"Cool it!", chapter 1: Polar Bears: Today´s Canaries in the Coal Mine?

Specialist publications on the status of polar bears have also been criticised by others, e.g. a paper coauthored by several well-known climate sceptics, some of which receive funding from oil companies (Dyck, Soon, Baydack, Legates, Baliunas, Ball & Hancock, 2007). In a recent paper, this criticism has been rebutted point by point by specialists in the field, see  I. Stirling, A.E. Derocher, W. A. Gough & K. Rode (2008): Response to Dyck et al. (2007) on polar bears . . ,  Ecological Complexity doi: 10.1016/j.ecocom.2008.01.004.

List of errors in Lomborgs text:

GROUNDLESS DEROGATION
Page 5 top, page 6 top and page 7 top: "The World Wildlife Fund actually warns that polar bears might stop reproducing. . ."; "That its population has declined . . has gotten much press. Not mentioned though, is that . . " and "Yet we are told that global warming will make polar bears extinct, possibly within ten years. . "
Error:
Lomborg tries to paint a picture of the WWF as an organisation that issues vastly exaggerated claims. However, the quote on page 5 from Washington Post of what WWF said is not correct. WWF was quoted for saying that bears in Hudson Bay might stop reproducing by 2012. This is a correct citation of what scientists say (except that it should have been only the western Hudson Bay). But Lomborg distorts the citation even further and make us believe that WWF said that polar bears - worldwide - would go extinct within ten years. Actually, when you consult the WWF web pages, you see a very different picture. There is a balanced presentation of what populations are declining, now and formerly, and what populations are increasing, now and formerly. The news story on decline in the Western Hudson Bay is presented as just what it is - one story from one limited part of the distribution range. There is one page on hunting (this version was placed on the internet already when Lomborg was writing his book) stating that the main threat to polar bears remains over-hunting. Actually, you get much better and more balanced information on polar bears on the WWF web pages than the information in Cool it, which was outdated already when Lomborg wrote it. The distortion of what WWF says is so gross, and so evidently deliberate, that this is counted as ablatant error.

FLAW OF CITATION
Page 5: "The Independent tells us . . . "
Flaw:
The source that Lomborg gives does not contain the cited sentence.

FLAW
Page 5: ". . . of the twenty distinct subpopulations of polar bears, one or possibly two were declining in Baffin Bay; more than half were known to be stable; and two subpopulations were actually increasing around the Beaufort Sea."
Flaw:
This information is taken from the 13th specialist meeting in 2001. However, knowledge of population size and trends was still not very certain at that time, and declines because of changed ice cover were not yet clearly evident. Data from the 14th specialist meeting in 2005 are different: out of 19 populations, 2 are increasing, 5 are declining, 5 are stable, and for 7 the trend is unknown due to lack of data. Lomborg should have used the most recent evidence. The proceedings of the 14th specialist meeting were placed on the internet in November 2006. Lomborg has a reference to the polar bear specialist group homepage. This homepage put a message on 15-Dec-2006 telling that the proceedings from the 2005 meeeting in Seattle have been published and can be downloaded. We know that Lomborg was still writing on the polar bear issue in January 2007, so he had time to use the most recent information, but he did not.

FLAW
Page 5: ". . . more than half were known to be stable; and two subpopulations were actually increasing . . ."
Flaw:
This information is taken from the 13th specialist meeting in 2001. The number of populations known to be stable at that time was 8, which is less than half.

FLAW
Page 5: "actually increasing around the Beaufort Sea"
Flaw:
The most recent report says for the southern Beaufort Sea that although the point estimates (1,800 around 1997 and 1,525 after the turn of the century) "suggest a decline in numbers, the overlap of the current confidence interval with the previous point estimate prohibits an unequivocal statistical conclusion . . ". As for the northern Beaufort Sea, the report says that new data will be available in 2006. Until the new estimate appears, no conclusions can be drawn.

ERROR
Page 5: "it is reported that the global polar-bear population has increased dramatically over the past decades, from about five thousand members in the 1960s to twenty-five thousand today."
Error:
This is not true. As evident from the book of  Uspenskii  (reference above), various estimates of the world population from the period 1957 to 1979 range between 10,000 and 20,000, with the 1957 estimate being in the upper part of this range. However, the true figures are not known with any certainty. Lomborg´s only source for the figures is an article in the New York Times, i.e. he has no reliable source. Considering that the estimate for 2001, based on more extensive data, is 21,500 - 25,000, there is probably a slight net increase up to 2001, but no evidence for a  dramatic global population increase.

