Expect more extreme winters thanks to global warming, say scientists

 

Scientists have established a link between the cold, snowy winters in Britain and melting sea ice in the Arctic and have warned that long periods of freezing weather are likely to become more frequent in years to come.

An analysis of the ice-free regions of the Arctic Ocean has found that the higher temperatures there caused by global warming, which have melted the sea ice in the summer months, have paradoxically increased the chances of colder winters in Britain and the rest of northern Europe.

Graphic: Click here to see how a warmer climate could lead to colder winters

The findings are being assessed by British climate scientists, who have been asked by ministers for advice on whether the past two cold winters are part of a wider pattern of climate change that will cause further damaging disruption to the nation's creaking transport infrastructure.

Some climate scientists believe that the dramatic retreat of the Arctic sea ice over the past 30 years has begun to change the wind patterns over much of the northern hemisphere, causing cold, Arctic air to be funnelled over Britain during winter, replacing the mild westerly airstream that normally dominates the UK's weather.

The study was carried out in 2009, before last year's harsh winter started to bite, and is all the more prescient because of its prediction that cold, snowy winters will be about three times more frequent in the coming years compared to previous decades.

The researchers used computer models to assess the impact of the disappearing Arctic sea ice, particularly in the area of the Barents and Kara seas north of Scandinavia and Russia, which have experienced unprecedented losses of sea ice during summer.

Their models found that, as the ice cap over the ocean disappeared, this allowed the heat of the relatively warm seawater to escape into the much colder atmosphere above, creating an area of high pressure surrounded by clockwise-moving winds that sweep down from the polar region over Europe and the British Isles. Vladimir Petoukhov, who carried out the study at the Potsdam Institute for Climate Impact Research in Germany, said the computer simulations showed that the disappearing sea ice is likely to have widespread and unpredictable impacts on the climate of the northern hemisphere.

One of the principal predictions of the study was that the warming of the air over the ice-free seas is likely to bring bitterly cold air to Europe during the winter months, Dr Petoukhov said. "This is not what one would expect. Whoever thinks that the shrinking of some far away sea-ice won't bother him could be wrong. There are complex interconnections in the climate system, and in the Barents-Kara Sea we might have discovered a powerful feedback mechanism," he said.

In the paper, submitted in November 2009 but published last month in the Journal of Geophysical Research, Dr Petoukhov and his colleague Vladimir Semenov write: "Our results imply that several recent severe winters do not conflict with the global warming picture but rather supplement it."

Arctic sea ice has been in retreat over recent decades, with record lows recorded in September 2007. The normal recovery of the sea ice during winter has also been affected, especially in the Barents and Kara seas which have seen significant losses of ice cover over the past decade.

Stefan Rahmstorf, professor of physics of the oceans at the Potsdam Institute, said the floating sea ice in winter insulates the relatively warm seawater from the bitterly cold temperatures of the air above it, which can be around -20C or -30C.

"The Arctic sea ice is shrinking and at the moment it is at a record low for mid-to-late December, which provides a big heat source for the atmosphere," Professor Rahmstorf said. "The open ocean actually heats the atmosphere above because the ocean in the Arctic is about 0C, and that's much warmer than the atmosphere about it. This is a massive change compared with an ice-covered ocean, where the ice operates like a lid. You don't get that heating from below.

"The model simulations show that, when you don't get ice on the Barents and Kara seas, that promotes the formation of a high-pressure system there, and, because the airflow is clockwise around the high, it brings cold, polar air right into Europe, which leads to cold conditions here while it is unusually warm elsewhere, especially in the Arctic," he explained.

The scientists emphasised that the climate is complex and there were other factors at play. It is, they said, too early to be sure if the past two cold winters are due to the ice-free Arctic.

"I want to be cautious, but basically in the past couple of months the sea ice cover has been low and so, according to the model simulations, that would encourage this kind of weather pattern," Professor Rahmstorf said.

"The last winter of 2009-10 turned out to be fitting that pattern very well, and perhaps this winter as well, so that is three data points. I would say it's not definite confirmation of the mechanism, but it certainly fits the pattern," he said.

The computer model used by the scientists also predicted that, as the ice cover continues to be lost, the weather pattern is likely to shift back into a phase of warmer-than-usual winters. Global warming will also continue to warm the Arctic air mass, Professor Rahmstorf said.

"If you look ahead 40 or 50 years, these cold winters will be getting warmer because, even though you are getting an inflow of cold polar air, that air mass is getting warmer because of the greenhouse effect," he said. "So it's a transient phenomenon. In the long run, global warming wins out."

