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.