ERROR
Page 5, bottom: "Contrary to what you might expect . . . the two populations in decline come from areas where it has actually been getting colder over the past fifty years. . "
Error:
The two areas referred to are the Baffin Bay and Davis Streat areas, including the west coast of Greenland. Air temperatures in the latter area have declined during the period 1950-1970, but have increased gradually from 1970 onwards. That is, during the period when the population sizes of polar bears have declined, air temperatures have increased (see this link). At the east coast of Labrador, rises in air temperatures have come later, but they are clearly rising now (Przybylak (2000), cited by Lomborg. What is crucial to the polar bears, is that the sea ice does not break up too early in the summer. Data from 1979 onwards for these regions show that on average, the data of ice breakup has become ever earlier, i.e. the climate has become ever milder, contrary to what Lomborg says. This evidence is presented clearly in the paper I. Stirling & C.L.Parkinson (2006): Arctic 59: 261-275, which has been presented to Lomborg. Climate trends before 1979 are irrelevant, because the trend of the bear populations are not known so far back in time. Thus Lomborg writes something which he knows is irrelevant (before 1979) or wrong (after 1979), i.e. he misleads deliberately.
   It may be added that polar bear populations have been stable in the Southern Hudson Bay, where the climate has been slightly cooling for some period.

(GROUNDLESS DEROGATION)
Page 5, bottom: "Contrary to what you might expect - and what was not pointed out in any of the recent stories - the two populations . . . "
Comment:
Lomborg insinuates that "the recent stories" were not honest, omitting evidence that decline concurs with a cooling climate. But as the climate was actually warming, not cooling, during the periods when polar bears declined, this insinuation is groundless.

FLAW
Page 5 to 6: "Al Gore´s comment on drowning bears  . . in an area housing one of the increasing bear populations."
Flaw:
The episode of four drowned bears was related to a situation where many bears had already problems swimming in open water far from the nearest ice or land. See this link. Specialists say in the recent report (14th meeting) that "The primary concerns for this subpopulation are from climate warming that continues to expand both the expanse and duration of open water in summer and fall." And the population is probably decreasing, not increasing.

ERROR
Page 6, top: ". . the western coast of Hudson Bay. . . since 1981 the population has soared from just 500 . . ."
Error:
Earlier estimates were less certain. Lomborg´s information is from a paper by Stirling, Lunn & Iacozza (1999), which presents a graph indicating that the population estimate for the Western Hudson Bay was about 500 in 1981 and 1,500 in 1985.  Unfortunately, in that paper the graph is presented without explanatory comments. More original data are in the following paper: A. E. Derocher & I. Stirling (1995): Journal of wildlife management 59(2): 215-221. Here, it is seen that the error bars around each point estimate are larger than the variations from year to year. And indeed, the paper says (p. 220): "Poulation size did not show any trend between 1980 and 1992". The estimate is about 1,000 bears for the whole period. Lomborg has also found a graph indicating about 850 bears in 1985 and about 1,200 bears in 1987 (Amstrup 2006). This graph too gives uncertainty intervals, and it is clear from the graph that the difference between the figures of 850 and 1,200 are not statistically significant. Having taught statistics, Lomborg should have been able to understand that the rise is not significant.
    Unfortunately others, including Rosing-Asvid, cited by Lomborg,  have taken the figures literally, without considering that a rise from 500 to 1,500 is impossible, and without considering the uncertainties involved . Over a period of four years, a polar bear population can maximally grow by about 15 %, i.e. if there were 1,500 bears in 1985, there must have been at least 1,300 bears in 1981.
    It is believed that the population was exposed to overhunting before hunting regulations in 1968, and it is believed therefore that it increased especially from the late 1960s and well into the 1970s. But the apparent increases that Lomborg refers to are statistical artifacts.
    Experts corresponding with Lomborg have tried to explain to him how large are the uncertainties and methodological problems involved. So Lomborg should have understood that the low figures for the early 1980s are simply due to statistical variation because of low sample sizes. But he has chosen to neglect these reservations pointed out to him by experts in the field, and has draw his own false conclusions. If he had taken account of known facts on polar bear biology, he would have known that isolated populations can grow by maximally 3-4 % per year, and that growth by immigration from neigbouring populations is very limited. The population increase that Lomborg postulates can impossibly have occurred.

ERROR
Page 6; top: " . . since 1981 the population has soared from just 500, thus eradicating any claim of decline."
Error:
Lomborg knows that evidence right since 1981 points to a decline, because the average body mass (weight) of polar bears, and the sruvival of youngs, has declined steadily in this area since the mid 1980s. This is demonstrated clearly in the paper by Stirling, Lunn and Iacozza (1999) that Lomborg has read. There have been significant declines in the body condition of adult male and female polar bears, and in the proportion of independent yearlings captured during the open water season in western Hudson Bay. Over the same period, the average date of spring break-up of the sea ice in the region has advanced by three weeks, presumably due to increasing spring air temperatures. Lomborg knows about this evidence, but does not want to include it in his story. There is evidence that the changes in body condition and breeding success may also partially be explained by other factors that act only temporarily (Rosing-Asvid 2006, cited by Lomborg), but this does not "eradicate any claim of decline".

