Mitigation choices impact carbon budget size compatible with low temperature goals

Abstract

Global-mean temperature increase isroughly proportionalto cumulative emissions of carbon dioxide (CO2). Limiting global warming toany level thus implies a finite CO2budget. Due to geophysical uncertainties, the size of such budgets can only be expressed in probabilistic terms and is further influenced by non-CO2emissions. We here explore how societal choices related to energy demand and specific mitigation options influence the size of carbon budgets for meetingagiven temperature objective. We find that choices that exclude specific CO2mitigation technologies (like Carbon Capture and Storage) result in greater costs, smaller compatible CO2budgets until 2050, but larger CO2budgets until 2100...