First attested in the 1950s. Came into common use in the mid-1970s with Wallace Smith Broecker's paper "Climatic Change: Are We on the Brink of a Pronounced Global Warming?" (1975) and Mikhail Budyko's statement in 1976 that "a global warming up has started".
May be treated as a synonym of climate change in informal contexts, particularly in regions where climate science is contested by political actors. This conflation is not widespread in scientific contexts, where it may be regarded as incorrect.