LONDON (Thomson Reuters Foundation) - Methane emissions from melting permafrost beneath the East Siberian Arctic Shelf could drive rapid climate change that would cause damage close to the $70 trillion value of the 2012 world economy, researchers say.
According to a study released Wednesday, the release of trapped methane from permafrost in just one Arctic ice shelf could have a global impact of $60 trillion – and the costs would disproportionately affect developing countries over the coming century.
The study highlights an urgent need for global action to curb climate change, researchers said.
This study is the first to look at a specific physical feature – the East Siberian Arctic Shelf – in order to model the potential economic effects of methane emissions in the Arctic. The shelf has for the past four years been the subject of field research that shows it is at ever-increasing risk of releasing an estimated 50 gigatonnes of methane into the atmosphere.
Methane is about 25 times more potent a greenhouse gas than carbon dioxide, and so large-scale releases of it threaten to dramatically increase the speed and severity of global warming.
“We’ve seen a big increase in the amount of methane observed to be released each year,” said Peter Wadhams of the University of Cambridge, one of the study’s authors. “So the observations are beginning to confirm the prediction that this seabed permafrost is melting and perhaps a large amount of methane will be released.”
What is less certain is exactly how much will be released, and when. The researchers explored potential costs associated with a decade-long “pulse” of 50 gigatonnes of methane, as well as slower and more rapid releases. The estimated cost of $60 trillion is the mean of those calculated possibilities.
“We don’t want this methane to burst or even slowly be released – we don’t want it to be released at all,” said Gail Whiteman of Erasmus University Rotterdam, one of the authors of the study. “But if (the world) keeps warming, it will be released. It’s just a matter of time.”
If the underwater permafrost beneath East Siberian Arctic Shelf melted enough to release such significant amounts of methane into the atmosphere, it could bring forward by 15 to 35 years the average date at which Earth would experience a 2 degree Celsius increase in temperature. That would amplify climate events like flooding, droughts and storms – not to mention broader impacts of a warming Arctic, such as rising sea levels and ocean acidification.
Discussions on climate change in the Arctic have so far largely focused on the economic gains that could accompany melting in the region. New stores of undiscovered gas and oil could generate billions of dollars, for example, and melting ice could open up shipping lanes through the Arctic. A study last year from Lloyd’s and Chatham House thinktank estimated that investment in the Arctic could reach $100 billion within 10 years.
But the new study argues that damage done by methane emissions would dwarf those gains, even in favorable scenarios. At minimum, expected permafrost melt and methane releases would cost at least $10 trillion, Whiteman said. “No matter what, the costs are likely to be very large,” she said.
And developing countries – particularly those in Africa, Asia and South America – would likely bear around 80 percent of those costs as they are expected to be more significantly impacted by resulting extreme weather. While countries like Canada and the United States might have a greater interest in the Arctic because they could gain from melting sea ice in the short-term, Whiteman said, it’s crucial for a broad range of countries – particularly developing nations – to join the conversation.
Wadhams pointed out that the release of 50 gigatonnes of methane would add about an additional 15 percent to the current estimated costs of climate change, estimated at $450 trillion. The researchers stressed that dealing with carbon dioxide emissions – which are driving the majority of current climate change – must become a global priority.
“We’ve really got to cut down on CO2 emissions,” Whiteman said. “The idea that we don’t necessarily have to do that is ludicrous. We need emissions cut by 2020 if not earlier, by 5 percent per year.”
The study also emphasized an urgent need to rethink the future of the Arctic. Whiteman hopes the knowledge of this methane risk will bring pause in the debate of whether or not to exploit oil and gas reserves in the region.
“The Arctic is so important for the global climate system,” she said. “As soon as it starts to change, we can start anticipating large impacts around the world. It should be much more important to the global community.”
Erin Berger is a Thomson Reuters Foundation intern, writing on climate change issues.
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