PARIS - Blistering heat that has baked swathes of North America and Europe this month would have been "virtually impossible" without human-caused climate change, researchers said on Tuesday, as intense temperatures spark health alerts and stoke ferocious wildfires.
Intense temperatures have swept much of the southwest and southern United States including in Phoenix, Arizona, which suffered a record-breaking three straight weeks of highs above 43C. To trace how far the July heatwaves in the northern hemisphere had departed from what would have been expected without that warming, Otto and her WWA colleagues used weather data and computer model simulations to compare the climate as it is today with that of the past.Otto said in the past it would have been "basically impossible" that such severe heat waves would happen at the same time and that people should no longer be surprised to see temperature records tumbling.
The study also found that these heatwaves were hotter than they would have been without climate change.