The release of methane and carbon dioxide from the permafrost thaw will accelerate global warming and add up to $ 70tn (£ 54tn) at the expense of global climate, according to the most advanced study yet of the economic implications of Arctic melting.
If countries do not improve on their commitments to the Paris Agreement, this feedback mechanism, combined with the loss of white heat-deflecting ice, will lead to a nearly 5 percent increase in global warming and associated costs, an article published Tuesday in Nature Communications said.
According to the researchers, their study is the first to calculate the economic impact of reduced permafrost and albedo – a measure of how light hits the reflected surface without being absorbed – based on the most advanced computer models of what is expected to happen to the Arctic as temperatures rise. It shows how much challenged natural systems will exacerbate the problem caused by human emissions, making it harder and more costly to solve.
They evaluated shares of CO2 And methane trapped within a permafrost using samples taken from a depth of three meters at a number of points around the pole. These were run using the most advanced climate simulation software in the US and in the Met Office in the UK to predict how much gas will be released at various levels of warming.Even with supercomputers, the number of crunching took weeks because the vast geography and complex climate interactions of the Arctic vomit into multiple variables. The researchers then applied models of previous economic impact to assess possible costs.
Permafrost melt is the main concern. Greenhouse gases, which have been frozen underground for centuries, have already begun to escape at the current level of 1 ° C of global heating. So far the effect is small. Ten Gigatons of CO2 Were released from ice but this source of emissions will increase rapidly after temperatures rise beyond 1.5C.
On the current runway of at least 3C warming by the end of the century, melting permafrost is expected to discharge 280 gigatonnes of carbon dioxide and 3 gigatonnes of methane, which has a climate effect that is 10 to 20 times stronger than CO2.
This will increase the global cost of destruction, adaptation and emissions reduction of $ 70tn between now and 2300. This is 10 times higher than the expected benefits of Arctic melting, such as easier navigation for ships and mineral access, the newspaper says.
It will also add to global inequality, because most of the economic burden – equal to almost all of the current gross domestic product – may be borne by countries in poorer regions, such as India and Africa, which are most vulnerable to rising temperatures.
"It's discouraging that we have it ahead of us," said Dmitry Yumashev of Lancaster University. "Even at 1.5C to 2C, there are effects and costs, but they are lower so we can limit it, we have technology and processes, but we do not move fast enough."
The new predictions contained some good news, because the effect of the permafrost virus was in the low range of what he feared. Previous estimates suggested these Arctic tipping points could add more than 10% to climate costs. Some feared that the methane alone could prove catastrophic, but the new data showed that CO2 Remains the biggest concern.
"We still have a time bomb, but it's not as big as previously believed," Yumashev said. But he warned against complacency because even at the low end the damages are enormous, the research has a great deal of uncertainty and the costs of some other potential tipping points have not yet been calculated.