The Climate Crisis role
Scientific literature stated that floods are not unknown events for Central European rivers. In a way, this last one resembles the floods of 2006 and 2013 that hit in Elbe and Danube basins . Usually, events of such an intensity hit with a recurrence interval of 500 – 1000 years. However, the estimation of the recurrence interval lies in an analysis of historical records. Global warming is altering local weather conditions leading to a higher number of extreme events worldwide .
Summer 2021 floods seem to be a direct consequence of the extreme heatwaves that hit the Pacific Northwest and Northern Europe in June and early July 2021. The higher the temperature of the atmosphere, the higher the amount of absorbed water vapor, and hence, the higher the precipitation rate .
Additionally, global warming may also be affecting the northern hemisphere jet stream, leading to more frequent successions of long-time droughts and heavy rainfalls . Although the correlation between global warming and the jet stream seems reasonable given the recent weather anomalies, it remains unproved.
Unproved does not mean inexistent. The remarks of Prof. Carl-Friedrich Schleussner, Head of the Climate Science at Climate Analytics and researcher at the Humboldt-Universität Berlin, on the summer 2021 floods perfectly explain why studying unassessed global warming effects is key nowadays :