Europe’s Role in the World to Advance Climate Neutrality
26 November 2020
Independent Task Force on Creative Climate Action
28 May 2021

Roundtable on the Political Economy of Implementing Net Zero Emissions

The Roundtable took place on April 15, 2021.The event was co-hosted by the European Chair for Sustainable Development and Climate Transition of PSIA and School of Public Affairs at Sciences Po and by SIPA and Earth Institute/Climate School at Columbia University.

The Paris Agreement aims to limit global warming well below 2 degree Celsius, and preferably to 1.5 degree Celsius, compared to pre-industrial levels. A recent estimate suggests that net zero commitments by governments cover 60% of global greenhouse emissions, 68% of the global economy and over 50% of the global population. Targets are important to marshal action; they are the means to an end. However, a paucity of immediate action and focus of governments (and of companies) on distant targets suggests a real danger of targets becoming ends in themselves.

In this roundtable the speakers discussed ideas on the pragmatics of marshalling action to meet socially inclusive net zero global emission by 2050. In what ways can targets be usefully employed? What should be the nature of planning and of instruments including market mechanisms, industrial policies and tariffs? What forms of coalitions, respecting the principle of common but differentiated responsibilities and respective capabilities, would yield the most progress? What are some ways of leveraging differing political economies, governance forms and development unevenness to limit global warming?

Guest speakers

  • Scott Barrett, Vice Dean, School of International and Public Affairs (SIPA), Columbia University and Lenfest-Earth Institute Professor of Natural Resource Economics
  • Frannie Léautier, Senior Partner at SouthBridge Group and CEO of SouthBridge Investments, finance and development expert
  • Jeffrey Sachs, University Professor at Columbia University, Director of the UN Sustainable Development Solutions Network, Commissioner of the UN Broadband Commission for Development, SDG Advocate under UN Secretary-General António Guterres
  • Leena Srivastava, Deputy Director General for Science at the International Institute for Applied Systems Analysis (IIASA), former vice chancellor of the TERI School of Advanced Studies, New Delhi
  • Lola Vallejo, Climate Programme Director at IDDRI (Institut du Développement Durable et des Relations Internationales).


  • Alex Halliday, Director of the Earth Institute, Columbia University; Professor in the Department of Earth and Environmental Sciences
  • Shiv Someshwar, Head of the European Chair for Sustainable Development and Climate Transition at Sciences Po.


Dr. Scott Barrett

Barrett is the Vice Dean, School of International and Public Affairs, Columbia University and Lenfest-Earth Institute Professor of Natural Resource Economics. He is a leading scholar on transnational and global challenges, ranging from climate change to disease eradication. His research focuses on how institutions like customary law and treaties can be used to promote international cooperation. He has advised a number of international organizations, including the United Nations, the World Bank, the OECD, the European Commission, and the International Task Force on Global Public Goods. He was previously a lead author of the Intergovernmental Panel on Climate Change and a member of the Academic Panel to the Department of Environment in the UK.

Barrett previously taught at the Johns Hopkins University School of Advanced International Studies in Washington, D.C., where he also directed the International Policy program. Before that, he was on the faculty of the London Business School. He has also held visiting positions at Yale, Princeton, Université Paris 1 Panthéon-Sorbonne, the Institute for Advanced Study in Berlin, and École Polytechnique. Barrett is a research fellow with the Beijer Institute (Stockholm), CESifo (Munich), and the Kiel Institute of World Economics.

Dr. Alex Halliday 

Halliday is the Director of Columbia University’s Earth Institute, and professor in the Department of Earth and Environmental Sciences, since 2018. Prior to that he was at the University of Oxford as dean of science and engineering. 

Halliday is a pioneer in developing mass spectrometry to measure small isotopic variations in everything from meteorites to seawater to living organisms, helping to shed light on the birth and early development of our solar system, the interior workings of the Earth, and the processes that affect Earth’s surface environment. His scientific achievements have been recognized through numerous awards, including the Murchison Medal of the Geological Society, the Bowen Award and Hess Medal of the American Geophysical Union, the Urey Medal of the European Association of Geochemistry, the Oxburgh Medal of the Institute of Measurement and Control, and a Knighthood for services to science and innovation. He is a Fellow of the UK’s Royal Society and an International Member of the US National Academy of Sciences.     

Halliday has helped to lead a variety of distinguished scientific societies and advisory panels. He is the former Vice President of the Royal Society and former President of the Geochemical Society. He has served as an external board member for Britain’s Natural Environment Research Council, the Max Planck Society, London’s Natural History Museum, the American Geophysical Union, and more.

