A synthesis of compound weather and climate extremes in the Asian region, and implications for policy

On invitation from the World Climate Research Programme (WCRP), a collaborative team of climate scientists from across Asia has authored this concept paper to address the critical and escalating threat of “compound extreme events” in the Asian region.Human-induced climate change is accelerating, causing profound and widespread disruptions to our planet's interconnected systems from the atmosphere and oceans to land surfaces and the cryosphere. This has resulted in more frequent and intense extreme weather events globally. The IPCC has recently underscored the growing concern around the increased likelihood of compound extreme events, where multiple climate hazards occur simultaneously or in succession, dramatically amplifying risks. However, significant gaps remain in our understanding of the drivers and mechanisms behind these events.Asia is one the world’s most disaster-affected regions from weather, climate, and water-related hazards, arising from its unique geographical settings and regional climatic features including the seasonal monsoons. Therefore, an integrated understanding of how climate change will impact compound events in this region is essential for effective forewarning and risk mitigation.We analyse three key typologies of compound events illustrating their regional complexity and potential links to climate change:Compound Floods: We examine events like the devastating 2022 floods in the Indus River Basin, which were the result of a cascade of factors including intense pre-monsoon heatwaves, heavy monsoon rains, and accelerated glacier melt, along with modes of climate variability.Concurrent Heatwaves and Droughts: We explore the increasing prevalence of compound heatwave-drought events in East and South Asia, linked to large-scale drivers of the land-atmosphere-ocean coupled system, and local feedbacks. Marine Extremes: We investigate the compounding impacts of ocean warming, sea-level rise, marine heatwaves, and the intensification of tropical cyclones on Asia's extensive coastlines and marine ecosystems.By synthesizing the current state of knowledge in the Asian context, we identify critical knowledge gaps in our ability to understand and predict these complex events. We conclude with a set of actionable recommendations for advancing the science and technology needed to bridge these gaps. Our goal is to enhance the effective use of climate information to improve early warning systems and strengthen disaster risk reduction strategies across the region, ultimately building a more climate-resilient Asia.