The loss of sea ice and land snow could tip the planet into a new and unprecedented cycle of climatic change and add yet another $70 trillion (£54 tn) to the estimated economic cost of global warming.
In yet another somber statement of the challenge presented by climate change, driven by ever-increasing emissions of greenhouse gases from the fossil fuels that power the global economy, British, European, and US researchers took a look at two manifestations of warming.
One is the growing levels of ancient carbon now being released into the atmosphere as the Arctic permafrost begins to melt. The other is the reduced reflection of solar radiation back into space as what had once been an expanse of snow and ice melts, to expose ever greater areas of light-absorbing blue sea, dark rock and scrubby tundra.
Abrupt surprises
The concern is with what the scientists like to call “non-linear transitions”. The fear is not that global warming will simply get more pronounced as more snow and ice disappears. The fear is that at some point the melting will reach a threshold that could tip the planet into a new climate regime that would be irreversible, and for which there has been no parallel in human history.
And if so, the costs in terms of climate disruption, heat waves, rising sea levels, harvest failures, more violent storms, and more devastating floods and so on could start to soar.
The scientists report in the journal Nature Communications that if the nations of the world were to keep a promise made in Paris in 2015 to contain planetary warming to “well below” 2°C above the average for most of human history by the year 2100, the extra cost of Arctic ice loss would still tip $24 tn.
But on the evidence of national plans tabled so far, the world seems on course to hit 3°C by the century’s end, and the extra cost to the global economies is estimated at almost $70 tn.
Read more at Fast Arctic Melt Could Cost $70 Trillion
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