The “Arctic could become ice-free for the first time in more than 100,000 years, claims leading scientist”, that was the surprising title of an article from the Independent. That leading scientist is Peter Wadhams from the university of Cambridge and it was explained that satellite data showed there was just over 11.1 million km2 of sea ice on June 1st this year, compared to the average for the last 30 years of nearly 12.7 km2. Therefor on track to be ice free this year (or next year) for the first time in more than 100,000 years.
That seemed odd to me. I didn’t know that June 1st was such an important date for the Arctic sea ice. My take was that the most important moment was in September, when the extent of ice is at its smallest. When we look at the NSIDC data I indeed noticed that it is lower than usual. But prizes are awarded at the finish, not in the middle of the race and going from 11.1 to 1 million km2 in roughly three months would require quite a steep drop. Not entirely impossible though, in 2012 ice extent dropped from 12.3 on June 1st to 3.4 at its minimum, but then it has to deviate from its current course soon to get from 11.1 to 1 in the same time frame.
I will keep an eye on the Arctic sea ice in the next couple months.
To me, it would be more interesting to know the reason for these low conditions. Apparently the analysis reported on things like warmer air coming from the South and compacting ice due to currents, but there was no mention about for example El Niño. Could the strong El Niño from 2015 – 2016 have anything to do with this lower than usual extent?
Coming to the subject of this post, I heard the name Wadhams before. Searching that name showed that this was not the first time he predicted an ice free Arctic and the evolution in his predictions was rather interesting. The first of his predictions of an ice free Arctic that I found was from 2008 (my emphasis):
June 27, 2008
It is quite likely that the North Pole will be exposed this summer – it’s not happened before,” Professor Wadhams said.
That was after a previous low in 2007, so can image that the expectation back then was high that Arctic ice was in a death spiral already. Anyway, it is always risky to make a prediction so short in the future. Remedy is to predict further into the future. This was the prediction a year later:
October 14, 2009
Professor Wadhams said: “The Catlin Arctic Survey data supports the new consensus view – based on seasonal variation of ice extent and thickness, changes in temperatures, winds and especially ice composition – that the Arctic will be ice-free in summer within about 20 years, and that much of the decrease will be happening within 10 years.
Sea ice must have been doing okay, in 2010 the ice free Arctic is even further postponed into the future:
March 16, 2010
The prediction quoted above – of an ice-free Arctic within twenty to thirty years’ time – is based on the output of just two of the IPCC models, whose results fit observed data better than those of the combined twelve. Wadhams believes that it’s a reasonably accurate prediction, if a little conservative. “What will probably happen is that the ice will first retreat quite quickly, until in about ten years we are down to a fairly small region north of Greenland and Ellesmere Island, where you have thicker multi-year ice – that’s about a half or a third of the present summer area. Then that will survive longer because it is thicker and might last another twenty years. So twenty to thirty years is a good conservative figure, though I suspect that the ice will go faster than that.”
But what happened after March 2010 that the prediction suddenly lowered to one or two year?
May 12, 2011
The Pan-Arctic Ice-Ocean Modelling and Assimilation System (PIOMAS) which measures ice volume shows that last September there was only a quarter of the ice in the Arctic that there had been in 1979.
Prof Wadhams says in summer “it could easily happen that we’ll have an ice-free North Pole within a year or two“.
At that time the prediction seem to be based on the model of Maslowski and this pinpointed an ice free Arctic a bit later:
November 8, 2011
Arctic sea ice could completely melt away by the summer of 2015, destroying the natural habitat of animals like polar bears, one of Britain’s leading ocean experts has claimed
Prof Wadhams said: “His [model] is the most extreme but he is also the best modeller around.
“It is really showing the fall-off in ice volume is so fast that it is going to bring us to zero very quickly. 2015 is a very serious prediction and I think I am pretty much persuaded that that’s when it will happen.”
Interestingly, it seems to be the volume that was reported on until now in stead of extent, but maybe more on that in a later post.
