Throughout July, extreme weather wreaked havoc across the planet, with record breaking temperatures in China, the United States and southern Europe, sparking wildfires, water shortages and an increase in heat-related hospitalizations.
Thousands of tourists were evacuated from the Greek island of Rhodes over the weekend to escape forest fires caused by a record heat wave.
Role climate change plays in extreme weather
According to a study by the World Weather Attribution, a global team of scientists that examines the role climate change plays in extreme weather, without human-induced climate change, this month’s events would be “extremely rare.”
“European and North American temperatures would be virtually impossible without the effects of climate change,” Izidine Pinto of the Royal Netherlands Meteorological Institute, one of the authors of the study, said during a press briefing. “It was about 50 times more likely in China than in the past.”
The World Weather Attribution team estimated that rising concentrations of greenhouse gases made Europe’s heatwave 2.5 Celsius (4.5 Fahrenheit) warmer than it would have been otherwise. They also pushed back the North American heat wave by 2°C and the one in China by 1°C.
In addition to the direct impact on human health, the heat caused widespread crop damage and livestock losses, the researchers said, with US corn and soybeans, Mexican cattle, southern European olives and also Chinese cotton badly affected.
El Nino likely contributed to additional heat in some regions, but rising greenhouse gases were the main factor, scientists said, and heat waves will become increasingly likely if emissions are not reduced.
They estimated that prolonged periods of extreme heat are likely to strike every two to five years if average global temperatures rise 2°C above pre-industrial levels. Average temperatures are currently estimated to be over 1.1°C.
“The events we looked at are not rare in today’s climate,” Friederike Otto, a scientist at the Grantham Institute for Climate Change in London, told a briefing. “From a climatological point of view, it is not surprising that these events are happening at the same time. As long as we burn fossil fuels, we’re going to see more and more of these extremes,” she said. “I don’t think there is any stronger evidence that any science has ever produced for a scientific question.”