Danger from the deep: New climate threat as methane rises from cracks in Arctic ice

Scientists shocked to find greenhouse gas 70 times more potent than CO2 bubbling from deep ocean

A new source of methane – a greenhouse gas many times more powerful than carbon dioxide – has been identified by scientists flying over areas in the Arctic where the sea ice has melted.

Click here to see 'The deadly depths - Methane release in the Arctic' graphic

The researchers found significant amounts of methane being released from the ocean into the atmosphere through cracks in the melting sea ice. They said the quantities could be large enough to affect the global climate. Previous observations have pointed to large methane plumes being released from the seabed in the relatively shallow sea off the northern coast of Siberia but the latest findings were made far away from land in the deep, open ocean where the surface is usually capped by ice.

Eric Kort of Nasa's Jet Propulsion Laboratory in Pasadena, California, said that he and his colleagues were surprised to see methane levels rise so dramatically each time their research aircraft flew over cracks in the sea ice.

"When we flew over completely solid sea ice, we didn't see anything in terms of methane. But when we flew over areas were the sea ice had melted, or where there were cracks in the ice, we saw the methane levels increase," Dr Kort said. "We were surprised to see these enhanced methane levels at these high latitudes. Our observations really point to the ocean surface as the source, which was not what we had expected," he said.

"Other scientists had seen high concentrations of methane in the sea surface but nobody had expected to see it being released into the atmosphere in this way," he added.

Methane is about 70 times more potent as a greenhouse gas than carbon dioxide when it comes to trapping heat. However, because methane is broken down more quickly in the atmosphere, scientists calculate that it is 20 times more powerful over a 100-year cycle. The latest methane measurements were made from the American HIPPO research programme where a research aircraft loaded with scientific instruments flies for long distances at varying altitudes, measuring and recording gas levels at different heights.

The study, published in the journal Nature Geoscience, covered several flights into the Arctic at different times of the year. They covered an area about 950 miles north of the coast of Alaska and about 350 miles south of the North Pole. Dr Kort said that the levels of methane coming off this region were about the same as the quantities measured by other scientists monitoring methane levels above the shallow sea of the East Siberian Arctic Shelf.

"We suggest that the surface waters of the Arctic Ocean represent a potentially important source of methane, which could prove sensitive to changes in sea ice cover," the researchers write. "The association with sea ice makes this methane source likely to be sensitive to changing Arctic ice cover and dynamics, providing an unrecognised feedback process in the global atmosphere-climate system," they say.

Climate scientists are concerned that rising temperatures in the Arctic could trigger climate-feedbacks, where melting ice results in the release of methane which in turn results in a further increase in temperatures.

"We should be concerned because there's so many things in the Arctic where the warming feeds further warming. There are many things in the Arctic that do respond to warming," said Euan Nisbet, a methane expert at Royal Holloway University of London.

Start your day with The Independent, sign up for daily news emails
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
SPONSORED FEATURES
Independent Dating
and  

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

iJobs Job Widget
iJobs General

Recruitment Genius: Head Chef

£22000 - £25000 per annum: Recruitment Genius: This Garden Centre complex base...

Recruitment Genius: Buyer

£36000 - £38000 per annum: Recruitment Genius: A Buyer is required to join thi...

SThree: Trainee Recruitment Consultant

£20000 - £25000 per annum + OTE £45K: SThree: SThree Group have been well esta...

SThree: Trainee Recruitment Consultant

£20000 - £25000 per annum + OTE £45000: SThree: SThree Group have been well es...

Day In a Page

Turkey-Kurdish conflict: Obama's deal with Ankara is a betrayal of Syrian Kurds and may not even weaken Isis

US betrayal of old ally brings limited reward

Since the accord, the Turks have only waged war on Kurds while no US bomber has used Incirlik airbase, says Patrick Cockburn
VIPs gather for opening of second Suez Canal - but doubts linger over security

'A gift from Egypt to the rest of the world'

VIPs gather for opening of second Suez Canal - but is it really needed?
Jeremy Corbyn dresses abysmally. That's a great thing because it's genuine

Jeremy Corbyn dresses abysmally. That's a great thing because it's genuine

Fashion editor, Alexander Fury, applauds a man who clearly has more important things on his mind
The male menopause and intimations of mortality

Aches, pains and an inkling of mortality

So the male menopause is real, they say, but what would the Victorians, 'old' at 30, think of that, asks DJ Taylor
Man Booker Prize 2015: Anna Smaill - How can I possibly be on the list with these writers I have idolised?

'How can I possibly be on the list with these writers I have idolised?'

Man Booker Prize nominee Anna Smaill on the rise of Kiwi lit
Bettany Hughes interview: The historian on how Socrates would have solved Greece's problems

Bettany Hughes interview

The historian on how Socrates would have solved Greece's problems
Art of the state: Pyongyang propaganda posters to be exhibited in China

Art of the state

Pyongyang propaganda posters to be exhibited in China
Mildreds and Vanilla Black have given vegetarian food a makeover in new cookbooks

Vegetarian food gets a makeover

Long-time vegetarian Holly Williams tries to recreate some of the inventive recipes in Mildreds and Vanilla Black's new cookbooks
The haunting of Shirley Jackson: Was the gothic author's life really as bleak as her fiction?

The haunting of Shirley Jackson

Was the gothic author's life really as bleak as her fiction?
Bill Granger recipes: Heading off on holiday? Try out our chef's seaside-inspired dishes...

Bill Granger's seaside-inspired recipes

These dishes are so easy to make, our chef is almost embarrassed to call them recipes
Ashes 2015: Tourists are limp, leaderless and distinctly UnAustralian

Tourists are limp, leaderless and distinctly UnAustralian

A woefully out-of-form Michael Clarke embodies his team's fragile Ashes campaign, says Michael Calvin
Blairites be warned, this could be the moment Labour turns into Syriza

Andrew Grice: Inside Westminster

Blairites be warned, this could be the moment Labour turns into Syriza
HMS Victory: The mystery of Britain's worst naval disaster is finally solved - 271 years later

The mystery of Britain's worst naval disaster is finally solved - 271 years later

Exclusive: David Keys reveals the research that finally explains why HMS Victory went down with the loss of 1,100 lives
Survivors of the Nagasaki atomic bomb attack: Japan must not abandon its post-war pacifism

'I saw people so injured you couldn't tell if they were dead or alive'

Nagasaki survivors on why Japan must not abandon its post-war pacifism
Jon Stewart: The voice of Democrats who felt Obama had failed to deliver on his 'Yes We Can' slogan, and the voter he tried hardest to keep onside

The voter Obama tried hardest to keep onside

Outgoing The Daily Show host, Jon Stewart, became the voice of Democrats who felt the President had failed to deliver on his ‘Yes We Can’ slogan. Tim Walker charts the ups and downs of their 10-year relationship on screen