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Ch. 6: Sea ice meltback begins
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Author:  Chris OConnor [ Tue Jun 16, 2020 6:39 pm ]
Post subject:  Ch. 6: Sea ice meltback begins

A Farewell to Ice: A Report from the Arctic
by Peter Wadhams


Please use this thread to discuss Ch. 6: Sea ice meltback begins.

Author:  Robert Tulip [ Sun Aug 09, 2020 6:45 am ]
Post subject:  Re: Ch. 6: Sea ice meltback begins

Chapter 6 – Sea Ice Meltback Begins
“Naturally, given his occupation, Scoresby was ignored by the British Establishment, although he did become a Fellow of the Royal Society.”
I like this sense of tragic whimsy in Wadhams’ writing. Scoresby was a whaler who provided the first scientific analysis of Arctic sea ice in 1820, and whose data led to efforts to reach the Pole, although the first British vessel was forced back by the strong flow of sea ice. In general the Royal Society is immensely prestigious for its superb scientific work, but British class snobbery has immense disdain for mere facts, a sense of contempt that helps to explain why the practical science of climate change gets ignored by the powers that be.

Sealers and whalers continued to track the ice edge, sending their data to the Danish Meteorological Institute from 1872, producing a somewhat patchy historical record of ice extent that showed no clear trends until the recent precipitous collapse. Attention on the Arctic increased with the Cold War as it became the route for missile trajectories between America and Russia, and regular surveys showed summer ice area start to fall from about 1960.

The estimate in the 1980s was a loss of about 3% per decade, but this did not take into account that the ice was also thinning, as Wadhams discovered with his submarine voyages, leading to a paper in Nature published in 1990 showing thinning of 15% between 1976 and 1987. By the 1990s, better measurement methods revealed thinning of a staggering 43% over about 20 years, a volumetric loss of 60%.

Wadhams continues his cantankerous comments about climate modellers, commenting that they failed to recognise the major importance of this finding. Imagine if chicken egg shells thinned by 43%. That was a big factor in the banning of DDT due to its effect on eagle eggs. We are similarly walking on eggshells with the thin Arctic ice, but in this case the shell still protects the whole planet.

Unfortunately, Wadhams was still ignored by climate modellers, who complacently thought the Arctic ice would remain for the rest of this century. The summer minimum in September fully detached from the coasts of Siberia and Alaska for the first time in 2005, producing accelerating collapse, due to the open seas allowing bigger storms to break up the ice and send it out to the Atlantic.

The idea of studying polar ice by submarine sounds dangerous, and indeed it is. In 2007, two sailors on a British polar submarine were killed by an exploding canister, which should have been replaced already, and Wadhams was lucky to escape alive. That was the last British polar submarine voyage.

The relentless downward trend driven by global warming continues. In 2012, the sea ice summer extent that had been stable above ten million square km for the first half of the twentieth century hit a disastrous new low of just 3.4 million, a third of the previous safe figure, with a strange Arctic cyclone breaking off big chunks. Yet modellers still expected several more decades of summer ice, ignoring the range of accelerating interconnected warming feedback amplifiers.

One of these amplifiers of global warming is the huge new areas of open water that enable the polar winds to whip up big waves in previously icy seas. Polar waves were the topic of Wadhams’ PhD in the 1970s, back when science involved field measurement. Travelling on a diesel sub, he used sonar to show how wave energy scatters when it hits the ice. Now satellite tracked wave buoys show that the autumn refreezing is just not happening as it used to, because this wave scattering is so much more extensive, and because of the heat that has accumulated in the water over the ice-free summer months.

Author:  DWill [ Thu Aug 13, 2020 2:52 pm ]
Post subject:  Re: Ch. 6: Sea ice meltback begins

Robert Tulip wrote:
Wadhams continues his cantankerous comments about climate modellers, commenting that they failed to recognise the major importance of this finding. Imagine if chicken egg shells thinned by 43%. That was a big factor in the banning of DDT due to its effect on eagle eggs. We are similarly walking on eggshells with the thin Arctic ice, but in this case the shell still protects the whole planet.

