Carbon emissions—and hence fossil fuel combustion—must decline rapidly if warming is to be held below 1.5 or 2 °C. Yet fossil fuels are so deeply entrenched in the broader economy that a rapid transition poses the challenge of significant transitional disruption. 

The principles and framework laid out here are offered as a contribution to understanding the nature of the potential impacts of a transition, principles for equitably sharing the costs of avoiding them, and guidance for prioritizing which fossil resources can still be extracted.