Mapping compound events for future climate risk
An international and interdisciplinary team scientists, among whom climate experts Philip Ward (IVM-VU) and Bart van den Hurk (KNMI), investigated better ways to map the interplay of circumstances surrounding extreme weather events. The work emphasises the need for a systemic research programme taking into account multi-factor compound events based on good documentation, analysis and model development.
For example, in January 2012, the region of Groningen was struggling with flooding. Normally, excess rain water is discharged into the Wadden Sea at low tide. In this case persistent northern winds kept pushing up water levels for almost three days, preventing the discharge of excess water during a period of heavy rain fall. The flooding in Groningen was thus caused by a combination of continuing high water and large amounts of precipitation.
Compound events such as these have drawn the attention of scientists and policy makers. When does an extreme weather event become a compound event? How do recognise the occurrence of such events in our data sets? Are they sufficiently included in current climate scenarios? How can we make our models and observations better suited to map compound events and link them to useful climate risk statements?
These questions have been addressed by a European team of climate scientists, statisticians and impact experts and published this week in Nature Climate Change. The paper describes a protocol to get a better grip on compound events by improving documentation, analysis and model development. Such a protocol will contribute to easier sharing of data on compound events between and within team of (inter)national climate researchers.
Jakob Zscheischler , Seth Westra, Bart J. J. M. van den Hurk, Sonia I. Seneviratne , Philip J. Ward, Andy Pitman, Amir AghaKouchak, David N. Bresch, Michael Leonard, Thomas Wahl and Xuebin Zhang (2018). Future climate risk from compound events. Nature Climate Change, vol. 8, p469–477.