Dr. Frannie Léautier

Léautier, Senior Partner at SouthBridge Group and CEO of SouthBridge Investments, is a finance and development expert, with long-standing global experience leading and transforming organisations in the private, public and non-for-profit spheres. She has held various leadership roles at The Trade and Development Bank (TDB) Group, including TDB’s first Chief Operating Officer.  She also led the Asset Management business of TDB, including the launch of a unique product for trade finance in Africa. 

Léautier had an illustrious career at the World Bank Group (WBG), where during her 15-year tenure there, she held senior financial positions. She was Chief of Staff to the President, and served as Vice President for nearly seven years of her tenure at the WBG.  She was also Infrastructure Director and played a critical role in the strategic work around the joint World Bank/IFC infrastructure products and has played a crucial role in developing the World Bank Group’s infrastructure strategy.  While at the World Bank she won several awards for her outstanding support and contributions.  She was also Senior Vice President and Chief Operating Officer at the African Development Bank (AfDB) and chaired the Board of the AfDB.

Léautier was distinguished professor at Sciences Po Paris, and has lectured at MIT, Harvard and the University of Tokyo. She holds a MSc in Transportation and a PhD in Engineering (thesis on Infrastructure Systems) from MIT.  She also holds a doctorate in Humane Letters from North Central College and a doctorate in Law from Lancaster University, honoris causa. 

Dr. Jeffrey Sachs

Sachs is a University Professor at Columbia University, where he directed the Earth Institute from 2002 until 2016. He is director of the UN Sustainable Development Solutions Network and a commissioner of the UN Broadband Commission for Development. He has been advisor to three United Nations Secretaries-General, and currently serves as an SDG Advocate under Secretary-General Anto´nio Guterres. 

Sachs spent over twenty years as a professor at Harvard University, where he received his B.A., M.A., and Ph.D. degrees. He has authored numerous bestseller books. His most recent book is A New Foreign Policy: Beyond American Exceptionalism (2018). Sachs was twice named as Time magazine’s 100 most influential world leaders, and was ranked by The Economist among the top three most influential living economists. 

Dr. Shiv Someshwar

Someshwar is the European Chair for Sustainable Development and Climate Transition at Sciences Po, Paris. He leads multidisciplinary efforts on building development resilience to climate risks, and advises governments and multilateral institutions on identifying and implementing sustainable development action priorities in pursuit of Agenda 2030. Over the last decade and half, he has taught graduate level courses and conducted research at Columbia University on sustainable development and on climate change policies and risks. 

Someshwar’s publications cover a range of topics and issues: Planning and institutions for sustainable development; Climate change mitigation, adaptation and risks; and Ecosystem resilience and management. He is the editor of Re-living the memories of an Indian forester: Memoirs of S. Shyam Sunder (MUP, Feb. 2020). He is currently working on Realizing Development: Mismatch of research and institutions for action.

Someshwar has previously worked at the Earth Institute, Columbia University in New York, the Rockefeller Foundation in New York, and at the World Bank in Washington D.C. Someshwar has a Ph.D. in urban planning (with a focus on the environment) from the University of California, Los Angeles, and he was a Bell-MacArthur fellow at Harvard University.  He has two masters’ degrees on housing and environmental planning, and is also trained as a professional architect.

Dr. Leena Srivastava

Srivastava became Deputy Director General for Science at the International Institute for Applied Systems Analysis (IIASA) in November 2019. She was vice chancellor of the TERI School of Advanced Studies, New Delhi, an interdisciplinary higher education institution focused on sustainable development from 2012 to 2019. Prior to that, she worked for over three decades on research in the areas of energy, environment, and climate change policies at The Energy and Resources Institute (TERI), including for nine years as the executive director.

Srivastava co-chairs the Advisory Committee of Future Earth; is a member of the president’s advisory group on climate change and sustainable development at the Asian Development Bank; and member of the UN Technical Working Group on inclusive and just energy transitions for the High-Level Energy Dialogue 2021. Srivastava was the Coordinating Lead Author of ‘Working Group III’ of the Third Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) and the cross-cutting theme Anchor on “Sustainable Development” for its Fourth Assessment Report. She holds a master’s degree in Economics from the University of Hyderabad and a PhD in Energy Economics from the Indian Institute of Science in Bangalore, India.

Lola Vallejo

Vallejo is IDDRI’s climate programme director. Prior to joining IDDRI, Lola supported international climate negotiations as manager of the OECD-IEA Climate Change Expert Group and led the OECD work on climate-resilient infrastructure. She also assessed the UK’s adaptation policy as part of the national advisor and watchdog, the Committee on Climate Change. She also coordinated research on decarbonisation pathways at Imperial College London and worked as an environmental consultant in Paris.

Vallejo holds a finance Master’s degree from Science Po and an Msc in Environmental Technology from Imperial College.