July heat waves would have been 'virtually impossible' without climate change: research

Without climate change, the heat waves impacting the U.S.-Mexico region and Southern Europe this month would have been “virtually” impossible, according to new research. 

The research, from the World Weather Attribution initiative, also found that heat impacting China would have been “about a 1 in 250 year event.”

At the start of July, heat waves hit the Southwestern U.S., as well as Mexico, Southern Europe and China. In California’s Death Valley, temperatures reached more than 125 degrees Fahrenheit, while Phoenix has seen 25 days straight with temperatures of at least 110 degrees. 

As all this occurred, the World Weather Attribution initiative also found that in all of the regions it studied, a heat wave of the same likelihood would have been “significantly cooler” without climate change.

The heat wave in Southern Europe was 2.5 degrees Celsius (4.5 degrees Fahrenheit) warmer because of climate change, it said, while the heat wave in North America was 2 degrees Celsius (3.6 degrees Fahrenheit) warmer and the heat wave in China was 1 degree Celsius (1.8 degrees Fahrenheit) degrees warmer.

The research also said that “unless the world rapidly stops burning fossil fuels,” heat events will become even more common and they will also be 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 pre industrial climate,” said the report.

In order to reach their conclusions, the scientists who prepared the report calculated the change in such an event’s probability and its change in intensity to compare the current climate to the climate of the past.