Recent extreme heatwaves 'a result of global warming'

Severe summer heat caused by humans not natural events, says Nasa scientist

A A A

Global warming is responsible for the recent spate of summer heatwaves, according to James Hansen, the scientist who first alerted the world to the dangers of climate change. Dr Hansen, director of Nasa's Goddard Institute for Space Studies in New York, said that the "climate dice" are now loaded in favour of extreme heatwaves which now affect 10 per cent of the Earth's surface, compared with about 1 per cent in the period between 1951 to 1980.

Dr Hansen said that at least three extreme summers over the past decade, the 2003 heatwave in Europe which killed more than 50,000 people, the 2010 hot summer in Moscow and last year's droughts in Texas and Oklahoma, were almost certainly the result of man-made climate change rather than natural events.

In a study published in the Proceedings of the National Academy of Sciences, Dr Hansen and his colleagues said that rising global temperatures caused by increases in concentrations of carbon dioxide have significantly increased the probability of such extreme heatwaves.

"This is not a climate model or a prediction but actual observations of weather events and temperatures that have happened," Dr Hansen says in an accompanying article in The Washington Post.

"Our analysis shows that it is no longer enough to say that global warming will increase the likelihood of extreme weather and to repeat the caveat that no individual weather event can be directly linked to climate change," he said. "To the contrary, our analysis shows that, for the extreme hot weather of the recent past, there is virtually no explanation other than climate change."

Dr Hansen was the first scientist to warn the wider world of the dangers of global warming when in 1988 he gave evidence to the US Senate that the burning of fossil fuels was raising global average temperatures.

Since then, most scientists have been cautious about attributing any single weather extreme to climate change but in recent years a number of researchers have pointed out that some extreme weather events, such as the 2003 heatwave in Europe, fell outside what would be expected of natural climate variability.

Dr Hansen said that his study shows that the climate dice have been loaded in such a way as to make unusual hot events more extreme and more frequent.

"Such events used to be exceedingly rare. Extremely hot temperatures covered about 0.1 per cent to 0.2 per cent of the globe in the base period of our study, from 1951 to 1980," Dr Hansen said. "In the last three decades, while the average temperature has slowly risen, the extremes have soared and now cover about 10 per cent of the globe," he said.

PROMOTED VIDEO
Have you tried new the Independent Digital Edition apps?
Life and Style
A still from a scene cut from The Interview showing North Korean leader Kim Jong-un's death.
tech
Voices
'That's the legal bit done. Now on to the ceremony!'
voicesThe fight for marriage equality isn't over yet, says Siobhan Fenton
Life and Style
Approaching sale shopping in a smart way means that you’ll get the most out of your money
life + styleSales shopping tips and tricks from the experts
Arts and Entertainment
Bianca Miller and Katie Bulmer-Cooke are scrutinised by Lord Sugar's aide Nick Hewer on The Apprentice final
tvBut Bianca Miller has taken on board his comments over pricing
News
in picturesWounded and mangy husky puppy rescued from dump
News
newsAstonishing moment a kangaroo takes down a drone
Life and Style
Duchess of Cambridge standswith officials outside of the former wartime spy centre in Bletchley Park
tech
News
people
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
iJobs Job Widget
iJobs General

Ashdown Group: IT Support Technician - 12 Month Fixed Term - Shrewsbury

£17000 - £20000 per annum: Ashdown Group: IT Helpdesk Support Technician - 12 ...

The Jenrick Group: Maintenance Planner

£28000 - £32000 per annum + pension + holidays: The Jenrick Group: Maintenance...

The Jenrick Group: World Wide PLC Service Engineer

£30000 - £38000 per annum + pesion + holidays: The Jenrick Group: World Wide S...

The Jenrick Group: Project Manager

£35000 per annum + Pension+Bupa: The Jenrick Group: We are recruiting for an e...

Day In a Page

Surrounded by high-rise flats is a little house filled with Lebanon’s history - clocks, rifles, frogmen’s uniforms and colonial helmets

Clocks, rifles, swords, frogmen’s uniforms

Surrounded by high-rise flats is a little house filled with Lebanon’s history
Return to Gaza: Four months on, the wounds left by Israel's bombardment have not yet healed

Four months after the bombardment, Gaza’s wounds are yet to heal

Kim Sengupta is reunited with a man whose plight mirrors the suffering of the Palestinian people
Gastric surgery: Is it really the answer to the UK's obesity epidemic?

Is gastric surgery really the answer to the UK's obesity epidemic?

Critics argue that it’s crazy to operate on healthy people just to stop them eating
Homeless Veterans appeal: Christmas charity auction Part 2 - now LIVE

Homeless Veterans appeal: Christmas charity auction

Bid on original art, or trips of a lifetime to Africa or the 'Corrie' set, and help Homeless Veterans
Pantomime rings the changes to welcome autistic theatre-goers

Autism-friendly theatre

Pantomime leads the pack in quest to welcome all
The week Hollywood got scared and had to grow up a bit

The week Hollywood got scared and had to grow up a bit

Sony suffered a chorus of disapproval after it withdrew 'The Interview', but it's not too late for it to take a stand, says Joan Smith
From Widow Twankey to Mother Goose, how do the men who play panto dames get themselves ready for the performance of a lifetime?

Panto dames: before and after

From Widow Twankey to Mother Goose, how do the men who play panto dames get themselves ready for the performance of a lifetime?
Thirties murder mystery novel is surprise runaway Christmas hit

Thirties murder mystery novel is surprise runaway Christmas hit

Booksellers say readers are turning away from dark modern thrillers and back to the golden age of crime writing
Anne-Marie Huby: 'Charities deserve the best,' says founder of JustGiving

Anne-Marie Huby: 'Charities deserve the best'

Ten million of us have used the JustGiving website to donate to good causes. Its co-founder says that being dynamic is as important as being kind
The botanist who hunts for giant trees at Kew Gardens

The man who hunts giants

A Kew Gardens botanist has found 25 new large tree species - and he's sure there are more out there
The 12 ways of Christmas: Spare a thought for those who will be working to keep others safe during the festive season

The 12 ways of Christmas

We speak to a dozen people who will be working to keep others safe, happy and healthy over the holidays
Birdwatching men have a lot in common with their feathered friends, new study shows

The male exhibits strange behaviour

A new study shows that birdwatching men have a lot in common with their feathered friends...
Diaries of Evelyn Waugh, Virginia Woolf and Noël Coward reveal how they coped with the December blues

Famous diaries: Christmas week in history

Noël Coward parties into the night, Alan Clark bemoans the cost of servants, Evelyn Waugh ponders his drinking…
From noble to narky, the fall of the open letter

From noble to narky, the fall of the open letter

The great tradition of St Paul and Zola reached its nadir with a hungry worker's rant to Russell Brand, says DJ Taylor
A Christmas ghost story by Alison Moore: A prodigal daughter has a breakthrough

A Christmas ghost story by Alison Moore

The story was published earlier this month in 'Poor Souls' Light: Seven Curious Tales'