One of the reasons why it is extremely unlikely that climate scientists are engaged in some kind of ‘warmist’ conspiracy – a central charge of global warming ‘sceptics’ – is that the scientific method is at its best inherently self-correcting. Those who are the first to spot and highlight errors and exaggerations are generally not non-expert campaigners from the outside, but scientists themselves. So it was with the Times Atlas mistake on Greenland this week – which I think represents a victory for science which should strengthen the case for taking climate change seriously.
As Geoffrey Lean points out in his Telegraph column, the two most reputable scientific authorities on Arctic Ice – the Scott Polar Research Institute at Cambridge University and the National Snow and Ice Data Centre in Boulder Colorado – both “swiftly denounced” the claim by the Times Atlas (in a press release) that 15% of the area had disappeared from Greenland’s ice sheet since the previous edition of the atlas was published 12 years earlier. (The true figure is more like 0.05%.) Whilst some sceptics predictably made hay, the weight of the scientific establishment was quick to respond.
Of course, no-one would have given much space to the story had it not been for the various other climate-related ‘-gates’ that have so far taken place, Himalayagate in particular. That one was more significant, because it included a mistake in an IPCC report – but it too was also discovered and publicised by a scientist, Professor Graham Cogley from Trent University in Canada. Moreover, in both these cases, the error originated outside the scientific community – in the Times Atlas case by an over-enthusiastic press-release writer (and presumably by the non-specialists who compiled the atlas), and in the Himalayagate case in a WWF report which made its way (but should not have done) into the IPCC’s Working Group II. (Mike Hanlon at the Daily Mail has by far the best blow-by-blow account of what actually happened in Atlasgate that I have found.)
Kudos also goes to the Science Media Centre, which brought attention to the story and helped round up specialists to give quotes and expert perspective to the media. Whilst sources in the SMC tell me that some are unhappy that yet another ‘-gate’ has been coined and publicised, possibly further threatening to undermine public confidence in climate science, I entirely support their decision to get the truth out there. No-one should defend an inaccurate statement simply because it holds a particular party line.
To give proper credit where it is due, I will give the rest of this post over to the full quotes from three experts, only small portions of which made it into the key media pieces.
Dr Jeffrey S. Kargel, Senior Research Scientist at the University of Arizona:
“The Times Atlas maps have been publicised in the media far and wide. But make no mistake: this is not what is happening, this is not science, and this is not what scientists are saying. Greenland specialists have documented what is actually happening in Greenland, and it involves some incredibly rapid changes, mainly increasing melting, thinning, and retreat; and slight thickening in some sectors, but overall Greenland is a story of massive, rapid retreat. Special dynamics are at play, and probably climate warming as well.
“However, these new maps are ridiculously off base, way exaggerated relative to the reality of rapid change in Greenland. I don’t know how exactly the Times Atlas produced their results, but they are NOT scientific results.
“Just like IPCCs ‘2035’ (one key, massively wrong paragraph), a number like 15% ice loss used for advertising the book is simply a killer mistake that cannot be winked away. Worse for science, this is not a scientific error, but it could be perceived as one once it is corrected – unless scientists make it clear that this is errant and not of science origin right from the outset.”
Prof J. Graham Cogley, Professor of Geography at Trent University, Ontario, Canada:
“Fortunately the mistake about the Greenland Ice Sheet is much more obvious and indefensible than the Himalayan error. In the aftermath of ‘Himalayagate’, we glaciologists are hypersensitive to egregious errors in supposedly authoritative sources. Climate change is real, and Greenland ice cover is shrinking. But the claims here are simply not backed up by science. This pig can’t fly.
“There are various ways to quantify the scale of the mistake. For example the global average rate of glacier shrinkage is somewhere near to 0.2% per year, but that number is heavily influenced by very small glaciers. Glacier shrinkage on the global scale is difficult to grapple with, but one clear conclusion is that smaller glaciers shrink much faster (in percentage terms) than bigger ones. The Greenland Ice Sheet is the second biggest glacier of all, and the Times Atlas’ contention that it has lost 300,000 sq km in the past 12 years, that is, at a rate of 1.5%/yr (because its nominal area is 1.7 million sq km), would be very surprising indeed if it could be validated. The best measurements in Greenland, which cover only part of the ice sheet, suggest that 1.5%/yr is at least 10 times faster than reality. It could easily be 20 times too fast and might well be 50 times too fast.
“In fact, what may have happened is that somebody, somewhere, has examined a satellite image and has mistaken the snowline for the ice margin. Snow is much brighter than bare ground, but it is also a good deal brighter than bare ice, of which there is quite a lot in summer around the margin of the Greenland Ice Sheet.”
Dr Poul Christoffersen, Glaciologist at the Scott Polar Research Institute (SPRI), University of Cambridge:
“A recent media release accompanying the publication of the 13th edition of The Times Comprehensive Atlas of the Worldstated that the Atlas is ‘turning Greenland ‘green’. Scientists from the Scott Polar Research Institute were extremely puzzled by this statement and the claim that ‘For the first time, the new edition of The Times Comprehensive Atlas of the World has had to erase 15% of Greenland’s once permanent ice cover – turning an area the size of the United Kingdom and Ireland ‘green’ and ice-free’. At the SPRI we believe that the figure of a 15% decrease in permanent ice cover since the publication of the previous atlas 12 years is both incorrect and misleading.
“We compared recent satellite images of Greenland with the new map and found that there are in fact still numerous glaciers and permanent ice cover where the new Times Atlas shows ice-free conditions and the emergence of new lands. Furthermore, the low-lying fringe of the main ice sheet appears to be shown as land, not ice. We concluded that a sizable portion of the area mapped as ice-free in the Atlas is clearly still ice-covered.
“It is regrettable that the claimed drastic reduction in the extent of ice in Greenland has created headline news around the world. There is to our knowledge no support for this claim in the published scientific literature.
“We do not disagree with the statement that climate is changing and that the Greenland Ice Sheet is affected by this. It is, however, crucial to report climate change and its impact accurately and to back bold statements with concrete and correct evidence.
“A close inspection of the new map of Greenland shows that elevation contours are noticeably different to the contours in a older map. My colleague Toby Benham, a scientist at the Scott Polar Research Institute, was able to reproduce these contours using ice thickness data. It appears that the Times Comprehensive Atlas of the World may have used 500m ice thickness to map the ice sheet margin. If so, it is obviously an incorrect and flawed procedure.
“The volume of ice contained in the Greenland Ice Sheet is approximately 2.9 million cubic kilometres and the current rate whereby ice is lost is roughly 200 cubic kilometres per year. This is on the order of 0.1% by volume over 12 years. Numerous glaciers have retreated over the last decade, capturing the attention of scientists, policymakers and the general public. Because of this retreat, many glaciers are now flowing faster and terrain previously ice-covered is emerging along the coast – but not at the rate suggested in The Times Atlas media release.”