Definition of climatic optimum in US English:

climatic optimum

noun

  • 1A set of climatic conditions which are most favourable for a particular species or for human comfort and health (rare).

  • 2Palaeontology and Archaeology any of various historical or (usually) prehistoric periods characterized by comparatively warm and dry conditions compared to the preceding and following periods, specifically (also "Climatic Optimum") such a period which occurred in northern latitudes in the early Holocene, after the last glaciation (approx. 9000 to 5000 years ago, but varying with location).

Origin

Early 20th century; earliest use found in Frederic Edward Clements (1874–1945).