FLAW
Page 6: "it means we have lost about 15 bears to global warming each year, whereas we have lost 49 each year to hunting."
Flaw:
With this sentence, Lomborg either demonstrates a blatant lack of understanding of ecology, or purports to lack this understanding. In a stable population, it is possible to obtain a `sustainable yield´, because the population each year produces a surplus of young, some of which will die from natural causes if they are not shot by man. Calculations are made by wildlife biologists to find the size of the `sustainable yield´, i.e. how many bears may be shot each year without causing the population to decline. Permits are then issued to shoot this amount of bears, with the local inuit population receiving most of the permits. However, if conditions get worse, the bears produce less young, and the sustainable yield decreases. That is, the increased melting of sea ice means that the population tolerates less hunting than before. So harvesting the sustainable yield does not imply a lasting reduction of the population (a "loss"), whereas a decline in the size of the sustainable yield is indeed a loss, to the polar bear population and to the people hunting them.

ERROR
Page 6: " In 2006, a polar-bear biologist from the Canadian government . ."
Error:
The biologist referred to is Mitchell Taylor. The quote may be seen in full in this link. He does not work for the Canadian federal government, but for the government of the Nunavat territory, where local interests in allowing large quotas for beer hunting probaly have a greater weight.

FLAW
Page 6, bottom: "we hear vastly exaggerated and emotional claims that are simply not supported by the data."
Flaw:
The claims are not exaggerated, and they are supported by the data.

ERROR
Page 6 bottom: " Yes it is likely that disappearing ice will make it harder . . and that they will incresingly take up a lifestyle similar to that of brown bears . ."
Error:
In the notes, Lomborg writes: "The Arctic Climate Assessment finds it likely that disappearing ice will make polar bears take up `a terrestrial summe lifestyle similar to that of brown bears . .´ ". But here follows the original text in the assessment report (Symon, Arris and Heal 2005 p. 509; Berner is not among the editors): "It is difficult to envisage the survival of polar bears as a species given a zero summer sea-ice scenario. Their only option would be a terrestrial summer lifestyle similar to that of brown bears, from which they evolved. In such a case, competition, risk of hybridization  with brown bears and grizzly bears, and increased interactions with people would then number among the threats to polar bears." Thus, in the cited text, the eventual survival of polar bears on land is presented as a hypothetical possibility, fraught with several difficulites. It is certainly not presented as something "likely".

ERROR
Page 7, top: "But over the past forty years, the population has increased dramatically. . "
Error:
As stated above, this is not true.

FLAW
Page 7, top; ". . and the populations are now stable."
Flaw:
This might have been true up to 2001, but in 2005 it was no longer true.

(COMMENT)
Page 7: "In general, the Arctic Climate Impact Assessment projects that the Arctic will experience increasing species richness . . . "
Comment:
Lomborg usually accuses biologists of focusing on negative trends and ignoring positive trends. But the ACIA report presents in a neutral way positive as well as negative trends. There is no obvious bias. But Lomborg can always twist his text in such a way that we are left with the impression of overly pessimistic environmentalists - also in this case when they make a neutral contribution. On the other hand, Lomborg himself is not neutral here. He only cites those parts of the text on pages 997-998 that deal with positive trends, and ignores all text dealing with various species that will probably decline or go extinct. He ignores that species disappearing from the Arctic will disappear completely from the globe, whereas species that will immigrate to the Arctic already exist elsewhere - that is he ignores the risk that the total number of species on the globe will decline.

Page 7: ". . the plight of the polar bears shows "the need for stricter curbs on greenhouse-gas emissions . . "
Comment:
The cited newspaper article did not exactly say so. The reason given in the article for the need for curbs is rather that the polar bear are indicators of climate change in the Arctic areas, and that these areas provide a bellwether of what´s coming to the rest of planet Earth.

GROUNDLESS DEROGATION
Page 7: "Even if we accept the flawed idea of using the 1987 population of polar bears around Hudson Bay as a baseline . . ."
Flaw:
The idea is not flawed.The population around Hudson Bay did not have an aberrant size in 1987.

FLAW
Page 7, bottom: "Thus, if we really want a stable population of polar bears, dealing first with the 49 shot ones might be both a smarter and a more viable strategy."
Flaw:
This is nonsense due to Lomborg´s lack of understanding of the concept of sustainable yield (as explained above). If we want a stable population, we can shoot 49 bears annually without compromising the stability. If the 49 bears were not shot, a similar number of bears would die from other causes. On the other hand, when the environment becomes less favourable, then the sustainable yield decreases, and the number of bears shot annually will have to be reduced to avoid an acceleration of the ongoing decline.