Decadal trends of global climate and air pollution: two-way interactions, joint impacts and synergistic mitigation

Climate change and air pollution are arguably two most pressing environmental issues facing the world today. This talk gives an overview of recent studies relating the two at the decadal to multi-decadal time scale. The first part focusing on interactions will review recent works on how global warming affects aerosol distribution (Banks et al., 2021; Fiore et al., 2022), and in turn, how aerosols affect mean and extreme precipitation (Xu et al., 2022) and circulation changes (Diao and Xu, 2022), which could consequently impact air pollution itself (Wang et al., 2021), completing an intrinsic two-way feedback loop. The second part will address the joint occurrence of heat extremes and air pollution, including haze (Xu et al., 2020) and ozone (Xiao et al., 2022), raising awareness of their broader impact on human health and crop yield. Some concluding thoughts are given on how to mitigate the near-term warming rates by achieving co-benefits of air quality improvement (Ocko et al., 2021), while avoiding the temporary shock of aerosol unmasking (Dreyfus et al., 2022). A novel yet simple integrated human-Earth modeling framework is introduced to further demonstrate the importance of cutting non-CO2 pollutants to stabilize global warming (Xu and Ramanathan, in review).