Limiting climate change to the 1.5°C target set by the Paris Climate Agreement will likely require coal and gas power use to decline at rates that are unprecedented for any large country, finds an analysis of decadal episodes of fossil fuel decline in 105 countries between 1960 and 2018. Furthermore, the findings suggest that the most rapid historical cases of fossil fuel decline occurred when oil was replaced by coal, gas, or nuclear power in response to energy security threats of the 1970s and the 1980s.