Unfortunately, Wadhams was still ignored by climate modellers, who complacently thought the Arctic ice would remain for the rest of this century. The summer minimum in September fully detached from the coasts of Siberia and Alaska for the first time in 2005, producing accelerating collapse, due to the open seas allowing bigger storms to break up the ice and send it out to the Atlantic.

As you said, Wadhams based a projection on the exceptional melting of 2012, and therefore he asserted that summer ice would be gone by 2020. It will still be there after this month, but if it takes another 10-20 years to be fully gone, that isn't to say we have great breathing space, especially when we're doing relatively little about the problem.

One of the common phrases coming from science is "modelling shows that..."Computer modelling sounds impressive. I had not considered that its best use would be when observation cannot be conducted, or when the data sets are massive. Wadhams and others, though, have done the hard (and sometimes dangerous) work of observation. Modelers should base their work on this primary evidence, but Wadhams observes they don't, in this field.

Author:  Robert Tulip [ Thu Aug 13, 2020 7:24 pm ]
Post subject:  Re: Ch. 6: Sea ice meltback begins

DWill wrote:
[Wadhams] asserted that summer ice would be gone by 2020.

No he did not, at least in this book. It is essential to be precise in such a charged and complex topic. What Wadhams actually wrote was as follows.

Peter Wadhams wrote:
The trend in the PIOMAS data effectively gives us a drop-dead date of about 2020 for summer sea ice. Anyone who wishes to deny this date and replace it by a much later date must explain why the ice volume should deviate above the trend... there is no mechanism in sight to make this possible. (A Farewell to Ice, Ch7 'How do we know that all this will happen')


Too often in climate debate, partisans distort a statement in order to belittle their opponent. I am not suggesting you are doing that here, but it is easy to see in this case how such a careless paraphrase can lead to incorrect impressions. This is something Wadhams says happens a lot.

As he says "the deniers of this trend" include not just the fossil shills but also the IPCC in its supposedly authoritative Fifth Assessment Report of 2013 (not sure how much IPCC has moved since then), you can readily see the scope for distortion. And of course it is hardly surprising that the fossil shills leap to attack the IPCC when it makes claims that exaggerate warming, such as with the glacier melting rate controversy, but completely ignore examples like this where IPCC is shown to ignore data that reveals the warming problem is worse than it says.

Edit to add: The IPCC Special Report on the Ocean and Cryosphere in a Changing Climate from 2019 includes the following farcical complacent comment, which ignores that the actual trajectory is for four degrees of warming, not 2, let alone 1.5.
SROCC wrote:
It is very likely that projected Arctic warming will result in continued loss of sea ice and snow on land, and reductions in the mass of glaciers. Important differences in the trajectories of loss emerge from 2050 onwards, depending on mitigation measures taken (high confidence). For stabilised global warming of 1.5°C, an approximately 1% chance of a given September being sea ice free at the end of century is projected; for stabilised warming at a 2°C increase, this rises to 10–35% (high confidence).

Author:  Robert Tulip [ Fri Sep 25, 2020 12:59 am ]
Post subject:  Re: Ch. 6: Sea ice meltback begins

Arctic sea-ice shrinks to near record low extent

A media report is at https://www.bbc.com/news/science-environment-54211760
A more detailed scientific report is at https://nsidc.org/arcticseaicenews/

The annual minimum for Arctic sea ice occurred on 15 September, with the second lowest area since records began. This year the minimum area was 3.74 million sq km (1.44 million sq miles), 10% more than the record minimum in 2012 when large storms broke up the ice. The minimum this year is less than one third of the annual minimum ice volume seen through the 1980s.

The ice has not continued its previous trajectory toward a 'Blue Ocean Event' with zero ice. September ice volume has been relatively stable since its low point in 2012. It appears the main reason is that the thickest and oldest remaining sea ice is adjacent to the massive Greenland Ice Sheet, while the thinnest ice is in the middle of the Arctic Ocean and close to Russia.

It appears that the Greenland glaciers are cooling the sea ice. The overall annual average ice volume is steadily trending down, but the Greenland ice sheet acts as a refrigerator, so exponential summer sea ice loss has occurred in the regions distant from Greenland, not adjacent to it.

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