Lomborg-errors: "Cool it!"

Temperatures on Greenland and Antarctica  
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 Comments to pages 78 - 86 in Cool It!

To those who want a recent overview of the subject, I may recommend:
A. Cazenave & W. Llovel (2010): Contemporary sea level rise. Annual review of marine science 2: 145-173.
I. Allison et al. (2009): Review: Ice sheet mass balance and sea level. Antarctic science 21 (5): 413-426.
I will also recommend reading the chapters on Greenland and Antarctica in Howard Friel (2010): The Lomborg Deception.

 GENERAL COMMENTS:
 
Lomborg´s text on Greenland and Antarctica is very misleading. He tries in all possible ways to downplay the increasing contribution of melting ice masses on Greenland and Antarctica to the rise of the global sea water level. At the time of his writing, it was still somewhat uncertain if ice melt was really accelerating. Papers of more recent origin, as those referred to above, give a more unequivocal picture of accelerating net mass loss from Greenland, and a net mass loss from Antarctica that may also be accelerating. 
Even on such a small detail as the populations of Adélie penguins, Lomborg does not pass the chance to bias his text, citing information about a population that is increasing, but omitting what he has read about another population that is declining. This once more corroborates how pervasive Lomborg´s bias is.


 JAMES HANSEN´S PROJECTIONS:
 
Lomborg misrepresents James Hansen´s claims about possible future sea level rise. Hansen says that the last time that the Earth was 3° C warmer than today was three million yeras ago, when sea level was about 20 m higher than now. So he - correctly - draws the conclusion that when man-made global warming increases the temperature by 3° C, then there may eventually be established a situation with a similarly high sea water level. The question is then how fast the sea level could rise up to that level. Again referring back to events from Earth´s history he says that at the end of the last ice age, sea level rose by 20 m in four centuries, i.e. 1 m for every 20 years, so this represents a possible upper limit of how fast things could happen.
What arguments does Hansen have that sea level rise could be so much bigger than projected by nearly all scientists? His main argument is that existing model studies on the mass balance of ice sheets consider only the local transfer of heat energy. This is also true for those models that include dynamic glacier responses. However, Hansen´s argument is that melting does not require local heat transfer. If melt water enters the base of the ice sheets and lubricates the underside, then ice sheets could move faster, and much more ice would break off and drift into the ocean, without having to receive heat to melt. When they drift southward, they could receive heat from ocean water there, and melt only then. That is, the logical flaw made by other scientists is that they assume that melting must happen locally, when in fact melting could happen much further south, after the ice berg has drifted away. Hansen argues that the imbalance of heat transfer to and from the planet is sufficient for melting the icebergs.
Hansen´s projections are discussed by Allison et al. (2009, p. 421), referred to above. Here it is stated that a 5 m sea level rise in a century would require that outlet glacier flow rates increased to rates that are glaciologically infeasible. Hansen, being no glaciologist, has not been aware of this limitation, and therefore has bot paid due regard to the fact that the number and size of glaciers now is smaller than at the end of the last ice age. Instead of 5 m, it is argued that sea level rise by 2100 might be in the range 0.8 to 2.0 m, with 0.8 m regarded as the most plausible. Still, this is much more than the 0.3 m estimate that Lomborg favours.

 TEMPERATURES ON GREENLAND:
Lomborg writes (p. 83) that 1941 is still the varmest year recorded on Greenland, and that the 1930s and 1940s still are the two warmest decades there.
    In response to this, John Cappelen, meteorologist at the Danish Meteorological Institutet, DMI, says that the truth is more complicated, because Greenland is large, and the trends are not the same at the seven stations where temperatures have been followed. He also says that at the east coast, 2003 is the warmest year on record, whereas at Nuuk (the "capital", situated in south west Greenland), 1941 and 2003 were equally warm. Altogether, the record year is 2003 rather than 1941.
     The temperatures for three weather stations at the west coast of Greenland are to be found on the internet here. The average for Nuuk was +0.83° in 1941, and +0.51° in 2003, i.e. slightly lower. So Lomborg is right as to the west coast of Greenland, but not as to Greenland in total.
   It may be added that the extent of ice melting on Greenland is steadily increasing, see here and here. The most recent information is that the extent of melting reached a new record in 2007, and that air temperatures above the ice are have increased by about  4° C since 1991, see this link.
    Remember that melting consumes heat energy and tends to lower temperatures. If you put a clump of ice in a jar and supply a heat source to melt the ice slowly, the temperature in the jar will remain constant - at exactly 0° C - as long as there is still ice left in the jar. It is only when all ice has melted that water temperatures start to rise. So if there is a lack of local temperature rise at the weather stations at the coast, this cannot be used as an argument that there is no increase in ice melting.
   The temperature trends for Greenland are not typical for the whole arctic region, as is evident in Przybylak (2000), cited by Lomborg.
   A recent overview over changes in Greenland in air temperatures, precipitation and melting is found in a report by Hanna et al. (2007).


ANTARCTIC TEMPERATURES :

Lomborg writes (p. 84) that the only part of Antarctica that is warming is the west Antarctic peninsula which makes out only 4  % of the total land area; the remaining 96 % has become colder. But this is not true.
    Temperatures for those Antarctic weather stations with the longest time series are found at this link. It is seen here that since the mid 20th century, annual temperatures have increased significantly at the west Antarctic Peninsula and in one coastal station on mainland Antarctica. At all other weather stations, including the South Pole, there is no significant trend. In a few stations there is a significant negative trend for autumn temperatures, but not for annual temperaturs.
    Others have said the same as Lomborg, viz. that 96 % of the Antarctic continent is cooling. This information goes back to a paper by Peter Doran et al. in 2002 in Nature (link). They found (by a different type of analysis) that 58 % of Antarctica had cooled from 1966 to 2000, especially regarding autumn temperatures, whereas the rest, i.e. 42 %, had warmed, including the west Antarctic peninsula that makes out 15 % of the area.
   The cooling of parts of the continent is partially due to the ozone hole. According to Doran, as the ozone hole heals - thanks to worldwide bans on ozone-destroying chemicals - all of Antarctica is likely to warm with the rest of the planet.
    The summary of the paper in Nature pointed out how the cooling trend posed challenges to models of Antarctic climate. American newspaper and television reports focused on this part of the paper, and claimed that these scientific findings ran counter to the theory of global warming. Since then, climate skeptics have cited this information over and over again. Although the scientists have written rebuttals and explained that the media have misunderstood the information, the misinsterpretation has quickly become legend among skeptics, and is cited ever more often. A refutation written by Peter Doran in The New York Times may be read here.

THE LARSEN-B ICE SHELF

Critics pose that the breakup of ice shelves is not due to man-made global warming, because these ice shelves have disappeared before. This criticism is unjustified. The Larsen-B ice shelf has existed without interruption since the ice age (Domack et al. 2005, Curry & Pudsey 2007), and its breakup is ascribed to man-made global warming (Marshall et al 2006). Also the IPCC report (4AR wg1 paragraph 4.6.3.4) says: " . . the ice shelf changes have resulted from environmental warming . . "" Before the 2002 breakup of the Larsen B Ice Shelf, local air temperatures had increased by more than 1.5°C over the previous 50 years .. increasing . . formation of large melt ponds on the ice shelf. These likely contributed to breakup . . ".

PENGUINS IN DANGER?

Lomborg criticises p. 86 the way that the decline of a population of emperor penguins is presented in Al Gore´s  book "An Inconvenient  Truth". However, as explained on the Lomborg-errors page on Al Gore, for page 178 in Gore´s book, there is very little flaw in Al Gore´s text. On the basis of data from G.L. