John W. Birks (born 10 December 1946, in Vinita, Oklahoma, USA) is an American atmospheric chemist and entrepreneur who is best known for co-discovery with Paul Crutzen of the potential atmospheric effects of nuclear war known as nuclear winter. His most recent awards include the 2019 Haagen-Smit Clean Air Award for his contributions to atmospheric chemistry and the 2022 Future of Life Award for discovery of the nuclear winter effect. As an entrepreneur, Birks co-founded the two technology companies, 2B Technologies and InDevR. At 2B Technologies he served as president during 2005-2020 and currently serves as Chief Scientist. Source: Wikipedia (en)