July heatwaves ‘would have been almost impossible without climate change’
They are now expected to occur every few years and will become hotter and more frequent as long as people keep burning fossil fuels, scientists said.
This month’s heatwaves in southern Europe and North America would have been almost impossible without human-induced climate change, which also made the heatwave in China 50 times more likely, scientists have said.
After the hottest June on record for the Earth, temperatures soared in south-western US states and Mexico, with reports of people dying in Phoenix after suffering burns from super-heated pavements and roads.
Across the Mediterranean, heatwaves unofficially named after hellish Greek mythological figures pushed temperatures way beyond 40C and led to wildfires forcing the evacuation of thousands of people in Greece.
World Weather Attribution, a group of scientists from the UK and the Netherlands, said the heatwaves will get hotter and happen more frequently until the world stops burning fossil fuels.
Their rapid study found that without human-induced climate change, China’s heat would have been a one-in-250-year event, while the heatwaves in the US/Mexico region and southern Europe would have been statistically almost impossible.
Similar to previous studies, they said, the heatwaves were 2.5C warmer in southern Europe, 2C warmer in North America and 2C warmer in China compared with what they would have been if people had not warmed the atmosphere by emitting greenhouse gases.
If the global average temperature rises to 2C above pre-industrial levels – the less ambitious goal of the Paris Agreement – heatwaves will occur every two to five years, the scientists said.
Dr Friederike Otto of the Grantham Institute for Climate Change and the Environment, Imperial College London, said: “The result of this attribution study is not surprising.
“The world hasn’t stopped burning fossil fuels, the climate continues to warm and heatwaves continue to become more extreme. It is that simple.
“If we do not, tens of thousands of people will keep dying from heat-related causes each year.”
Europe in particular is heating faster than the global average because it sits between the increasingly hotter Arctic and Saharan regions.
Last summer, it is estimated that more than 61,000 people died because of heat across the continent.
There have been reports of hundreds of deaths in this year’s extreme heat but the true extent will not be known for some time as many places do not keep detailed heat-death records and statisticians need time to calculate the number of excess deaths.
The World Weather Attribution scientists warned of an “urgent need” for heat action plans, especially in cities, as temperatures often rise several degrees above the surrounding area in what is known as the urban heat island effect.
Sjoukje Philip, of the Royal Netherlands Meteorological Institute, said: “The planet isn’t warming evenly.
“Climate scientists are working to understand the complex relationships between increasing global and regional average temperatures.
“Once again, our study shows the significant impact of the rapid rate of warming on local temperatures in Europe.
“It underscores the urgent necessity for Europe to continuously take adaptation and mitigation measures.”
