The World Weather Attribution consortium, which includes scientists from Imperial College London and the Red Cross Red Crescent Climate Centre, used peer-reviewed methods to compare this week’s heat wave to other hot European summers in 1976 and 2003.
“Over the full extent of this heat wave, we found that in the last 50 years … the chance of a heat wave like this has changed immensely,” said lead author Theodore Keeping, an extreme weather researcher at Imperial College London.
“This event would not have been possible in June without climate change,” he added. “The three-day [average] nighttime temperatures would not have been possible at any time of year without climate change, and the chance of the three-day maximum daily temperatures like this occurring at any time of the year has increased by over 500 times” since 1976.
By 1976, the planet had heated by just 0.3 C above preindustrial levels, rising to 0.6 C in 2003 and 1.4 C last year. There is scientific consensus that heat waves are becoming more frequent and hotter with every fraction of a degree.
For the large Western and Central European region analyzed — which ranges from northern Spain and the U.K. into southern Sweden and eastern Poland — “this heatwave is the most severe ever recorded,” the scientists wrote.
The scientists also say that the daytime temperatures seen this week are now 10 times more likely to occur than during the brutal 2003 summer, when 70,000 people died from heat-related causes. This week’s high nighttime temperatures are even around 100 times more likely than they were 23 years ago.