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 (Thursday in Manila).
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 tons, or gigatons (Gt), of methane escaped over a decade from the floor of the East Siberian Sea, covering two million square kilometers (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—the 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 United Nati’s 2C warming target.
In an e-mail exchange with Agence France-Presse, Hope said that if the 50Gt were released over 20 years, from 2015-2035, the cost would be around $64.5 trillion.