This report synthesizes available fire history and climate change scientific knowledge to aid managers with fire decisions in the face of ongoing 21st Century climate change. Fire history and climate change (FHCC) have been ongoing for over 400 million years of Earth history, but increasing human influences during the Holocene epoch have changed both climate and fire regimes. We describe basic concepts of climate science and explain the causes of accelerating 21st Century climate change. Fire regimes and ecosystem classifications serve to unify ecological and climate factors influencing fire, and are useful for applying fire history and climate information to specific ecosystems. Variable and changing patterns of climate-fire interaction occur over different time and space scales that shape use of FHCC knowledge. Ecosystem differences in fire regimes, climate change and available fire history mean using an ecosystem specific view will be beneficial when applying FHCC knowledge.