Scientists say that the current heatwaves taking place around the world would have been “virtually impossible” without human-induced climate change
The month has seen extreme heatwaves in several parts of the Northern Hemisphere, including the Southwest of the US and Mexico, Southern Europe and China. Temperatures exceeded 50C on the 16th of July in Death Valley in the US as well as in Northwest China
Records were also reached in many other weather stations in China and the all-China heat record was broken in Sanbao on the 16th of July.
In Europe, the hottest ever day in Catalunyawas recorded and highest-ever records of daily minimum temperature were broken in other parts of Spain. In the US, parts of Nevada, Colorado and New Mexico tied their all time high, parts of Arizona, Cayman Islands, highest ever night time temperatures in Phoenix Arizona which also had its record for longest time without falling below 90F/32.2C.
Scientists from the World Weather Attribution initiative collaborated to assess to what extent human-induced climate change altered the likelihood and intensity of the extreme July heat in these three regions.
They found that without human induced climate change these heat events would however have been extremely rare.
In China it would have been about a 1 in 250 year event while maximum heat like in July 2023 would have been virtually impossible to occur in the US/Mexico region and Southern Europe if humans had not warmed the planet by burning fossil fuels.
In all the regions a heatwave of the same likelihood as the one observed today would have been significantly cooler in a world without climate change.
Similar to previous studies we found that the heatwaves defined above are 2.5°C warmer in Southern Europe, 2°C warmer in North America and about 1°C in China in today’s climate than they would have been if it was not for human-induced climate change.
They say that unless the world rapidly stops burning fossil fuels, these events will become even more common and the world will experience heatwaves that are even hotter and longer-lasting.
A heatwave like the recent ones would occur every 2-5 years in a world that is 2°C warmer than the preindustrial climate.
