Methane gas is one of the wildest of wild cards in the game of trying to assess future climate change. But among the many uncertainties, scientists know two things: there is a vast amount of methane in the Arctic, and if a substantial portion of it were to be released into the atmosphere, it could change the global climate.
The latest study is only the first, tentative stab at trying to assess the economic impacts of a sudden methane release.
Unlike most peer-reviewed research papers in Nature, this one was clearly published under the rubric of “comment”.
The researchers have broken new ground by tackling the difficult issue of assessing the economic costs of a large-scale escape of methane, which as a greenhouse gas is 20 times more potent than carbon dioxide over 100 years.
Using an economic computer model, they estimated it would cost $60 trillion (R587 trillion) if just one of the known Arctic methane reserves were to be suddenly released through the melting of the permafrost.
Some will argue that these kinds of computer models are not to be trusted, and there are many assumptions and uncertainties in this kind of work. But the researchers believe this is a useful exercise in balance given the optimism over the supposed economic benefits of Arctic oil and gas exploration - to say nothing of the shipping bonanza offered by an ice-free Northern Sea Route.
There are large uncertainties. There is a 5 percent chance that the costs could be as little as $10 trillion and a 5 percent chance of there being $220 trillion.