Cumulative Harm as a Function of Carbon Emissions

Abstract

Anthropogenic climate change is indisputably harmful. Yet the nature, extent, and duration of this harm, and hence the extent of our individual and collective causal responsibility for it, are underappreciated. Climate disruption may persist for millennia, during which its harmful effects, lessened by adaptation and moderating temperatures, might diminish in frequency but will nevertheless continue to accumulate in number. Total harm can therefore be meaningfully estimated only relative to some specified time period. With regard to varying emissions scenarios, harm during any such time period within the next few millennia increases directly and (to a close approximation) continuously with cumulative prior anthropogenic carbon emissions up through that period. It follows that even small emissions can in the long run cause significant harm.