Reid Bryson, the founder in 1948 of a US research centre upon which CRU was modelled, was early in raising concerns about the impacts of climate cooling exacerbated by pollution. But he never switched to warming alarm and remained sceptical until he died in 2008.
Bryson, Reid A, and Thomas J Murray. Climates of Hunger: Mankind and the World’s Changing Weather. Madison; London: University of Wisconsin Press, 1977.