A socio-economic crisis was added to the Intergovernmental Panel on Climate Change (IPCC) Representative Concentration Pathway 8.5 (RCP8.5) scenario. This idealized climate scenario was simulated using the Community Earth System Model version 1.2.2 to determine the transient climate response to a two-year reduction of anthropogenic emissions. Global and regional (Asian, North American and European) mean surface temperatures (MSTs) were significantly warmer than baseline for 5 years. This was followed by cooler-than-baseline MSTs lasting for about two decades until the end of the simulation. Emission reduction of only carbon dioxide (CO2) resulted in multi-decadal cooler-than-baseline MSTs. Emission reduction of aerosols and aerosol precursors resulted in strong short-term warmer-than-baseline MSTs for the first five years after the start of the crisis. This was followed by weaker multi-decadal warmer-than-baseline MSTs. The greatest warming occurred over Europe. This could be explained by the inter-scenario differences in the state of the North Atlantic Oscillation. However, global, Asian and North American MSTs were all warmer than baseline.
Field of science