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Lomborg-errors: "Cool it!"
Glaciers
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"Cool it!", chapter 3: Global warming: Our many worries
Melting glaciers, pages 53-59

GENERAL REMARKS

Glaciers worldwide have been receding at an accelerating pace during recent decades, concomitant with the general rise in air temperatures worldwide. During the years 1961-1990, melt water from glaciers and ice caps around the world, excluding Greenland and Antarctica, contributed a total of 0.33 mm per year to global sea level rise. For the years 2001-2004, the contribution was 0.77 mm per year, that is, more than twice (reference: this link).

Lomborg manages to shift focus completely away from this fact, by various distracting excursions. First, he writes about glacier movements several thousand years ago, which is not very relevant to the issue of modern global warming. Second, he omits mentioning of the recent acceleration. Third, he points to changes in precipitation rather than changes in temperature in those cases where it fits his agenda, and only those. Fourth, he mentions only one tropical glacier where recession is due to reduced snowfall, and omits mentioning of all other tropical glaciers, where changes in temperature play a (small or large) role.

Lomborg writes at the bottom of p. 54: "It is clear that part of the temperature increase since then has simply been a result of coming out of the little ice age. It is also clear, though, that we are now seeing a warming trend beyond that, indicating man-made global warming. Both of these warmings have caused glaciers to recede." This passage seems to serve as a sort of guard against accusations that the text is biased - doesn´t Lomborg present both aspects? In reality, however, the text is very biased. A rough count shows that out of c. 195 lines on pp. 53-59, the number of lines dealing with different aspects are as flollows:

Glacier fluctuations are natural, and we can do nothing about them: 87 lines
Glacier fluctuations are due to global warming: 10 lines
Glacier fluctuations are due to both at the same time: 2 lines
Global warming has positive aspects: 28 lines
Global warming has negative aspects: 9 lines
Negative talk about those who see glacier fluctuations as due to global warming: 20 lines

Therefore, in reality, the subconscious message received by the reader will be that glacier fluctuations are a natural phenomenon, and those who see glacier fluctuations as due to global warming, are bad persons. Actually global warming is positive.
Strictly speaking, Lomborg does not say that directly, but with the very biased weighting of different aspects in the text, he has carefully made sure that most readers will receive the unconscious message that he wants.

PAST CLIMATE

Comments to pages 53 - 55 in Cool it.

Since Lomborg wrote `Cool it!´, knowledge about past temperatures has increased, and the pattern presented in the socalled `hockey stick´ curve has been corroborated and extended. A good overview of the most recent evidence may be read here.

It is generally recognized that there were warm periods in the northern hemisphere during approximately the period 900 - 1400, but they were not simultaneous. The relative warmth was not a simultaneous global trend, like the trend we see today. Lomborg cites the reference Hughes & Diaz (1994), but it is worth citing the conclusion of that paper, which is that "These warmer regional periods were not strongly synchronous. . . the avialable evidence does not support a global Medieval Warm Period." And Burroughs (1997), likewise cited by Lomborg, also stresses that the Medieval warm period was not a synchronous trend all over the northern hemisphere. On the page cited by Lomborg, it says: "Again we see a patchy combination which provides little indication as to whether any pronounced global changes were in train." This has an important consequence in relation to the global trend. If the medieval warm episodes are in different regions in different periods, then the global average will show a relatively flat curve, with no marked warmth at any time.

The same is true concerning the Little Ice Age. It is true that there was such a colder period, but the periods of maximum cold were not always the same in different regions, and the cold was not continuous. The period was characterized by short periods (decades) of very cold weather, alternating with other periods of benign weather. For instance, in the book by Le Roy Ladurie,on the page cited by Lomborg, the author not only speaks of the cold 1690s, but also the warm 1680s: "During the 1680s the growing season had been warm and dry and produced, in northern France and England, a series of such superb harvests that the price of wheat had begun to decline. But not for long. In 1687 began the dreadful cold seasons . . ". The same variability is clearly presented in the book by Burroughs, which Lomborg also uses as a source. It says: " The annual figures for the Central England Temperature series confirms the exceptionally low temperatures of the 1690s . . The first striking feature of these records is the sudden warming from the 1690s to the 1730s. In less than 40 years the conditions went from the depths of the Little Ice Age to something comparable to the warmest decades of the twentieth century."

