Why you should care about permafrost

2013-03-06 10:36

Andreas Späth

Transcript of a very brief conversation with my wife:
Me: “Is it nerdy to be obsessed with permafrost?”
Her: “Perma who?”
Me (in my head): “Somewhat nerdy then, hey?!”

But why should my wife (and you) know what permafrost is and care about its status? Well, it turns out that even though as Africans, few of us have had the opportunity to encounter permafrost in person, its future could have very significant effects on our lives and those of our offspring.

Permafrost is ground that is permanently frozen, often to depths of many metres (formally it’s defined as subsurface material that remains below 0oC for at least two consecutive years). It covers nearly a quarter of the northern hemisphere’s continental area, particularly in the arctic regions of Russia, Canada and Alaska, where an active surface layer, around two metres in thickness, thaws and refreezes in summer/winter cycles, but the soil underneath stays frozen continuously.

Crucially, permafrost contains large quantities of frozen organic matter and thus acts as a massive store of carbon; carbon that is prevented from entering the atmosphere, where it would contribute to global warming.

In effect, permafrost is the planet’s deep freezer where carbon is kept on ice and most of it has been there since the last ice age.

The problem: anthropogenic climate change is causing the equivalent of a power failure: the freezer is starting to defrost - the permafrost is starting to melt. And you know what happens when your freezer at home has been off for a while. Expect lots of funky gaseous emissions as microbes start going to town on its contents.

In the case of permafrost, the thawing organic matter embedded in it is digested by a variety of bacteria, some of which produce CO2 while others emit methane, a greenhouse gas (GHG) that’s about 25 times more powerful at trapping heat in the atmosphere than CO2 over a 100 year period.

On top of that, thawing permafrost also releases large quantities of nitrous oxide, which is 310 times more effective than CO2 (but is ranked third in importance behind CO2 and methane because it occurs in smaller amounts globally).

Permafrost is estimated to contain a staggering 1.7 trillion tons of carbon - twice the amount currently in the atmosphere. A 2012 report from the United Nations Environment Programme points out that GHGs thawing out of permafrost may ultimately constitute as much as 39% of global emissions. It also notes that scientists calculating future global temperature increases have not taken into account methane contributions from permafrost until now.

Current research suggests that permafrost is melting faster than previously thought. New records from stalagmites and stalactites in a Siberian cave suggest that the region’s continuous permafrost would start melting on a large scale if the global average temperature rose to 1.5oC above pre-industrial levels.

Sobering thoughts, considering that we’re already around 0.6 to 0.7oC above pre-industrial levels and that most countries have only committed themselves to keep global warming to within 2oC with ever-decreasing odds of actually achieving that target.

Some scientists have tried to downplay the situation, but only because permafrost is expected to melt relatively slowly, over two or three centuries, and because humans are likely to emit much greater quantities of GHGs over the same period.

Whichever way you slice it, melting permafrost is not a good thing. It’s a self-reinforcing, snowballing process that will gather speed and volume gradually (as temperatures rise, more permafrost will melt, leading to still higher temperatures and so on), and it will have knock on effects on other natural processes.

It’s also a clear warning signal that things are dangerously out of kilter and that the complex planetary equilibrium which makes life as we know it possible is teetering on the edge. We may be living through the moment in history - right now - when we tip over the first domino that will set of an irreversible and unstoppable chain reaction.

Which, in a nutshell, is why my wife (and you) should be worried about arctic tundra thousands of kilometres away turning into mud.

- Andreas freelance writer with a PhD in geochemistry. Follow him on Twitter: @Andreas_Spath

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