This should be headline news. It should be plastered all over the front pages of newspapers and web sites around the world. TV pundits should be demanding action from the politicians who have put action on emissions reductions in the “too hard” basket. The evidence is beginning to suggest that Wally Broecker’s angry beast, fed up with being prodded with ever bigger sticks, is going to bite back hard — and bite back soon. Is there time to stop all this happening? Perhaps — but it will take a huge effort, a wartime response when the world is being led by billionaires, ideologues and their appeasers intent on denying reality. We’re sleepwalking to disaster. By the time we wake up, it will be too late.

Arctic sea ice time bomb ticking:
the bang’s gonna be hugeReading this press release about a new paper in Palaeogeography, Palaeoclimatology, Palaeoecology spoiled my day. It might not be obvious to a casual reader just glancing through the morning news — but a couple of paragraphs leapt out at me:

Atmospheric carbon dioxide concentrations recently reached 400 parts per million for the first time since the Pliocene Epoch, three million years ago. During this era, Arctic surface temperatures were 15-20 degrees Celsius warmer than today’s surface temperatures.

Ballantyne’s findings suggest that much of the surface warming likely was due to ice-free conditions in the Arctic. That finding matches estimates of land temperatures in the Arctic during the same time. This suggests that atmospheric carbon dioxide concentrations of 400 ppm may be sufficient to greatly reduce the spatial extent and seasonal persistence of Arctic sea ice.

In other words, losing Arctic sea ice brings huge warming to the lands around the Arctic Ocean. This is extremely bad news for a number of reasons:

• We’re losing the Arctic sea ice well ahead of any schedule derived from model predictions. The sea ice summer minimum could drop below 1 million km2 within a decade. I have argued that it might be even sooner…
• Arctic warming and sea ice losses are already impacting northern hemisphere weather patterns.
• Once the summer sea ice has gone, it’s only a question of how long it will take for the winter ice to disappear. When I last looked at this issue, three years ago, I suggested this might happen much sooner than anyone expected — perhaps by the 2040s.
• When I wrote that post, I suggested that — if we were unlucky — winter ice loss could be within the current climate commitment — that is, within the warming we would expect to see from current levels of greenhouse gases. Ballantyne et al’s new paper explicitly supports that view.
• The consequences of warming of 10ºC to 20ºC on the lands around the Arctic Ocean are horrendous. Recent research suggests that total warming of as little as 1.5ºC could be enough to start major releases of methane as permafrost in Alaska, Canada and Siberia melts. There are also huge deposits of methane beneath the East Siberian Shelf (ESS) that are already beginning to discharge to the atmosphere as their permafrost cap begins to disintegrate under a warming ocean.
• A persistent large scale release of methane would transform the global climate system and make efforts to contain warming by reducing anthropogenic emissions more or less futile. We would be heading far beyond 2ºC deep into the realms of catastrophe.
• Just to complete my bad day, this Guardian report on a new paper modelling the economic costs of a 50 Gt methane release from the ESS suggests that the impact would generate an “extra $60 trillion (net present value) of mean climate change impacts” — comparable to total global GDP at present. World economy over, in other words.

Arctic Warming Could Cost Upwards of $60 Trillion The worldwide impacts of a rapidly warming Arctic could cost the global economy an estimated $60 trillion, nearly equal to the entire global economy in 2012, according to a new study. That report, published Wednesday in the journal Nature, is the first to analyze the potential economic costs of rapid Arctic warming.

The study bluntly warns that the tendency for policymakers to focus solely on the benefits of an increasingly open Arctic Ocean — like increased mining, oil and gas drilling, and maritime shipping — misses the longer-term “economic time bomb.” The Arctic region, the study said, is “pivotal” to the functioning of the global climate system, and disrupting it will not come cheaply.

The Coast Guard ice breaker Healy clearing the path for another ship.
Credit: U.S. Coast Guard.

“Estimates are that the economic benefits of Arctic shipping and oil exploration will be four orders of magnitude less than the additional costs analysed here,” co-author Peter Wadhams, a professor of ocean physics at the University of Cambridge, told Climate Central.

The Arctic has been warming twice as fast as lower latitudes, and the region plays a key role in regulating the Earth’s climate system, since the bright white land and sea ice reflects an enormous amount of incoming solar energy back to space, and the Arctic Ocean helps drive global ocean currents. As sea ice and land ice melt, they expose darker surfaces below, and those surfaces absorb more solar energy, leading to warming. This process, through which Arctic warming feeds upon itself and accelerates, is known as Arctic amplification.

Last year saw the most extensive loss of Arctic sea ice ever recorded in the 34-year satellite history. When the melt season finally ended in late September, the Arctic Ocean managed to hold onto less than half of the average sea ice extent seen during the 1979-to-2000 period. So far this summer, sea ice has remained above the level of the 2012 record melt, but not by much. The past six years have had the six smallest sea ice extents since 1979, and sea ice volume has also declined precipitously.

The new study focuses on one potential impact of Arctic warming in particular — the release of methane gas, which is a potent global warming agent, from frozen deposits known as “ methane hydrates,” located beneath the East Siberian Sea. Studies have projected that as the ocean temperatures warm in response to the loss of sea ice, some of the methane will be released into the atmosphere. Methane is a more potent, but shorter-acting, global warming gas when compared to carbon dioxide (CO2).

For the Nature study, researchers calculated the average global economic consequences of the release of 50 gigatonnes of methane over the course of one decade — from 2015 to 2025 — from thawing undersea permafrost. They found that the costs would vary between $10 trillion to $220 trillion, depending on the emissions reductions that are put in place during the same period for other greenhouse gases, such as CO2.

The mean estimate of $60 trillion is close to the estimated value of the entire global economy in 2012, which was $70 trillion, the study said.