A typology of compound weather and climate events
- 1University of Bern, Climate and Environmental Physics, Bern, Switzerland (jakob.zscheischler@climate.unibe.ch)
- 2Oeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland
- 3Institute of Geography, Mobiliar Lab for Natural Risks, University of Bern, Bern, Switzerland
- 4School of Civil, Environmental and Mining Engineering, University of Adelaide, Adelaide, South Australia, Australia
- 5Department of Meteorology, University of Reading, Reading, UK
- 6Department of Earth and Environmental Sciences, Columbia University, New York, NY, USA
- 7Jet Propulsion Laboratory, Pasadena, CA, USA
- 8Deltares, Delft, The Netherlands
- 9Department of Civil and Environmental Engineering, University of California, Irvine, CA, USA
- 10LMD/IPSL, Ecole Normale Superieure, PSL research University, Paris, France
- 11Max Planck Institute for Biogeochemistry, Jena, Germany
- 12Wegener Center for Climate and Global Change, University of Graz, Graz, Austria
- 13Instituto Dom Luiz (IDL), Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal
- 14ARC Centre of Excellence for Climate Extremes, University of New South Wales, Sydney, Australia
- 15Department of Hydrology and Hydraulic Engineering, Vrije Universiteit Brussel, Brussels, Belgium
- 16Research Center for Statistics, University of Geneva, Geneva, Switzerland
Weather- and climate-related extreme events such as droughts, heatwaves and storms arise from interactions between complex sets of physical processes across multiple spatial and temporal scales, often overwhelming the capacity of natural and/or human systems to cope. In many cases, the greatest impacts arise through the ‘compounding’ effect of weather and climate-related drivers and/or hazards, where the scale of the impacts can be much greater than if any of the drivers or hazards occur in isolation; for instance, when a heavy precipitation falls on an already saturated soil causing a devastating flood. Compounding in this context refers to the amplification of an impact due to the occurrence of multiple drivers and/or hazards either because multiple hazards occur at the same time, previous climate conditions or weather events have increased a system’s vulnerability to a successive event, or spatially concurrent hazards lead to a regionally or globally integrated impact. More generally, compound weather and climate events refer to a combination of multiple climate drivers and/or hazards that contributes to societal or environmental risk.
Although many climate-related disasters are caused by compound events, our ability to understand, analyse and project these events and interactions between their drivers is still in its infancy. Here we review the current state of knowledge on compound events and propose a typology to synthesize the available literature and guide future research. We organize the highly diverse event types broadly along four main themes, namely preconditioned, multivariate, temporally compounding, and spatially compounding events. We highlight promising analytical approaches tailored to the different event types, which will aid future research and pave the way to a coherent framework for compound event analysis. We further illustrate how human-induced climate change affects different aspects of compound events, such as their frequency and intensity through variations in the mean, variability, and the dependence between their climatic drivers. Finally, we discuss the emergence of new types of events that may become highly relevant in a warmer climate.
How to cite: Zscheischler, J., Martius, O., Westra, S., Bevacqua, E., Raymond, C., Horton, R., van den Hurk, B., AghaKouchak, A., Jézéquel, A., Mahecha, M., Maraun, D., Ramos, A., Ridder, N., Thiery, W., and Vignotto, E.: A typology of compound weather and climate events, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-8572, https://doi.org/10.5194/egusphere-egu2020-8572, 2020.
