Europe’s ‘end of the century’ extreme heat and drought could occur much sooner than previously thought

Simultaneous episodes of extreme heat and drought, typical of a moderate warming scenario predicted for the end of the 21st century, could occur earlier and repeatedly in Europe, reports a study published in Earth and Environment Communications.

The study suggests there is more than a 10% chance that two successive years of extreme end-of-the-century heat will occur between 2050 and 2075, while five-year European megadroughts could also occur.

Climate change is leading to more frequent simultaneous extreme weather and climate events, such as droughts, heatwaves, floods or fires, which can cause serious socio-economic damage. Additionally, it is not clear to what extent increased variability in the North Atlantic system might affect these extreme events in Europe.

Laura Suarez-Gutierrez and her colleagues studied how quickly end-of-the-century heat stress and drought could occur in Europe – and the role that North Atlantic variability could play over decades – in a scenario moderate climate leading to warming of around 2.25° Celsius by the end of the century. The authors used a range of simple and compound extreme heat stress and drought measurements, as well as an ensemble of 100 simulations from the Max Planck Institute’s Grand Ensemble climate model.

The authors found that the probability of single or compound episodes of extreme heat stress and end-of-century drought occurring repeatedly year after year is greater than one in ten by 2050-2074. All forms of heat stress (when the air is warm and humid during the day or hot at night) could already reach a probability of 1 in 10 by 2030-2039.

Additionally, above-average sea surface temperatures in the North Atlantic will contribute to dry and warm conditions in Europe. The authors calculate that end-of-century temperatures will be twice as likely in the decades from 2030 under these conditions.

The authors conclude that North Atlantic climate variability could increase the frequency of multi-year periods of extreme heat and drought in Europe and that preparation for such devastating events needs to be strengthened.