Achieving the Paris Agreement necessitates massive low-carbon energy deployment. However, constructing, operating, and maintaining this system requires substantial energy, much of it from fossil fuels. This study calculates energy requirements and emissions for 14 mitigation pathways compatible with 1.5 °C warming. The initial transition likely causes a 10–34% net energy decline for society. Transition emissions are substantial (70–395 GtCO2, averaging 195 GtCO2), increasing the energy system's emissions share from 10% to 27% by 2050, potentially consuming the entire remaining emissions budget in some cases. The study suggests explicitly modeling energy system requirements and emissions in future low-carbon pathways.

Aljoša Slameršak, Giorgos Kallis, Daniel W. O'Neill