Leonardo Martinez-Diaz is senior fellow and director of the Sustainability, Climate, and Geopolitics Program at the Carnegie Endowment for International Peace. His fields of expertise include climate politics and diplomacy, climate finance, and mitigating and managing the risks of climate change to economies and communities.

Prior to joining Carnegie, Martinez-Diaz led the climate finance team in the Office of the Special Presidential Envoy for Climate at the U.S. State Department, where he helped oversee the largest expansion of U.S. support for climate investments in developing countries. In 2024, President Biden nominated Martinez-Diaz to serve as Executive Director for the United States on the board of the World Bank Group. 

From 2017-21, Martinez-Diaz directed the Sustainable Finance Center at the World Resources Institute, where he led a team of researchers investigating the carbon intensity of China’s Belt and Road Initiative, the green finance commitments of some the world’s biggest banks, and the design of institutions that provide disaster risk insurance to developing countries.  

Martinez-Diaz also served on the Climate-Related Market Risk Subcommittee of the U.S. Commodity Futures Trading Commission, where he co-edited a key report on managing climate risk. Martinez-Diaz served in the federal government from 2010-2016 in senior positions working on climate diplomacy and development. At the U.S. Agency for International Development, he directed the Agency’s newly-reconstituted policy office, and at the U.S. Treasury Department, he served as Deputy Assistant Secretary for the Western Hemisphere and later for Energy and Environment, where he led the department's climate finance portfolio. He represented the United States on the boards of several institutions, including the Green Climate Fund and the Global Environment Facility. He was also part of the U.S. delegation that negotiated the 2015 Paris Agreement on climate change.

Before his government experience, Martinez-Diaz worked as a scholar, author, and consultant, specializing in the governance of international financial institutions.  He was a fellow at the Brookings Institution’s Global Economy and Development Program and a consultant for the World Bank’s Commission to Reform World Bank Governance and the IMF’s Independent Evaluation Office.           

Martinez-Diaz is author, co-author, and editor of many books and articles including Building a Resilient Tomorrow: Preparing for the Coming Climate Disruption (Oxford University Press, 2019 and 2022); Globalizing in Hard Times: The Politics of Banking-Sector Opening in the Emerging World (Cornell University Press, 2009), and Networks of Influence? Developing Countries in a Networked Global Order (Oxford University Press, 2009).