Heatwaves fuelled by climate change, say experts
Rising global temperatures caused by human activity are making the heatwaves gripping the northern hemisphere more likely, scientists warn.
Extreme heat has been seen in the northern hemisphere, with temperatures exceeding 30C (86F) in the Arctic circle, Japan declaring a “natural disaster” due to searing temperatures and heatwaves in parts of North America and Siberia.
Professor Peter Stott, Met Office science fellow in attribution, likened the increased chances of a heatwave to roll-
ing a dice and getting a six – but that climate change was weighting the dice.
He said: “What we’ve seen this summer is repeated throws throwing up a six in different parts of the world. If you get a six over and over again you start to think, ‘This is not normal, somebody has given me a loaded dice’.”
He said the chances of the 2003 heatwave in Europe happening again was more than doubled by climate change, and predictions by climate models that heatwaves would increase in frequency “are coming true before our eyes”.
He said the “jury is out” on the extent to which climate change is affecting the jet stream, whose current pattern is keeping an area of high pressure to the west of Britain and causing the hot, dry weather.
But he said: “It’s settled into a pattern here this summer, and what that means when it’s in this pattern, the Arctic temperatures are very much warmer, and temperatures are globally very much warmer, it’s fuelling these heatwaves.”
Temperatures have risen globally around 1C above preindustrial levels, as a result of greenhouse gases put into the atmosphere from activities such as burning fossil fuels, while increases in the Arctic have been much greater.
Figures from Nasa show last month was tied as the third warmest June in 138 years of record-keeping at 0.77C above the 1951-1980 average.