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
ebooks
ebooksAn introduction to the ground rules of British democracy
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: Telesales Executive - OTE £25,000

£13000 - £25000 per annum: Recruitment Genius: Would you like to be part of a ...

Recruitment Genius: 1st Line Technical Support Engineer

£19000 - £23000 per annum: Recruitment Genius: This IT and Telecoms company ar...

Recruitment Genius: Assistant Manager - Visitor Fundraising

£23000 per annum: Recruitment Genius: The Visitor Fundraising Team is responsi...

Recruitment Genius: Developer

£30000 - £35000 per annum: Recruitment Genius: This is an opportunity to join ...

Day In a Page

The Silk Roads that trace civilisation: Long before the West rose to power, Asian pathways were connecting peoples and places

The Silk Roads that trace civilisation

Long before the West rose to power, Asian pathways were connecting peoples and places
House of Lords: Outcry as donors, fixers and MPs caught up in expenses scandal are ennobled

The honours that shame Britain

Outcry as donors, fixers and MPs caught up in expenses scandal are ennobled
When it comes to street harassment, we need to talk about race

'When it comes to street harassment, we need to talk about race'

Why are black men living the stereotypes and why are we letting them get away with it?
International Tap Festival: Forget Fred Astaire and Ginger Rogers - this dancing is improvised, spontaneous and rhythmic

International Tap Festival comes to the UK

Forget Fred Astaire and Ginger Rogers - this dancing is improvised, spontaneous and rhythmic
War with Isis: Is Turkey's buffer zone in Syria a matter of self-defence – or just anti-Kurd?

Turkey's buffer zone in Syria: self-defence – or just anti-Kurd?

Ankara accused of exacerbating racial division by allowing Turkmen minority to cross the border
Doris Lessing: Acclaimed novelist was kept under MI5 observation for 18 years, newly released papers show

'A subversive brothel keeper and Communist'

Acclaimed novelist Doris Lessing was kept under MI5 observation for 18 years, newly released papers show
Big Blue Live: BBC's Springwatch offshoot swaps back gardens for California's Monterey Bay

BBC heads to the Californian coast

The Big Blue Live crew is preparing for the first of three episodes on Sunday night, filming from boats, planes and an aquarium studio
Austin Bidwell: The Victorian fraudster who shook the Bank of England with the most daring forgery the world had known

Victorian fraudster who shook the Bank of England

Conman Austin Bidwell. was a heartless cad who carried out the most daring forgery the world had known
Car hacking scandal: Security designed to stop thieves hot-wiring almost every modern motor has been cracked

Car hacking scandal

Security designed to stop thieves hot-wiring almost every modern motor has been cracked
10 best placemats

Take your seat: 10 best placemats

Protect your table and dine in style with a bold new accessory
Ashes 2015: Alastair Cook not the only one to be caught in The Oval mindwarp

Cook not the only one to be caught in The Oval mindwarp

Aussie skipper Michael Clarke was lured into believing that what we witnessed at Edgbaston and Trent Bridge would continue in London, says Kevin Garside
Can Rafael Benitez get the best out of Gareth Bale at Real Madrid?

Can Benitez get the best out of Bale?

Back at the club he watched as a boy, the pressure is on Benitez to find a winning blend from Real's multiple talents. As La Liga begins, Pete Jenson asks if it will be enough to stop Barcelona
Athletics World Championships 2015: Beijing witnesses new stage in the Jessica Ennis-Hill and Katarina Johnson-Thompson heptathlon rivalry

Beijing witnesses new stage in the Jess and Kat rivalry

The last time the two British heptathletes competed, Ennis-Hill was on the way to Olympic gold and Johnson-Thompson was just a promising teenager. But a lot has happened in the following three years
Jeremy Corbyn: Joining a shrewd operator desperate for power as he visits the North East

Jeremy Corbyn interview: A shrewd operator desperate for power

His radical anti-austerity agenda has caught the imagination of the left and politically disaffected and set a staid Labour leadership election alight
Isis executes Palmyra antiquities chief: Defender of ancient city's past was killed for protecting its future

Isis executes Palmyra antiquities chief

Robert Fisk on the defender of the ancient city's past who was killed for protecting its future