A study on the climate responses of East Asia due to air quality controls under climate change scenarios

This study investigates the impact of air quality controls on climate change in East Asia by analyzing two scenarios (SSP3-7.0 and SSP3-7.0-lowNTCF) provided by the AerChemMIP (Aerosols and Chemistry Model Intercomparison Project). The comparative analysis reveals that improvements in air quality are anticipated to result in further increases in both the annual mean temperature (+0.24K) and the frequency of the warmest day (TX90p; 7.7 additional days) by the mid-21st century (2045 ~ 2054) compared to the present-day climate (1995 ~ 2014). Similarly, the annual mean precipitation and extreme precipitation amount (R95p) are projected to increase by approximately 3.27% and 11.40% in mid-21st century, respectively. This implies that the air quality controls could potentially increase hydrological risks in the East Asia region. Therefore, it is essential to consider the potential negative impacts of environmental policies on the climate system during the policymaking process. Additionally, our results show clear evidence that the additional increases of mean and extreme temperature are primarily driven by fast response to reductions in NTCF (near-term climate forcer) emission. Furthermore, the horizontal distribution of additional warming is influenced by the local distribution of NTCF reductions over East Asia region. In contrast to temperature, the primarily climate responses of precipitation increases exhibit significantly depending on region. These findings reveal that the impacts of environmental policies on the climate system are nonlinear. Consequently, continuous research is essential, and this study is anticipated to serve as a valuable reference for further research and policy formulation.