Researchers said they believe that human-driven climate change probably intensified the recent European heat wave and increased the number of heat-related deaths.

Scientists at Imperial and the London School of Hygiene and Tropical Medicine used peer-reviewed techniques to calculate that about 2,300 people in 12 cities likely died from the heat in last week’s bout of high temperatures, with nearly two-thirds of them dying because of the extra degrees that climate change added to the natural summer warmth.

Europe's latest spell of sizzling heat, which ended last week, caused a threefold rise in heat-related deaths because human-induced climate change boosted the intensity of the heat wave, British scientists said.