RECEDING GLACIERS

Comments to pages 55 - 57 in Cool it.

Modern recession of glaciers is presented by Lomborg mainly as a consequence of emergence from the little ice age; he does mention that manmade warming contributes to glacier recession, but the recent acceleration in glacier melt is left unmentioned.

Actually, changes in the pace of recession of glaciers worldwide since the mid 19th century are well correlated with known changes in temperature. Recession has been fastest in those periods where temperatures were highest, that is in the 1930s - 40s and after 1980. Around 1970, at the end of a relatively cool period, the recession generally slowed, and some glaciers even advanced. After that, recession has again accelerated. Therefore, what we have been seeing after 1970 can no longer just be understood as the after-effect of having left the little ice age, but rather as a direct effect of rising temperatures. If we were seeing just the after-effects of a change to milder climate that occurred at about 1850, then the recession would be gradually slower as the time lapsed since this past climate change increases. Instead, we are seeing accelerating recession worldwide, which points to a direct relationship to recent temperature changes.

In the tropical zone, there are glaciers in many localitions in South America, three locations in eastern Africa, and one in Irian Jaya (New Guinea). All of these glaciers are receding, and in nearly all cases rising temperatures play a role in this (link). But the only tropical glacier mentioned by Lomborg is that on Mount Kilimanjaro, which is probabaly the only glacier where recession is quite independent of temperature changes. This is a strongly biased and therefore misleading presentation.

GLACIERS FEEDING RIVERS

Comments to pages 57 - 59 in Cool it.

The text on melting glaciers in Himalaya and Tibet (p. 57) is very misleading. A much better text on the subject is a report on glacier retreat in Nepal, India and China, published by the WWF. This is recommended to the reader. According to this report, glaciers in the catchment areas leading to the large rivers in India are melting at an accelerating rate. This means an increased summer-flow in the rivers right now, but as the glaciers dwindle, the waterflow will eventually decrease to below the present level. The trends in annual waterflows are projected to be as follows: In the upper Indus, there will be initial increases of water flow ranging from +14 to +90 % over the first few decades, followed by decreases of -30 to -90 % after 100 years. For the upper part of the Ganga, the change will be +20 to +33 % during the first two decades, and after that a decrease by -50 %. For the lower Ganga, there will be little change. For the Brahmaputra, there will be a drecrease of water flow throughout. The projected changes are potentially quite serious, because about 500 mio. people are dependent on the waterflow in these rivers, not only for households and agriculture, but also for hydroelectric power. In addition, accelerated glacier melting will cause more episodes of sudden floodings due to bursting glacier lakes.

Flaws on particular pages in Lomborgs text:

(COMMENT)
Page 54 top: "In Alaska, the mean temperature was 2-3° warmer in the eleventh century . . "
Comment:
This is correctly cited from Lomborg´s source, but it seems improbable. According to the source, this is based on tree ring data, but according to data which Lomborg has seen (D´Arrigo et al. 2006), there seems to be only one long series of tree ring data from Alaska, and this shows a relatively warm period (approximately like in the mid 20th century) in the tenth century, whereas the eleventh century was considerably colder there.

FLAW
Page 54 bottom and note 330: ". . crop practices changed throughout Europe to adapt to a shortened and less reliable growing season, causing recurrent famines."
Flaw:
The picture painted by Lomborg here is a rather stereotypic picture of a sustained cold period. But what his source (Burroughs) tries to do, is exactly to decompose that stereotype. It says, on the page cited by Lomborg: "This growing body of work shows that . . the real situation is not quite as stark as the simple stereotype suggests." There is no mention of a change in crop practices, and although the recurrent famines are precisely described, it is also stated that the worst famine occurred when there was a series of bad years in an otherwise benign period. It is explained that Malthusian population growth contributed to the famines. Lomborg´s formulation is taken from Reiter (2000), not from Burroughs as indicated.

FLAW
Page 54: "Possibly the worst winter in France, in 1693, is estimated to have killed several million people - about 10 percent of the population."
Flaw:
In Lomborg´s source, on the cited page, the author says: ". . several major food crises. One of these was among the worst famines in the whole seventeenth century: the failed harvest of 1693 caused an apocalyptic, medieval-type dearth which killed millions of people in France and the neighbouring countries." Lomborg´s flaws are: 1) he omits mentioning the decades just before (and just after), when the weather was quite benign. Second, the millions of people that died were not just in France, but in several countries; therefore, the estimation based on the population size of France is not valid. The figure of 10 % does not occur in the source.

