Martin L. Weitzman was a Research Professor of Economics at Harvard University until his untimely passing on August 27, 2019. Previously he was on the faculties of MIT and Yale. He had been elected as a fellow of the Econometric Society and the American Academy of Arts and Sciences. He published widely in many leading economic journals and written three books. Weitzman's interests in economics were broad and he served as consultant for several well-known organizations. His research is focused on environmental economics, including climate change, the economics of catastrophes, cost-benefit analysis, long-run discounting, green accounting, biodiversity, and comparison of alternative instruments for controlling pollution.