By Bill McGuire
There was actually some good news on the climate breakdown front last week, but don’t break out the champagne just yet. A new study, published in Nature Communications revealed that Arctic melting, as a result of accelerating global heating, will add around US$70 trillion – about five percent – to the climate breakdown bill. And why is this good news? I hear you ask. Well, apparently, the figure was expected to be higher – at around twice this. Of course, this is not good news at all. Just another piece of a jigsaw that, when completed, will disclose a picture of a planet trashed beyond redemption and a civilisation on its knees.
The new study makes a fist of estimating the cost of the global consequences of changes that occur across the Arctic region, even supposing that nations stick to their Paris Climate Agreement pledges, and it makes for depressing reading. The bill is the equivalent of almost a year’s global GDP, but the economic burden will not be borne by all countries equally. The poorer nations – especially across Africa and in South Asia – will take a far greater hit, driving increasing hardship and raising global inequality.
Harsh though they are, be in no doubt that the research findings massively underestimate the true cost of the impact of global heating at high northern latitudes. This is because the study only takes account of two factors: (1) the release of greenhouses gases as a consequence of thawing land permafrost, and (2) the absorption of more of the sun’s heat as white ice is replaced by dark land and sea. It does not consider a clutch of other critical feedback mechanisms, each of which presents a colossal threat in its own right; notably the release of methane due to thawing submarine permafrost, modifications to the Gulf Stream and associated currents caused by the melting of the Greenland Ice Sheet, and changes in the ability of the great Boreal forests of Canada and Eurasia to continue to suck up carbon.
Furthermore, I suspect that even the authors of the new study, would agree that the final figure would need to be taken with a very large pinch of salt. As far as I am concerned, at least, lumping together models of climate feedback mechanisms that are poorly constrained with economic models that often bear little relationship to the real world (how many predicted the 2008 crash?), results in numbers worth about as much as ones picked randomly out of a hat.
In all honesty, the only thing the study actually tells us is that the impact of global heating on the Arctic will be catastrophic and extremely costly – but we know that already. Arriving at a figure that seeks to monetise a small part of the threat is meaningless and does nothing to help anyone. So, take the results on board, always bearing in mind that the true picture is far worse. Draw strength from this and keep the pressure on the decision makers to take action to tackle the climate emergency. Not next year, or a decade down the line, but now – today!
Bill McGuire is Professor Emeritus of Geophysical & Climate Hazards at UCL and author of Waking the Giant: How a Changing Climate Triggers Earthquakes, Tsunamis and Volcanic Eruptions. He was a contributor to the IPCC 2012 report on Climate Change & Extreme Events and Disasters.