal University of ABC, Brazil
John Miller, Professor of Economics Emeritus, Wheaton College
Oliver Morrissey, Professor of Development Economics, University of Nottingham
Federico Gutiérrez Naranjo, Universidad de Uppsala
Usha Natarajan, The University of the West Indies
Terrence Neal, Vermont Law & Graduate School
Julie Nelson, Emeritus Professor, Department of Economics, University of Massachusetts Boston
Peter Newell, Professor of International Relations, University of Sussex
Stephen Newman, Professor of Law Emeritus, New York Law School
José Antonio Ocampo, Professor, School of International and Public Affairs, Columbia University
Eva Paus, Mount Holyoke College, USA
Joergen Lindgaard Pedersen, DTU
Lorenzo Pellegrini, Professor, Erasmus University Rotterdam
Francisco Perez, University of Utah
Nicolás M Perrone, Professor, Universidad de Valparaíso
Peter Philips
Alberto Arroyo Picard
Zygmunt Jan Broël Plater, University of Maine School of Law; Boston College Law [ret.]
Willemien du Plessis
Robert Pollin, University of Massachusetts Amherst
James Gray Pope, Rutgers Law School
Stefano Prato, Society for International Development
Enrique Prieto-Rios, Profesor Facultad de Jurisprudencia Universidad del Rosario
Srividhya Ragavan, Professor of Law, Texas A&M University School of Law
Ali Raiss-Tousi, Anglia Ruskin University, London
Aziz Rana, J. Donald Monan, S.J., University Professor of Law and Government, Boston College
K S Chalapati Rao
Jacob Rask, Roskilde University
Rebecca Ray, Boston University Global Development Policy Center
Tahimí Suárez Rodríguez, Jurista
Malcolm Rogge, University of Exeter Law School
Naomi Roht-Arriaza, Distinguished Professor (emerita), University of California Law, San Francisco
Sonia E. Rolland, Northeastern University
Jon Romberg, Associate Professor, Seton Hall University School of Law
Bill Rosenberg, Economist, Visiting Scholar, Victoria University of Wellington Te Herenga Waka, New Zealand
Henning Grosse Ruse-Khan, Professor of Law, University of Cambridge
Michael Rustad, Suffolk University Law School
Lea Di Salvatore, the Center for Climate Change, Energy and Environmental law, the University of Eastern Finland
Alvaro Santos, Georgetown Law
András Schiffer, advocat, former MP (Hungary)
Ted P Schmidt, Professor Emeritus, Buffalo State University
Stephanie Seguino, University of Vermont
Theodore Seto, LMU Loyola Law School
James Silk, Clinical Professor Emeritus of Human Rights, Yale Law School
Penelope Simons, Professor, Faculty of Common Law and Director, Human Rights Research and Education Centre, University of Ottawa
Peter Skott, University and Massachusetts Amherst
Abbe Smith, Scott K. Ginsburg Professor of Law, Georgetown University
William Snape, Professor and Assistant Dean, American University, Washington College of Law
Mark Squillace, University of Colorado Law School
Irene van Staveren, professor of economics at Erasmus University Rotterdam
Rena Steinzor, Emerita Professor, University of Maryland Law School
Juliet P. Stumpf, Lewis & Clark Law School
Rafael Tamayo, Profesor Facultad de Jurisprudencia Universidad del Rosario
Zephyr Teachout, Fordham Law School
Rachel D. Thrasher, Boston University Global Development Policy Center
Chris Tilly, University of California Los Angeles
Daniel Titelman, Non Resident Senior Fellow, Global Development Policy Center
Mariano Treacy, CONICET-UNGS
Stephanie Triefus, Asser Institute
Silke Trommer, University of Manchester
Oscar Ugarteche, UNAM
