2022 droughts ‘virtually impossible without climate change’, study finds

Human-driven climate change made the droughts that gripped large swaths of Europe, China and North America this year at least 20 times more likely, an international group of scientists has concluded.

Unusually high temperatures in the northern hemisphere dried out soils during the summer months and fuelled droughts that destroyed crops, forced factories to close and hit hydropower generation, the World Weather Attribution group found. The group draws together scientists from different global institutions to produce peer-reviewed weather studies.

Climate change made the agricultural and ecological droughts that hit the northern hemisphere “at least 20 times more likely”, said the scientists, who analysed soil moisture levels between June and August across the region, excluding the tropics.

A summer as hot as this year’s would have been “virtually impossible without climate change,” they found.

“With further global warming we can expect stronger and more frequent summer droughts in the future,” said Dominik Schumacher, a co-author from the Institute for Atmospheric and Climate Science in Switzerland.

A severe heatwave this summer fuelled wildfires across Europe and sent temperatures to a record high of more than 40C in England. Unusually hot and dry conditions also pushed down the levels of rivers in Europe and China, which hit trade and power production.

Crops suffered from the heat and the lack of water and the combined impacts of the droughts added to the rising cost of essentials such as food and energy.

“Over the summer, fires in Europe were the worst on record, China issued its first national drought alert and more than half of the US was in drought,” said the researchers, a group of 21 scientists from institutions in countries including Switzerland, France, the UK and the US. 

The impact of a particularly severe drought that gripped western and central Europe was made worse by poor water infrastructure and high rates of water leakage from pipes, the researchers found.

According to the study — which looked at moisture levels for the top 7cm and the top 100cm of soil — a drought of the kind recorded this year “can be expected around once in 20 years” in today’s climate, in both the northern hemisphere and the smaller central European region.

In the absence of human caused climate change, the drought witnessed in the northern hemisphere would have been expected to occur around once every 400 years or less, while the drought in the European region would have occurred roughly once every 60-80 years, the scientists found.

Rising temperatures were the main cause of the increased risk of drought, with changes in rainfall less important, they added. The likelihood and intensity of extreme weather events including droughts are likely to increase with further warming, scientists have warned.

“Heat and drought in Europe this summer not only caused tens of thousands of direct deaths, but also aggravated the cost of living crisis, compounding the impacts of the Ukraine war,” said Maarten van Aalst, director of the Red Cross Red Crescent Climate Centre.

“We are witnessing the fingerprint of climate change not just in specific hazards, but also in the cascading of impacts across sectors and regions,” he said.

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