Melting permafrost a carbon risk
The Arctic is one of the most vulnerable parts of the world when it comes to climate change, and has the potential to contribute some costly climate-related effects, such as sea-level rise from melting glaciers.
But one of the biggest emerging talking points in conversations about climate change in the Arctic involves something else – permafrost. This frozen soil typically contains large amounts of carboncontaining organic matter.
That’s fine as long as the soil stays frozen – but as the Arctic continues to heat up year after year, more permafrost is starting to thaw, unleashing its stored car- bon into the atmosphere in the process in the form of both methane and carbon dioxide, mostly the latter.
Altogether, scientists estimate Arctic permafrost could contain 1700 gigatonnes (equal to 1.7 trillion tonnes) of carbon.
The release of some of this carbon, even gradually, could have dramatic consequences for the climate, leading to an acceleration in global climate change, more warming in the Arctic, and more thawing, which would consequently cause more carbon to be released in a kind of vicious cycle.
But what haven’t been closely examined, until now, are the econ- omic consequences of this thawing permafrost. As it turns out, they could be very large.
Chris Hope, an expert in policy modelling at the University of Cambridge, and Kevin Schaefer, a research scientist at the National Snow and Ice Data Centre, have concluded that carbon emissions from thawing permafrost could cost the world trillions of dollars over the next 200 years.
In a study published this week in the journal Nature Climate Change, the researchers used two models – one that estimates emissions from thawing permafrost and one that calculates the resulting temperature increases and glo- bal climate-related impacts – to evaluate the global economic impact of permafrost emissions up through the year 2200. They suggest carbon emissions from thawing permafrost could cause climate effects which will cost the world about $43 trillion over the next 200 years. That would increase the total economic impact of climate change – currently estimated to come to about $326 trillion – by 13 per cent.
‘‘There is almost nothing in the literature on this,’’ said Hope. ‘‘We are the first to combine a physical model and an integrated assessment model in this way.’’