Why is Europe Going through a Heatwave?

The Guardian 

Why is it so hot?

Partly, it's just the luck of the weather. The jet stream - the west-to-east winds that play a big role in determining Europe's weather - has been further north than usual for about two months. A stationary high-pressure weather system has left the UK and much of continental Europe sweltering. Iceland, by contrast, has been hit with clouds and storms that would normally come further south.

The jet stream's northerly position may have been influenced by temperatures in the north of the Atlantic, which have been relatively warm in the subtropics and colder south of Greenland.

"The current hot and dry spell in the UK is partly due a combination of North Atlantic ocean temperatures, climate change and the weather," said Len Shaffrey, a professor of climate science at the University of Reading.

The influence of climate change on the jet stream is still being explored.

Is climate change to blame?

The heatwaves in the northern hemisphere are undoubtedly linked to global warming, scientists say. "There's no question human influence on climate is playing a huge role in this heatwave," said Prof Myles Allen, a climate scientist at the University of Oxford.

On Thursday the university will publish an analysis of how much more likely climate change made Europe's current heatwave. Similar heatwaves have happened in the past when the planet was cooler - the world was two-thirds of a degree celsius cooler in 1976, a notably hot year in the UK. But climate change made them happen more often, Allen said.

Prof Peter Stott, a science fellow at the Met Office, said global warming of 1C since the industrial revolution was clearly making extreme heat more likely. "It is...