His work has enabled him to advise and collaborate with diverse organizations, including the Secretariat of the United Nations Framework Convention on Climate Change (UNFCCC), various United Nations and World Bank programmes, numerous government policy-making bodies and agencies, foundations, and civil society organizations throughout the developing and industrialized world.

He served as a Coordinating Lead Author in the preparation of the Fifth Assessment Report of the Intergovernmental Panel on Climate Change released in 2014, co-leading the chapter on Equity and Sustainable Development.

He received his Ph.D. in theoretical physics from Cornell University in 1993.