FLAW
Page 54: ". . with Lake Superior iced over till June in 1608" .
Flaw:
The source says: "In 1607-8 ice persisted on Lake Superior until June." So whereas Lomborg postulates that the whole lake was covered by ice, the source says only that remnants of ice persisted.

(COMMENT)
Page 55 top: "Al Gore, for example, fills eighteen pages of his book with before-and-after pictures of glaciers.
Comment:
The correct figure is 12 pages, or 16 pages if you include pictures of Kilimanjaro.

(COMMENT)
Page 55: "Bjornbreen . . . has been reborn six times."
Comment:
It is not mentioned here that these variations are ascribed more to variations in winter precipitation than to variations in temperature.

REMARK
Page 55: ". . most glaciers were small or absent from nine thousand to six thousand years ago"
Remark:
The source indicates that the glaciers were short, or in places even absent. This is not surprising, as it is wellknown that temperatures were higher than now during the period 9,000 to 6,000 years ago.

FLAW
Page 55: "When Bjornbreen peaked around 1800, it was actually twice as large . . "
Flaw:
It was only 20-30 % larger, as estimated by combining Figures 10 and 11 in the paper by Matthews et al. The text on page 80 in that paper is that the two first advances of the glacier were "almost as large" as the advance during the little ice age.

FLAW OF OMISSION
Page 55 bottom: Modern recession of glaciers is presented mainly as a consequence of emergence from the little ice age; Lomborg does mention (p 54) that manmade warming contributes to glacier recession, but the recent acceleration in glacier melt is left unmentioned.
Flaw:
Changes in the pace of recession of glaciers worldwide since the mid 19th century are well correlated with known changes in temperature. Recession has been fastest in those periods where temperatures were highest, that is in the 1930s - 40s and after 1980. Around 1970, at the end of a relatively cool period, the recession generally slowed, and some glaciers even advanced. After that, recession has again accelerated. Therefore, what we have been seeing after 1970 can no longer just be understood as the after-effect of having left the little ice age, but rather as a direct effect of rising temperatures. If we were seeing just the after-effects of a change to milder climate that occurred at about 1850, then the recession would be gradually slower as the time lapsed since this past climate change increases. Instead, we are seeing accelerating recession worldwide, which points to a direct relationship to recent temperature changes. During the years 1961-1990, melt water from glaciers and ice caps around the world, excluding Greenland and Antarctica, contributed a total of 0.33 mm per year to global sea level rise. For the years 2001-2004, the contribution was 0.77 mm per year, that is, more than twice (reference: this link).

(COMMENT)
Page 55 bottom: "The best-documented overview of glaciers shows that . . "
Comment:
The reference (Oerlemans 2005) is not the most comprehensive overview over glaciers. It is heavily biased towards northern hemisphere glaciers, and includes very few glaciers in the tropics and on the southern hemisphere; see the criticism in this link.

FLAW OF OMISSION
Page 55 bottom: The only tropical glacier mentioned by Lomborg is that on Mount Kilimanjaro.
Flaw:
In the tropical zone, there are glaciers in many localitions in South America, three locations in eastern Africa, and one in Irian Jaya (New Guinea). The vast majority of these glaciers are receding, and in nearly all cases rising temperatures play a role in this (link). But Lomborg mentions only that single place where glacier recession may probably not be due to rising temperatures (whereas Al Gore mentions also South American glaciers). This is a strongly biased and therefore misleading presentation.

FLAW
Page 756 top: "This is more than it has lost in the seventy years since"
Flaw:
The text is misleading. Counting from 1880, the loss up to 1936 was 55 %, i. e. more than half. Of course the loss after that could impossibly be more than that, because in that case more than two halves would have been lost, i.e. more than 100 %. After a period with high snowfall just before 1880, the glacier declined much up to 1912. But since 1912 the loss of area per year has been nearly constant, and the percentage loss per time unit of time has been ever increasing.

(COMMENT)
Page 56: "Kilimanjaro has not lost its ice to increasing temperatures . . "
Comment:
This may or may not be correct. See more about this on Lomborg-errors´ page on Kilimanjaro.