News
people'It can last and it's terrifying'
Sport
Alexis Sanchez, Radamel Falcao, Diego Costa and Mario Balotelli
football
Sport
Danny Welbeck's Manchester United future is in doubt
footballGunners confirm signing from Manchester United
News
people Emma Watson addresses celebrity nude photo leak
PROMOTED VIDEO
Sport
footballFeaturing Bart Simpson
News
Katie Hopkins appearing on 'This Morning' after she purposefully put on 4 stone.
peopleKatie Hopkins breaks down in tears over weight gain challenge
Arts and Entertainment
Olivia Colman topped the list of the 30 most influential females in broadcasting
tv
News
Kelly Brook
peopleA spokesperson said the support group was 'extremely disappointed'
Life and Style
techIf those brochure kitchens look a little too perfect to be true, well, that’s probably because they are
Sport
Andy Murray celebrates a shot while playing Jo-Wilfried Tsonga
TennisWin sets up blockbuster US Open quarter-final against Djokovic
News
ebooksAn unforgettable anthology of contemporary reportage
Arts and Entertainment
Hare’s a riddle: Kit Williams with the treasure linked to Masquerade
booksRiddling trilogy could net you $3m
Arts and Entertainment
Alex Kapranos of Franz Ferdinand performs live
music Pro-independence show to take place four days before vote
News
news Video - hailed as 'most original' since Benedict Cumberbatch's
News
i100
Life and Style
The longer David Sedaris had his Fitbit, the further afield his walks took him through the West Sussex countryside
lifeDavid Sedaris: What I learnt from my fitness tracker about the world
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
Independent Dating
and  

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs General

Year 5 Teacher

£80 - £135 per day: Randstad Education Cheshire: Permanent post for a Key stag...

Geography Teacher

£90 - £160 per day: Randstad Education Birmingham: Geography Teacher urgently ...

SEN Teachers and Support Staff

£50 - £130 per day: Randstad Education Chelmsford: Are you an SEN Teacher or L...

SharePoint Engineer - Bishop's Stortford

£30000 - £35000 per annum + benefits: Ashdown Group: A highly successful organ...

Day In a Page

'I’ll tell you what I would not serve - lamb and potatoes': US ambassador hits out at stodgy British food served at diplomatic dinners

'I’ll tell you what I would not serve - lamb and potatoes'

US ambassador hits out at stodgy British food
Radio Times female powerlist: A 'revolution' in TV gender roles

A 'revolution' in TV gender roles

Inside the Radio Times female powerlist
Endgame: James Frey's literary treasure hunt

James Frey's literary treasure hunt

Riddling trilogy could net you $3m
Fitbit: Because the tingle feels so good

Fitbit: Because the tingle feels so good

What David Sedaris learnt about the world from his fitness tracker
Saudis risk new Muslim division with proposal to move Mohamed’s tomb

Saudis risk new Muslim division with proposal to move Mohamed’s tomb

Second-holiest site in Islam attracts millions of pilgrims each year
Alexander Fury: The designer names to look for at fashion week this season

The big names to look for this fashion week

This week, designers begin to show their spring 2015 collections in New York
Will Self: 'I like Orwell's writing as much as the next talented mediocrity'

'I like Orwell's writing as much as the next talented mediocrity'

Will Self takes aim at Orwell's rules for writing plain English
Meet Afghanistan's middle-class paint-ballers

Meet Afghanistan's middle-class paint-ballers

Toy guns proving a popular diversion in a country flooded with the real thing
Al Pacino wows Venice

Al Pacino wows Venice

Ham among the brilliance as actor premieres two films at festival
Neil Lawson Baker interview: ‘I’ve gained so much from art. It’s only right to give something back’.

Neil Lawson Baker interview

‘I’ve gained so much from art. It’s only right to give something back’.
The other Mugabe who is lining up for the Zimbabwean presidency

The other Mugabe who is lining up for the Zimbabwean presidency

Wife of President Robert Mugabe appears to have her sights set on succeeding her husband
The model of a gadget launch: Cultivate an atmosphere of mystery and excitement to sell stuff people didn't realise they needed

The model for a gadget launch

Cultivate an atmosphere of mystery and excitement to sell stuff people didn't realise they needed
Alice Roberts: She's done pretty well, for a boffin without a beard

She's done pretty well, for a boffin without a beard

Alice Roberts talks about her new book on evolution - and why her early TV work drew flak from (mostly male) colleagues
Get well soon, Joan Rivers - an inspiration, whether she likes it or not

Get well soon, Joan Rivers

She is awful. But she's also wonderful, not in spite of but because of the fact she's forever saying appalling things, argues Ellen E Jones
Doctor Who Into the Dalek review: A classic sci-fi adventure with all the spectacle of a blockbuster

A fresh take on an old foe

Doctor Who Into the Dalek more than compensated for last week's nonsensical offering