A typology of compound weather and climate events

Abstract:

Compound weather and climate events refer to the combination of multiple drivers or hazards affecting societal or environmental risk. Many climate-related disasters are caused by compound events, yet their understanding, analysis, quantification and prediction is still in its infancy. Here we present a new typology of compound events to aid in their investigation. We organize the highly diverse compound event types according to four themes: preconditioned, where a weather-driven or climate-driven precondition aggravates the impacts of a hazard; multivariate, where multiple drivers and/or hazards lead to an impact; temporally compounding, where a succession of hazards leads to an impact; and spatially compounding, where hazards in multiple connected locations cause an aggregated impact. Through structuring compound events and their respective analysis tools, the typology offers an opportunity for deeper insight into their mechanisms and impacts, benefiting the development of effective adaptation strategies. We illustrate each class with real-world examples and identify avenues for future research to improve our understanding of compound events under present and future climate conditions.