Warm spring worsened Europe’s extreme 2018 summer drought, study says


Europe’s extreme 2018 summer drought was worsened by an unusually warm and sunny spring in the same year, a new study finds.

Sunny weather in the months preceding the heatwave caused plant growth to accelerate across the continent, which, in turn, led to the fast drying out of soil, the research says.

The dry soil, in combination with record-breaking summer heat, created the conditions for 2018’s extreme drought – which caused millions of pounds of crop damage and fanned wildfires from Greece to the UK.

The findings come as the UK emerges from its sunniest spring on record. This year’s unprecedented sunshine could heighten the risk of another extreme drought in summer, depending on weather conditions in the coming months, the lead author tells Carbon Brief.

Parched

The northern hemisphere’s 2018 summer heatwave dominated frontpages . The extreme heat lasted for months and temperature records were broken simultaneously across North America, Europe and Asia.

At the same time, Europe was plunged into a continent-wide drought , which caused severe crop damage and fanned the flames of wildfires.

A study covered by Carbon Brief found that the summer heat seen across the northern hemisphere in 2018 would have not been possible in a world without human-caused climate change.

The new study, published in Science Advances , is the first to investigate how weather in the months leading up to the heatwave could have contributed to Europe’s extreme drought.

It finds unusually sunny and warm weather in the spring had a lasting “legacy effect” on the land, which then amplified drought conditions in the summer, says Dr Ana Bastos , a group leader at the Max Planck Institute for Biogeochemistry in Germany and lead author of the study. She tells Carbon Brief:

“Spring conditions led to an enhancement of photosynthesis early on in the growing season, but at the cost of strong soil-water depletion. In the crop-dominated areas in central Europe, increased growth in spring made ecosystems more vulnerable to drought in summer.”

Premature plants

For the study, the authors reexamined the weather conditions in Europe in both the spring and summer of 2018. They also looked into weather conditions during two previous European summer heatwaves in 2003 and 2010 .

The maps below show mean temperature (top), rainfall (middle) and solar radiation (bottom) across Europe during the spring months of 2003 (left), 2010 (middle) and 2018 (right). On the maps, red signifies above average temperatures or rainfall deficits, while yellow shows above average solar radiation (sunny weather).

Mean temperature (top), rainfall (middle) and solar radiation (bottom) across Europe during the spring months of 2003 (left), 2010 (middle) and 2018 (right). Red signifies above average temperatures or rainfall deficits, while yellow...

Top