Extreme droughts in central Europe likely to increase sevenfold.

Researchers say moderate reductions in CO2 emissions could halve their likelihood.

Extreme droughts are likely to become much more frequent across centralEurope, and if global greenhouse gas emissions rise strongly they could happen seven times more often, new research has shown.

The area of crops likely to be affected by drought is also set to increase, and under sharply rising CO2 levels would nearly double in central Europe in the second half of this century, to more than 40m hectares (154,440 sq miles) of farmland.

Central Europe suffered its biggest and most damaging drought on record in 2018 and 2019, which had two of the three warmest summer periods ever recorded on the continent. The summers were also much drier than average, and more than half of the region suffered severe drought conditions.

Rivers and watercourses dried up, some crops were ruined and wildfires increased during these two years of extreme drought. The only other drought on record to come close, in 1949 and 1950, affected a land area about a third smaller.

By comparing the conditions with weather records dating back to 1766, and using computer models of climate change, researchers from UFZ-Helmholtz Centre for Environmental Research in Leipzig, Germany, were able to forecast that moderate reductions in greenhouse gases from their current levels would halve the likelihood of such extreme droughts, and shrink the affected land area by nearly 40%.

Rohini Kumar, one of the authors of the study, told the Guardian the findings were concerning. “The findings indicate that introducing measures to reduce future carbon emissions may lower the risk of more frequent consecutive drought events across Europe. On the one hand, we need to step up our efforts to reduce greenhouse gases worldwide, and at the same time deal with strategies to adapt to climate change.”

Strong reductions in greenhouse gases would reduce the frequency of such extreme droughts to “a very negligible number”, said Kumar.

The paper is published on Thursday in the journal Scientific Reports.

The study adds to an increasing body of research showing the impacts of global heating on Europe. Previous studies have suggested that southern and central Europe will experience more drought, with one study projecting that European cities will become much hotter, with London forecast to have a climate more like Barcelona by 2050 and southern and central European cities seeing more extreme levels of heat.

Constantin Zohner, of the Crowther Lab at the Swiss Federal Institute of Technology in Zurich, who was not involved in the research, said the study showed the consequences of failing to curb greenhouse gas emissions.

“[These] findings are an important warning to the world that continued emissions will strongly exacerbate future drought events, threatening ecosystems, agriculture and human wellbeing,” he told the Guardian. “The study, once more, highlights the urgent need for climate action in order to maintain the functionality of ecosystems and ensure water supply to future generations.”

6 August 2020

The Guardian