Air Pollution Interactions with Weather and Climate Extremes: Current Knowledge, Gaps, and Future Directions

During the past decade, weather and climate extremes, enhanced by climate change trends, have received tremendous attention because of their significant impacts on socio-economy, public health, and ecosystems. At the same time, many parts of the world still suffer from severe air pollution issues. However, whether and how air pollutants play a role in weather and climate systems through complex interactions and feedbacks with meteorology and ecosystems remains an open question. So far, only a relatively small number of studies have been conducted to understand and quantify air pollution interactions with weather and climate extremes. As a result, there is limited process-level knowledge of this topic and associated mechanisms. This review paper provides a concise synthesis of recent scientific advances, current knowledge gaps, and future directions on air pollution interactions with weather and climate extremes, such as extreme precipitation, floods, droughts, wildfires, and heat waves. There is evidence (albeit limited) that air pollution can contribute to or interact with each of the aforementioned extremes, and several possible mechanisms (e.g., physical, thermodynamical, dynamical, chemical, and ecological processes) have been identified and proposed to explain their relationships. However, there are still substantial knowledge gaps that need to be addressed in future studies, which will benefit from enhanced observational and modeling capabilities as well as interdisciplinary collaborations. Overall, the air pollution interactions with weather and climate extremes are currently under-studied and less understood. More future research is needed for process-level investigations to improve the mechanistic understanding on this topic.