The Great Cooling Of Arctic Sea Ice Projections: Having Been Burned, Scientists Far More Cautious With Projections
Dirk Notz of the Hamburg-based Max-Planck-Institute: Arctic sea ice could again expand in the coming decade By Sebastian Lüning and Fritz Vahrenholt (Translated/edited by P Gosselin) Over the past 30 years Arctic sea ice has shrunk considerably. Although both in 2007 and 2012 negative records were reached, the ice recovered in the years that followed. Former US Vice President and climate activist Al Gore was clearly impressed by the 2007 melt record and so in 2008 he declared the Arctic could be completely ice free by 2013. The year 2013 came and went, but the ice stayed. Using the same alarmist bullhorn, US Senator John Kerry also announced that the Arctic sea ice was set to melt away, read here: The truth is that the threat we face is not an abstract concern for the future. It is already upon us and its effects are being felt worldwide, right now. Scientists project that the Arctic will be ice-free in the summer of 2013. Not in 2050, but four years from now.“ The idea of an ice-free Arctic from both politicians obviously had been whispered to them by IPCC scientists such as Wieslaw Maslowski. The BBC reported here on December 12, 2007: Scientists in the US have presented one of the most dramatic forecasts yet for the disappearance of Arctic sea ice. Their latest modelling studies indicate northern polar waters could be ice-free in summers within just 5-6 years. Professor Wieslaw Maslowski told an American Geophysical Union meeting that previous projections had underestimated the processes now driving ice loss.” Looking back at these completely failed prognoses, one would at least expect a return to reason. But this has not been the case for some. There are still climate alarmist scientists who continue insisting that the Arctic sea ice only has a few years left. They’re dead sure. The same is true with the end-of-the-world. And when the predicted end of the world fails to happen, the goalposts get pushed back, or the focus switches to some other end-of-world scenario. One of the more outspoken believers of the Arctic death spiral is Peter Wadhams of the University of Cambridge. In 2012 he announced to the world the prognosis that Arctic sea ice would disappear within four years. Today, two years later, the trend is in the opposite direction. It doesn’t look good for Wadhams and his prognosis. Now even some of the most obstinate alarmists think the same. For them the apocalyptic visions are really starting to get annoying. During a sea-ice conference in September 2014 in London, Gavin Schmidt had harsh words for Wadhams via Twitter: “Some anticipation for Peter Wadhams. Audience members already crying,” “Wadhams still using graphs with ridiculous projections with no basis in physics,” “Wadhams now onto methane pulse of 50 GT. But no better justified than his previous statements,” and “Wadhams clearly states that there is no physics behind his extrapolations.” The latest prognoses come from James Overland and Muyin Wang, who published them in the Geophysical Research Letters in May, 2013. Here they employ three prognosis approaches which look at the end of the ice in 2020, 2030 or 2040. What follows is the abstract: When will the summer Arctic be nearly sea ice free? The observed rapid loss of thick multiyear sea ice over the last 7 years and the September 2012 Arctic sea ice extent reduction of 49% relative to the 1979–2000 climatology are inconsistent with projections of a nearly sea ice-free summer Arctic from model estimates of 2070 and beyond made just a few years ago. Three recent approaches to predictions in the scientific literature are as follows: (1) extrapolation of sea ice volume data, (2) assuming several more rapid loss events such as 2007 and 2012, and (3) climate model projections. Time horizons for a nearly sea ice-free summer for these three approaches are roughly 2020 or earlier, 2030 ± 10 years, and 2040 or later. Loss estimates from models are based on a subset of the most rapid ensemble members. It is not possible to clearly choose one approach over another as this depends on the relative weights given to data versus models. Observations and citations support the conclusion that most global climate model results in the CMIP5 archive are too conservative in their sea ice projections. Recent data and expert opinion should be considered in addition to model results to advance the very likely timing for future sea ice loss to the first half of the 21st century, with a possibility of major loss within a decade or two.” Other scientists have become more cautious, as they were burned too many times in the past with overly hasty projections. Sea ice scientist Dirk Notz of the Hamburg-based Max-Planck-Institute for Meteorology declared in September 2014, in response to a request made by Pierre Gosselin of notrickszone.com, that because of the variability over the coming decade the ice could just as well expand as it could shrink. Interestingly in the model graphics provided by Notz for the coming decades, there are no ice free polar seas to be seen. What follows is the exact wording of the notable e-mail from Notz to Gosselin: Dear Pierre, Thanks for being in touch, and sorry for the slow reply. I was at a meeting with surprisingly little internet access. Regarding the bet: I’d be very careful to place a bet in either direction, simply based on our understanding of the system from climate-model simulations. These basically say that on short time scales, such as from one decade to the next, internal variability can cause both an increase or a decrease of the ice coverage. To exemplify this, I’ve attached a slide that shows 30-year long trends from our climate-model simulations. There you see 30-year long trends for different start dates in our simulations, which vary wildly. This would even more be the case for 10-year long trends. Hence, I wouldn’t put money on a further decrease of the ice cover in the years to come, nor on the opposite. I’ve also attached a plot showing two of the simulations with our Earth-System Model, which suggest that there might be slightly less sea ice in the next decade, but other simulations show a slight increase on these short time scales. Hence, on time scales such as one decade, the ice cover could well increase a bit (as you are suggesting), but it might also decrease. This depends in my opinion primarily on weather patterns in individual summers – nothing we can predict at the moment. Having said this, however, one of the presentations at the meeting I’ve just been to by Andrey Proshutinsky went in the same direction as you’re suggesting, namely that because of ocean cycles there will be a recovery of sea ice in the years to come. However, I don’t believe this to be a very robust finding that I would put money on at the moment. It’s nevertheless certainly something that we’ll investigate more in the time to come. […] Please let me know if any further questions should come up. Best wishes, Dirk” With all the long-term prognoses we are also naturally interested in how things will develop with Arctic sea ice over the coming year (2015). In her blog Judith Curry provided a forecast Blog in October 2014. She expects the ice in the summer of 2015 to at least reach the extent seen in 2014: And finally, my prediction for 2015 sea ice minima. I predict minimum sea extent will be the same or greater than 2014, with a continued recovery of sea ice volume. I expect continued recovery in the Atlantic portion of the Arctic, with continued low sea ice extent in the Siberian Arctic. My decadal scale prediction is either no trend in sea ice minima or an increase (I do not expect continued decline in the coming decade).” It doesn’t look good for Peter Wadhams and the followers of the climate-alarmism movement.
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