Man-made climate change has made this summer’s northern hemisphere drought at least 20 times more likely, according to a rapid analysis released Wednesday, which warns such extreme droughts are becoming more common with global warming.

The three months from June to August were the hottest in Europe on record, and the exceptionally high temperatures resulted in the worst drought the continent has experienced since medieval times.

Harvest withered in Europe’s breadbaskets as the historic drought resulted in record wildfire intensity and severely strained the continent’s power grid.

Consecutive heatwaves between June and July, which saw temperatures in the UK climb above 40 degrees Celsius (104 degrees Fahrenheit) for the first time, resulted in more than 24,000 deaths in Europe.

China and North America also experienced unusually high temperatures and exceptionally low rainfall during this period.

An international team of climate scientists has found that warming caused by human activities makes such extreme weather events significantly more likely than they were at the beginning of the industrial age.

The World Weather Attribution Service calculated that agricultural and environmental droughts were at least 20 times more likely over the northern hemisphere thanks to global warming.

“The summer of 2022 has shown how human-caused climate change increases the risks of agricultural and ecological droughts in densely populated and cultivated regions of the northern hemisphere,” says Sonia Seneviratne, Professor at the Institute for Atmosphere and Climate at ETH Zurich in Switzerland and one of the study authors.

To quantify the impact of human-caused climate change on soil moisture, the team analyzed weather data and computer simulations to compare the real climate as it is today – that is, about 1.2 °C hotter than pre-industrial – with a climate without man-made warming.

They found that western and central Europe were hit by particularly severe droughts and significantly reduced crop yields.

Moisture in the top 7 cm of soil in the northern hemisphere led to a five times greater likelihood of severe climate change-related droughts, according to the study.

For the top three feet of soil — known as the root zone — drought has become at least 20 times more likely this summer due to global warming.

“What’s really most relevant to agriculture and environmental impact is the top meter of soil, because that’s where plants have their roots,” Seneviratne said.

Overall, a Northern Hemisphere drought like this summer is likely to occur every 20 years in today’s climate, compared to once every 400 years in the mid-1800s.

Producers in Europe and China have warned of much lower-than-expected harvests of staple crops due to the drought after food prices rose to multi-year highs following the Russian invasion of Ukraine in February.

Friederike Otto, lecturer in climate sciences at Imperial College London, called the crop failure “particularly worrying”.

“It followed a climate change-induced heatwave in South Asia that also devastated crops, and came at a time when global food prices were already extremely high due to the war in Ukraine,” she said.

Otto said the northern hemisphere generally shows a “clean signal of climate change” in its overall warming trends.

Maarten van Aalst, director of the Red Cross Red Crescent Climate Center and professor of climate and disaster resilience at the University of Twente, said governments need to do much more to prepare for future heat and drought shocks, which will become more frequent as temperatures rise .

“We’re talking about tens of thousands of people who have been killed by these phenomena and one thing we’re seeing is the impacts compounding and cascading across regions and sectors,” he said.

“It’s happening before our eyes even faster than we might have expected.”