Three academics walk into a bar.
After what must have been the worst happy hour ever, they emerge having discovered that melting oceanic permafrost could come with a hefty $60 trillion dollar price tag, slightly less than the entire world economy.
We calculate that the costs of a melting Arctic will be huge, because the region is pivotal to the functioning of Earth systems such as oceans and the climate. 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.
Penned in a recent issue of Nature, Gail Whitman (Sustainability professor at Erasmus University Netherlands), Chris Hope (Policy modeler, University of Cambridge) and Peter Wadhams (Ocean physics, University of Cambridge) set out to calculate the economic consequences of an ice-free Arctic, which some have estimated could happen as early as 2020.
Their main concern followed the melting of underwater permafrost - called methane clathrates - in which natural methane gas beneath the ocean is trapped in frozen beds of ice. Normally, the cold temperatures of ocean water and high pressure of ocean sitting atop the clathrates keep them in place. But with the Arctic ice cap quickly melting, the warming may penetrate farther toward the ocean floor and release this 50 Gt reservoir of methane.
Like stinky bubbles emanating from their Arctic bathtub, methane, a much more powerful greenhouse gas than CO2 with about 20x the warming capability, could either be released gradually over time, or in one fell swoop, accelerating atmospheric warming.