Reduced emissions through climate damage to the economy

Abstract

Today, most global economic production depends on energy produced from burning fossil fuels, which emit carbon dioxide as a byproduct. Although the costs of carbon-free energy such as wind and solar have come down dramatically over recent decades, there are substantial challenges to completely decarbonizing our electricity system, and even greater challenges to completely decarbonizing the transportation and industrial sectors (1). Thus, economic activity is projected to produce greenhouse gas emissions throughout this century. These emissions of greenhouse gases are causing Earth to warm, and, in aggregate, the effects of global warming are expected to be deleterious. These deleterious effects are expected to harm global welfare and diminish economic productivity. This diminution of production, other things being equal, would lead to a reduction in greenhouse gas emissions and, thus, would lessen the anticipated warming. In PNAS, Woodard et al. (2) find that the reduction in emissions through damage to economic activity is roughly the same magnitude as, but opposite in sign to, natural carbon cycle feedbacks that are projected to increase carbon dioxide levels relative to a world without carbon–climate feedbacks. The net effect of the socioeconomic carbon–climate feedbacks is estimated to be about the same magnitude as, but opposite in sign to, natural biogeophysical carbon–climate feedbacks. As a result, the level of greenhouse gases in the atmosphere in 2100 is projected to be about the same as if neither feedback (socioeconomic or natural biogeophysical) were active. Woodard et al. (2) analyze various influences on carbon dioxide emissions using the Kaya identity, which represents these emissions as the product of population, per-capita productivity, energy used per unit of production [energy intensity of gross domestic production (GDP)], and carbon emitted per unit of energy used (carbon intensity of energy). Reduced per-capita economic productivity due to climate change is projected to be … [↵][1]1To whom correspondence should be addressed. Email: kcaldeira{at}carnegiescience.edu. [1]: #xref-corresp-1-1