Co-Chair, New York City Panel on Climate Change Co-Leader, Metropolitan East Coast Regional Assessment of the U.S. National Assessment of the Potential Consequences of Climate Variability and Change, sponsored by the U.S. Global Change Research Program Coordinating Lead Author of the IPCC Working Group II Fourth Assessment Report ("Observed Changes" chapter) Member, IPCC Task Group on Data and Scenarios for Impact and Climate Assessment Co-Editor, UCCRN First Assessment Report on Climate Change and Cities (ARC3). Panel member of the New York City Panel on Climate Change.