Notice that when a glacier retreats (Kilimanjaro), Lomborg stresses the importance of precipitation rather than temperatures, whereas when a glacier expands (Bjørnbreen), he does not mention precipitation.

(BIASED DEROGATION)
Page 56: "This is the price we pay if climate change is allowed to go unchecked."
Flaw:
The statement from the Greenpeace press release is here placed in a changed context so that it looks as if "this is the price" refers only to the disappearing snow on Kilimanjaro. But in the press release, the "price" includes crippling drought and water supplies at an extremely low level in the Atlas mountains, and in Africa in general more extreme droughts and floods, widespread agriculture loses, and increased infectious diseases. In the lower part of page 72 Lomborg tries to give the impression that Western opinion makers are only concerned about the Kilimanjaro ice cap. He knows from the press release that Greenpeace expresses concern for the welfare of the African people, but he manages to give the impression to the reader that the Greenpeace opinion makers care only for the ice cap, not for the real needs of the people.

ERROR
Page 58: " . . providing more water to many of the poorest people . . "
Error:
The facts presented in the footnote are not directly wrong, but they are utilised to reach a false conclusion. The first reference (Singh et al. 2006) deals with the Dokriani glacier which covers 7 km² out of a total glacier area of c. 38.000 km² in the Indus-Ganga-Brahmaputra basins. This glacier has lost about 20 % of its volume from 1962 to 1995, and the loss has accelerated since then. It is no wonder that with rising temperatures, the run-off from this single glacier during summer is projected to increase by 28 %, simply because the glacier is melting away and will probably have disappeared in less than 100 years. This story, however, deals with only a minute fraction of the catchment area. Much more important is the information in Singh & Bengtsson (2004), likewise cited in the note, that the summer run-off will decrease from catchments that are covered by snow during only parts of the year. Now, such catchments make out about 30-40 % of the total mountainous area of the Himalaya, whereas glaciers make out only c. 17 %. Thus, overall, the increased melting of glaciers will be more or less counteracted by decreased run-off from snow-covered areas. Except for a few decades, there will not be more water, but less water, in the rivers, especially in the most important period in summer.
Lomborg´s text on this subject is so misleading that it is counted as an error.
Comment: In January 2010, the media have written much about a statement in a WWF report that the glaciers may be completely gone by 2035. However, this is not what the WWF report says. It cites another report from 1999 which makes this statement. The original data presented in the WWF report say otherwise.

ERROR
Page 58: " . . increasing water availability throughout the last centuries, possibly contributing to higher agricultural productivity. "
Error:
The source Lehmkuhl & Owen does not mention agricultural productivity. Instead it says on the retreat of Tibetan glaciers: "Such conditions clearly pose a serious threat to the water resources and environment throughout Central Asia"; and on Himalyan glaciers: "Presently retreating glaciers pose serious threats to water resources on the Indian subcontinent as well as hazards such as those from glacial lake outburst floods that are common as glaciers retreat."

ERROR
Page 58: " Thus, global warming of glaciers means that a large part of the world can use more water for more than fifty years . . "
Error:
The source (IPCC) says: "Schneeberger et al. (2003) simulated reductions in the mass of a sample of northern hemisphere glaciers of up to 60 % by 2050. As these glaciers retreat due to global warming, river flows are increased in the short tem, but the contribution of glacier melt will gradually decrease over the next few decades." Thus, the run-off from glaciers will decrease in a few decades from now. The people on the northern hemisphere (especially in Asia) cannot use more water for a period of 50 years from now.

ERROR
Page 59: " . . the summer runoff in the rivers Hunza and Shyok has decreased about 20 %."
Error:
Lomborg has misunderstood the text in his source. The figure of 20 % is the decline in waterflow that was predicted on the basis of temperature changes. The actual waterflow was reduced by more than 20 % in one of the rivers, but fairly constant in the other river.

ERROR
Page 59 bottom : " . . prepare for when the rivers revert to "normal" water flow, but with more in the winter, less in the summer"
Error:
The annual river flow is not projected to revert to "normal", but rather to be permanently decreased (WWF report referred to at the top of this page). By the way, what is important is the water flow in the summer season. Lomborg does not explain how it should be possible that water flowing in the rivers during winter should be stored and kept until summer.