Millions of people across Europe endured what scientists described as the most severe June heatwave ever recorded across the region, with new research concluding that the extreme temperatures would have been virtually impossible without human-caused climate change.
The World Weather Attribution (WWA) group said the heatwave sweeping France, Italy, Spain, the United Kingdom and other parts of Europe marked an unprecedented event for the month, with temperatures exceeding 40 degrees Celsius in many areas.
The heatwave has strained medical services, disrupted transport, affected businesses and was moving eastward toward Germany and central Europe after causing dozens of deaths in western parts of the continent.
According to the WWA analysis, a comparable heatwave occurring under the climate conditions of June 1976 would have been about 3.5 degrees Celsius cooler, while a similar event in 2003 would have been roughly 2 degrees cooler.
Researchers found that extreme June heatwaves have become tens to hundreds of times more likely since 2003 and were "virtually impossible" 50 years ago.
Nearly 45 percent of the approximately 850 European cities examined had broken or were expected to break their all-time June heat stress records, with humidity further increasing health risks by reducing the body's ability to cool itself.
The report identified the current event as the second significant European heatwave this year, following unusually early high temperatures recorded across central and western Europe in May.
Scientists said the atmospheric weather pattern behind the heatwave was not unusual, but that climate change had significantly intensified the temperatures.
The WWA concluded that fossil fuel-driven global warming was the primary factor behind the severity of the event, while natural weather variability alone could not explain the extreme conditions.
Researchers warned that continued warming would make similar events increasingly common and more intense unless greenhouse gas emissions are reduced.
The report said a rapid phase-out of fossil fuels is critical to limiting future temperature increases and reducing the growing risks posed by extreme heat across Europe.