Is a $60 trillion "time bomb" about to explode in the Arctic? It depends on which scientists you believe.
A controversial paper in the journal Nature recently argued that warming temperatures could release 50 billion tons of methane currently frozen in the Arctic seabed and drastically accelerate climate change. Because methane is a potent greenhouse gas, such a huge release could speed up sea ice retreat, increase the amount of solar energy that the ocean absorbs, and exacerbate the ongoing melt. It could also mean global temperatures rising more quickly, moving the world's climate past generally-agreed-upon "tipping point" limits.
The paper uses the same methodology as the Stern Review, a landmark study from 2006. In Nature, Gail Whiteman, Peter Wadhams, and Chris Hope estimate a price tag on the potential damage in their commentary:
The release of methane from thawing permafrost beneath the East Siberian Sea, off northern Russia, alone comes with an average global price tag of $60 trillion in the absence of mitigating action--a figure comparable to the size of the world economy in 2012 (about $70 trillion). The total cost of Arctic change will be much higher.
Using various scenarios, they say the methane could take from 10 to 50 years to emerge. But they're clear about who'll be hit hardest:
The economic consequences will be distributed around the globe, but the modeling shows that about 80% of them will occur in the poorer economies of Africa, Asia and South America. The extra methane magnifies flooding of low-lying areas, extreme heat stress, droughts and storms.
Other scientists have disputed the assumptions, however, as Carbon Brief and The Guardian have both noted. They say the methane is unlikely to escape to the atmosphere that quickly and that some of it could be broken down in the ocean. Andrew Revkin, at the New York Times, has a good roundup of the "glaring problems" others had with the Nature paper here.
But Institute for Policy Research and Development director Nafeez Ahmed, in The Guardian, says these skeptics rely on outdated models. The reality on the ground, as captured by scientists with the International Arctic Research Center, is that temperatures are rising faster than elsewhere and that current ice melt is consistent with the methane effect, he says. "The authors who so confidently dismiss the idea of extensive methane release are simply not aware of the new mechanism that is causing it," Ahmed quotes Nature co-author Wadhams, a professor of ocean physics at Cambridge University.
Whoever you believe, there's no disagreement about the "feedback effects" of climate change or that methane releases from the Arctic are harmful. Even if the methane emerges slowly, it would still be catastrophic: The research shows the same effect if methane releases over the course of 50 years as it does over 10 years. As the authors say:
In all of these cases there is a steep global price tag attached to physical changes in the Arctic, notwithstanding the short-term economic gains for Arctic nations and some industries.
[Image: Iceberg via Shutterstock]