As the extreme temperatures sweep across countries in the world claiming the lives of people and damaging property, scientists Tuesday said July’s heatwaves were caused by human activities — the driving force behind climate change.

In July, hot weather was on record in several countries including China, India, the US, Canada, and Southern European, with some of them witnessing deadly wildfires spreading across thousands of acres and burning record areas of land.

Several people were also hospitalised due to heatstroke conditions.

Over the weekend, thousands of tourists were evacuated from the Greek island of Rhodes to escape wildfires caused by a record-breaking heatwave.

“Without human-induced climate change, the events this month would have been extremely rare,” according to a study by World Weather Attribution, a global team of scientists that researches climate change and its effects on extreme weather.

“European and North American temperatures would have been virtually impossible without the effects of climate change,” said Izidine Pinto of the Royal Netherlands Meteorological Institute, one of the study’s authors.

“In China, it was around 50 times more likely to happen compared to the past.”

The World Weather Attribution team estimated that rising greenhouse gas concentrations made the European heatwave 2.5 Celsius (4.5 Fahrenheit) hotter than it would otherwise have been. They also drove up the North American heatwave by 2C and the one in China by 1C.

Scientists said: “As well as directly impacting human health, the heat has caused large-scale crop damage and livestock losses with US corn and soybean crops, Mexican cattle, southern European olives as well as Chinese cotton all severely affected.”

They further noted: “El Nino probably contributed to the additional heat in some regions, but rising greenhouse gases were the major factor and heatwaves will become increasingly likely if emissions are not slashed.”

According to their estimation, prolonged periods of extreme heat were likely to hit every two to five years if average global temperatures rise 2C above pre-industrial levels.

Average temperatures are currently estimated to have risen more than 1.1C.

“The events we have looked at are not rare in today’s climate,” said Friederike Otto, a scientist with the Grantham Institute for Climate Change in London, told journalists.

“It’s not surprising from a climatological point of view, that these events are happening at the same time.”

“As long as we keep burning fossil fuels we will see more and more of these extremes,” she said. 

“I don’t think there’s any stronger evidence that any science has ever presented for a scientific question.”