Vamsi Vakulabharanam, Economics, University of Massachusetts Amherst
Tara Van Ho, St. Mary’s University (TX)
Pablo A. de la Vega M., Centro de Documentación en Derechos Humanos “Segundo Montes Mozo SJ” (CSMM)
Marco A. Velásquez-Ruiz, Academic and Consultant
Tara Van Ho, St. Mary’s University (TX)
Ingo Venzke, Professor, University of Amsterdam
Matias Vernengo, Bucknell University
Liza Vertinsky, Professor of Law, University of Maryland Francis King Carey School of Law
Magdalena Bas Vilizzio, Universidad de la República, Uruguay
Alejandro Villamar, Red Mexicana de Acción frente al Libre Comercio (RMALC),
Federica Violi, Erasmus University Rotterdam
Joan Vogel, Professor Emerita, Vermont Law and Graduate School
Norman Waitzman, Professor, Economics, University of Utah
David Whyte, Queen Mary University of London
Sue Willman KC (hon), Senior Lecturer, King’s Legal Clinic, King’s College, London
John Willoughby, Professor, Economics, American University
Lucas Wilson, Economics, Mount Holyoke
Peter Winship, professor emeritus, SMU
Chris Wold, Professor of Law, Lewis & Clark Law School
Martin H Wolfson, University of Notre Dame
John Womack, Harvard University
Brenda Wyss, Wheaton College Massachusetts
Alicia Ely Yamin, Harvard University
Anil Yilmaz Vastardis
Tai Young-Taft, Levy Economics Institute of Bard College
Gonzalo Fernández Ortiz de Zárate
Juan Hernández Zubizarreta, Profesor de la Universidad del País Vasco
Notes
[1] Colombia buscará renegociar los TLC con Estados Unidos y la Unión Europea en lo relacionado a laudos arbitrales. November 21, 2024, https://www.presidencia.gov.co/prensa/Paginas/Colombia-buscara-renegociar-los-TLC-con-Estados-Unidos-y-la-Union-Europea-en-lo-relacionado-a-laudos-arbitrales-241121.aspx
[2] International Court of Justice. Obligations of States in respect of Climate Change. Advisory Opinion, General List No. 187, 23 July 2025. https://www.icj-cij.org/sites/default/files/case-related/187/187-20250723-adv-01-00-en.pdf
[3] ExxonMobil Petroleum & Chemical BV v. Kingdom of the Netherlands, ICSID Case No. ARB/24/44; Shell PLC v. Kingdom of the Netherlands, ICSID Case No. ARB/26/2
[4] Luke Taylor, “Colombia announces halt on fossil fuel exploration for a greener economy,” The Guardian, (Jan 23, 2023)
[5] Hirschel-Burns, Tim, Rachel Thrasher, and Fiorella Paredes. 2025. “Defunding the Amazon. Mapping ISDS Risk From The Oil and Gas Sector in Amazonian Countries.” https://www.bu.edu/gdp/files/2025/11/GEGI-PB-032-FIN.pdf
[6] David R. Boyd, Special Rapporteur on the issue of human rights obligations relating to the enjoyment of a safe, clean, healthy and sustainable environment. 2023. “A/78/168 Paying polluters: the catastrophic consequences of investor-State dispute settlement for climate and environment action and human rights.” https://www.ohchr.org/en/documents/thematic-reports/a78168-paying-polluters-catastrophic-consequences-investor-state-dispute
[7] Brada, Josef C., Zdenek Drabek, and Ichiro Iwasaki. 2020. “Does Investor Protection Increase Foreign Direct Investment? A Meta-Analysis.” Journal of Economic Surveys 35(1): 34-70. https://onlinelibrary.wiley.com/doi/full/10.1111/joes.12392. See also Pohl, Joachim. 2018. “Societal benefits and costs of International Investment Agreements: A critical review of aspects and available empirical evidence,” OECD Working Papers on International Investment. https://www.oecd-ilibrary.org/finance-and-investment/societal-benefits-and-costs-of-international-investment-agreements_e5f85c3d-en
