Stephen Hammer, PhD

Dr. Stephen Hammer was selected as the Founding CEO of The New York Climate Exchange in November of 2023. As CEO, Dr. Hammer will lead a first-of-its-kind collaborative model for accelerating climate change solutions for New York City and beyond.

As one of the world’s leading experts on both local and global climate policy matters, Dr. Hammer brings more than thirty years of experience to this role. Prior to joining The Exchange, Dr. Hammer spent a decade at the World Bank where he served as Senior Policy Advisor on urban scale climate solutions and global climate policy and finance issues. He spearheaded much of the Bank’s early work on urban climate resilience, the modeling of low carbon development, and capacity building, and supported the rollout of efforts to mainstream climate change into all facets of the Bank’s lending operations. As a strategic advisor to senior management, he oversaw many of the Bank’s key climate partnerships with the UNFCCC, the UN Secretary General’s team, and the G20. Dr. Hammer regularly represented the Bank in international for a, most recently supporting the work of the UNFCCC’s Transitional Committee charged with establishing the new global fund on Loss and Damage that was a key outcome at COP27.

Before joining the World Bank, Dr. Hammer was a professor at MIT’s Department of Urban Studies and Planning (DUSP), where he taught courses and conducted research on a variety of urban energy and climate policy topics including local energy policymaking, urban energy systems, distributed generation, and the impacts of climate change on local and regional energy networks. Prior to that, he taught climate courses in New York City at Columbia University’s School of International and Public Affairs and at the Pratt Institute.

Dr. Hammer co-founded and co-directed the Urban Climate Change Research Network (UCCRN), an international consortium of researchers interested in climate change from an urban perspective. He was also a member of the Energy Policy Task Force advising then-Mayor Michael Bloomberg on PlaNYC, the City’s long-term growth and sustainability initiative. He is an Advisory Board Member for the American Geophysical Union task force on Ethical Framework for Climate Interventions and the Climate and Clean Air Coalition.

Dr. Hammer holds a Ph.D. from the London School of Economics, an MPP from the Kennedy School of Government at Harvard University, and a B.S. in Environmental Policy Analysis and Planning from the University of California at Davis. He is thrilled to return to New York, where he previously lived for over 25 years, to spearhead the vision of The Exchange.