Pollution Trends over China Constrain Aerosol Forcing Simulated by CMIP6 Models

Abstract:

Aerosols play a unique role in the climate system by modifying Earth's energy budget. However, estimates of their climate forcing remain large uncertain. Here we found a noticeable decline trend of atmospheric absorption over eastern central China (ECC) in response to emission reductions, especially over the stringent control period of 2010-2018, and is consistent with a general decline of AAOD at available AERONET sites. Though all 15 CMIP6 models examined strongly underestimates the decline of both variables, the simulated trend of atmospheric absorption over ECC scales well with model estimated atmospheric forcing for industrial-era aerosols over East Asia. Applying the observed regional mean trend over ECC allows us to infer an atmospheric absorption of 12.83 Wm^-2 for industrial-era aerosols over East Asia. Our study quantifies the aerosol radiative forcing using a new constraint and provides evidence for a considerable warming induced by industrial-era aerosols.