Summer Arctic ice melt carries monstrous $60 trillion price tag

A melt pond in the Arctic ice. (Stefan Hendricks, Alfred Wegener Institute.)

A group of European scientists has shed more light on the issue of melting Arctic sea ice in the journal Nature this week, revealing a surprisingly-overlooked aspect of climate change that could end up costing the nations of the world $60 trillion — a daunting number, considering that the entire world economy in 2012 added up to about $70 trillion.

When we've discussed climate change in the Arctic as it relates to the economy in the past, the picture has generally been pretty positive. Ocean shipping routes previously rendered inaccessible most of the year and tricky for the short summer months will be open to more vessels. Fishing ranges will be similarly exposed. Also, and probably the most seductive to many players in the global economy, there's oil under all that ice, and natural gas, too. It's estimated that 13% of the undiscovered oil in the world lies within the Arctic Circle, along with 30% of undiscovered natural gas. Insurance giant Lloyd's of London estimates investment in the Arctic will grow to be worth $100 billion over the next decade.

[ Related: Melting permafrost found in Antarctica's dry valleys ]

All of this does, indeed, sound pretty good. Now for the catch.

With the Arctic, as with all things in life, you can't get something for nothing. According to the authors of the Nature article, Gail Whiteman, Chris Hope and Peter Wadhams, the bill for access to Arctic goodies is not only steep, but those left holding it are likely to be the ones least able to shoulder the load.

The price, in this case, is that the frozen Arctic is home to sequestered methane. A lot of it.

Methane is the second most important greenhouse gas, behind 'crowd-favorite' carbon dioxide. It's actually lucky for us that we've dumped more CO2 into the atmosphere than we have methane, because methane is a much stronger radiative forcing agent — that is, every pound of methane in the atmosphere is the equivalent of 21 pounds of carbon dioxide. It's also explosive, and it can displace oxygen in confined areas, making oxygen-poor areas that a person can suffocate in. So, it's probably for the best we don't put too much in the air... but let's just stick to the climate change part for now.

Most of the methane we've put into the atmosphere thus far comes from industries like (surprise) petroleum processing, landfills, and of course, 'cow farts'. The one portion of the Arctic subject to permafrost that the group considered — the East Siberian Arctic Shelf — houses a 50-gigaton reservoir of methane, just waiting to be released when summer ice melt is sufficient enough to let methane outgas from waters and seabeds that haven't previously been able to warm up during the summer.

That's 50-gigatons, in just one region. The really disturbing part is there's no way to tell whether this will be emitted in a slow-but-steady way over 50 years, or all at once —what many are calling a 'huge methane belch'. Actually, maybe the really disturbing part is that the authors of the Nature article state: "The total cost of Arctic change will be much higher."

So, they've hypothetically added the 50-gt of methane to the atmosphere. How does that work out to costing the world $60 trillion dollars? To figure out the economic impacts of this potentially rapid change, the researchers used a computer model that "calculates the impacts of climate change and the costs of mitigation and adaptation measures" — in other words, how things change and what it costs us to deal with them.

The average of the many model runs shows how the release of the sequestered methane boosts the rate of warming, jumping previous estimates of future temperature forward by 15 to 35 years. Citing the Stern Review, a 2006 document produced for the British government, the authors report "about 80% of [the consequences] 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."

Since the fates of developing regions of the world don't typically seem to trouble the economic powerhouses who stand to benefit from the explotation of the positive effects of melting the Arctic, there's more food for thought. The authors also pointed out flooding of coastal cities, like New York, and the potential change to the jet stream across North America and Europe. Weather enthusiasts are no doubt familiar with the jet stream as our main weather-driver, and how messing with it can lead to things like this past spring's cold spell in Europe, or the flooding in Alberta a month ago, or the sweltering heat wave we had in northeastern North America just last week.

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Of course, we can't know the all the effects until they're upon us. This study only modeled the result of defrosting one region of the Arctic, for instance. It's a big problem to wrap your head around. Even the authors of the article say "it will be difficult — perhaps impossible — to avoid [these] large methane releases", and estimates of the cost of adapting to climate change already run about $400 trillion. Another $60 trillion almost sounds like a drop in an already-overwhelming bucket, but studies like this, however bleak they sound, are important nonetheless.

The only thing worse than facing this kind of a problem is ignoring it.

(Images courtesy: Getty, NSIDC/NASA, Whiteman/Hope/Wadhams)

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