Dr. Stephen Hammer is a globally recognized expert on climate policy and finance. He advises multilateral institutions worldwide and serves on international advisory committees for academic institutions across the United States, United Kingdom, and Egypt.
From 2023 to 2025, he helped launch the New York Climate Exchange, leading a coalition of academic, corporate, and community partners seeking to build a center for climate solutions—integrating research, education, innovation, workforce development, and finance to accelerate climate action at scale.
Previously, Dr. Hammer served as Senior Policy Advisor on international climate policy and strategy within the World Bank’s Climate Change Group. He advised senior leadership and represented the Bank in global forums on climate finance, including the UNFCCC Transitional Committee on the Loss and Damage Fund. He was instrumental in establishing the Coalition of Finance Ministers for Climate Action and chaired the MDB working group on Paris Alignment of lending portfolios in 2021.
Dr. Hammer joined the World Bank in 2013 as its first Global Lead for Cities and Climate Change. His work focused on urban resilience, low-carbon planning, and solid waste management in cities around the world. He helped launch key initiatives including the City Creditworthiness Initiative, the Low Carbon, Livable Cities (LC2) Initiative, and CURB, a scenario-based planning tool for city climate action.
Before joining the World Bank, he was a professor at MIT’s Department of Urban Studies and Planning and previously taught at Columbia University’s School of International and Public Affairs, where he founded and directed the Urban Energy Program. While at Columbia, Dr. Hammer co-founded and co-directed the Urban Climate Change Research Network (UCCRN) and served on the Energy Policy Task Force advising Mayor Michael Bloomberg on PlaNYC.
He holds a PhD from the London School of Economics, an MPP from Harvard Kennedy School, and a BS from the University of California, Davis.