Arctic methane leakage an `economic time bomb`
Paris: Massive leakage of methane from thawing shoreline in the Arctic would devastate the world`s climate and economy, a trio of scientists warned on Wednesday.
Billions of tonnes of this potent greenhouse gas are locked in the shallow frozen shelf of the Arctic Ocean, which warms when summer sea ice retreats as a result of the greenhouse-gas effect, they said in a contribution to Nature.
The team modelled what would happen if 50 billion tonnes, or gigatonnes (Gt), of methane escaped over a decade from the floor of the East Siberian Sea, covering two million square kilometres (772,200 square miles) of the Arctic Ocean off northeastern Russia.
"The methane release would bring forward the date at which the global mean temperature rise exceeds two degrees Celsius (3.6 degrees Fahrenheit) by between 15 and 35 years," said Chris Hope of Cambridge Judge Business School, part of England`s University of Cambridge.
Gail Whiteman, a professor of sustainability, management and climate change at Erasmus University in Rotterdam, the Netherlands, described the threat as an "invisible time bomb".
"The mean impacts of just this one effect, $60 trillion, approaches the $70 trillion value of the world economy in 2012."
The high cost is explained by damage to the climate system, reflected in worse floods, droughts, storms and heat stress, she said.
Eighty percent of the effects would occur in poorer economies in Africa, Asia and South America, according to their model, called PAGE09.
The estimates are based on how the added methane would affect two trends -- one for existing greenhouse-gas emissions, which are very high, and the other for lower emissions giving a more than one-in-two chance of meeting the UN`s 2C warming target.
In an email exchange with AFP, Hope said that if the 50 Gt were released over 20 years, from 2015-2035, the cost would be around $64.5 trillion.
If the release were spread over 30 years, from 2015-2045, it would be $66.2 trillion.
"This is because more of the methane remains in the atmosphere in the period when impacts are expected to be higher in the latter half of this century," he said.
If 25 Gt were released, the cost in all scenarios would be roughly halved.
Scientists have long worried about methane locked up in shoreline sediments and also in permafrost on land.
Methane is 25 times more effective than carbon dioxide (CO2) in trapping solar heat.
The big concern is that the methane, if released to the atmosphere, adds to global warming, which thus accelerates the thaw, adding more gas and amplifying the temperature rise -- a "positive feedback," or vicious circle in climate terms.
But evidence for such a threat is sketchy, research into it is meagre and the conclusions often contested. Some experts also say there could be as-yet unknown mechanisms in permafrost thaw that may limit the methane leakage.
In 2008, Russian scientists writing in the journal Geophysical Research said they estimated 540 Gt of methane to be stored in the Siberian Arctic shelf. Of this, up to 50 Gt could be considered as being "highly possible for abrupt release at any time".
In 2010, another Russian team, reporting in Science, said they had found large amounts of leakage from perforated permafrost on the shelf.
In contrast, in 2011, another team, also Russian, said they saw evidence of outgassing in the East Siberian Sea. But they attributed this to a long-delayed consequence of the end of the last Ice Age, not from recent changes in the Arctic Ocean.
More from India
More from World
More from Sports
More from Entertaiment
- UP: Jammu-bound Muri Express derails in Kaushambi
- Five unmanned parachute-like objects spotted over Mumbai airport
- CBSE Board Class 12th Exam Results 2015 declared
- Jaipur girl Mini Rajpal wins Miss India Deaf 2015!
- Delhi's 2015 CBSE Class 12 topper M Gayatri talks to Zee Media
- Dawood's intercepted phone calls prove yet again he is in Pakistan
- Mumbai architecture creates double decker bus from scrap!
- No respite from heat for next three days: IMD
- One year of Modi govt: PM addresses mega rally in Mathura
- Watch: Mumbai cops find new secret agents in housewives!
- DNA: Sikh man in New Zealand removed his turban to help injured kid
- Police registers case after parachute-like objects were spotted over Mumbai airport
- One year of Modi govt: PM promises to fulfil aspirations
- Growing medical negligence in Delhi's AIIMS
- DNA: AIIMS doctor removes both kidneys of minor, claims she had only one
- Heatwave claims over 550 lives so far, Delhi saw hottest day
- Cbse.nic.in & cbseresults.nic.in Class 12th XII Results 2015: CBSE Board Class 12th XII Exam Results 2015 declared
- LIVE - Cbse.nic.in & cbseresults.nic.in Class 12th XII Results 2015: CBSE Board Class 12th XII Exam Results 2015 to be announced shortly
- Check cbseresults.nic.in for CBSE Class 12 result 2015
- Check WBBSE (wbresults.nic.in) Class 12th Results: West Bengal Board (wbscvet.org) Higher Secondary Class XII Vocational Results to be declared today at 4 PM
- Two dead, over 100 injured as Muri Express derails in UP; Prabhu announces Rs 2 lakhs ex-gratia for kin of dead
- PM Narendra Modi's Mathura rally: As it happened
- CBSE Class 12 results out: Here's how you can check
- Public rally on 100 days of AAP govt: As it happened
- Arvind Kejriwal's Aam Aadmi Party changes its logo
- One year of NDA govt: PM Modi writes open letter to nation, promises to transform India
- Unidentified flying objects spotted over Mumbai airport not motorised: Home Department
- World optimistic about India: PM Narendra Modi on 1 year of NDA govt
- Militants kill five, target telecoms in Kashmir attacks
- Bharatiya Janata Party lacks majority for Ram Temple, Article 370: Amit Shah