The predictions stayed the same the next year:
August 27, 2012
Professor Peter Wadhams, from Cambridge University, told BBC News: “A number of scientists who have actually been working with sea ice measurement had predicted some years ago that the retreat would accelerate and that the summer Arctic would become ice-free by 2015 or 2016.
Although some reported optimism that it could be sooner (sea ice was not looking good back then with again a historic low at that time):
September 21, 2012 Arctic Sea Ice: What, Why, and What Next
Peter Wadhams, who leads the Polar Ocean Physics Group at the University of Cambridge, has predicted since 2008 that the Arctic ice could be gone in summer by 2015. He now believes there’s a chance that it could happen even sooner.
Not sure that Wadhams predicted Summer 2015 since 2008. As far as I could see, in 2008 he predicted the ice free Arctic in the same year and in the next two year it was predicted it would take 10-20-30 years. I could only find the Summer 2015 prediction in 2011. That is only 1 year that this prediction was set, not 4. After the deep minimum of 2012, the prediction stayed on the same track:
July 24, 2013
Professor Peter Wadhams, co-author of new Nature paper on costs of Arctic warming, explains the danger of inaction
How long do we have before the Arctic summer sea ice disappears?
Given present trends in extent and thickness, the ice in September will be gone in a very short while, perhaps by 2015. In subsequent years, the ice-free window will widen, to 2-3 months, then 4-5 months etc, and the trends suggest that within 20 years time we may have six ice-free months per year.
Also some mention of a death spiral:
August 2, 2013
But Wadhams is even angrier about another line in that last IPCC report suggesting it could take until the latter part of this century before Arctic summer sea ice disappears almost entirely. The sea ice that covers much of the North Pole always melts a little in summer and then refreezes as winter sets in. Last summer, however, it shrank to its lowest point in more than 30 years, a much more dramatic decline than predicted. Wadhams thinks it more likely that its summer sea ice will vanish as soon as 2015.
“It could even be this year or next year but not later than 2015 there won’t be any ice in the Arctic in the summer,” he said, pulling out a battered laptop to show a diagram explaining his calculations, which he calls “the Arctic death spiral”.
In September 2013 the decreasing ice extent trend stopped and subsequently summer 2015 prediction seemed to be forgotten…
November 2, 2014
“By 2020, one would expect the summer sea ice to disappear. By summer, we mean September. … (but) not many years after, the neighboring months would also become ice-free.”
But came back into the spot lights again (plus some extra margin for when it doesn’t come true):
May 15, 2015
2:37 Interviewer: Is this [changed landscape of the Arctic over the past 30 years] we should be concerned about?
2:40 Wadhams: I am sure. We should be and in fact people are concerned about it. Because what it is preceding is the actual disappearing of the ice and that is something which could easily happen this year or maybe the next couple of years.
This brings it to 2015 – 2017. Since the extent on September 2015 was 4.41 million km2, that prediction failed. But there are of course still 2016 and 2017 to the rescue:
June 5, 2016
Professor Peter Wadhams, head of the Polar Ocean Physics Group at Cambridge University, told The Independent that the latest figures largely bore out a controversial prediction he made four years ago.
“My prediction remains that the Arctic ice may well disappear, that is, have an area of less than one million square kilometres for September of this year,” he said.
“Even if the ice doesn’t completely disappear, it is very likely that this will be a record low year. I’m convinced it will be less than 3.4 million square kilometres [the current record low].
“I think there’s a reasonable chance it could get down to a million this year and if it doesn’t do it this year, it will do it next year.
Sure, I agree with the journalist that Wadhams made that prediction four years ago, but he also predicted until now:
- 2008 (falsified)
- 2 years from 2011 → 2013 (falsified)
- 2015 (falsified)
- 2016 (still to come, but will require a steep drop)
- 2017 (still to come)
- 2020 (still to come)
- 10 to 20 years from 2009 → 2029 (still to come)
- 20 to 30 years from 2010 → 2040 (still to come).
I guess we will continue to hear the story of the ice free Arctic for quite a while. He will have plenty of opportunities to sell this story for years, even decades, to come. He was wrong until now, but apparently nobody seems to bother. Journalists (and the public) can’t get enough of this stuff.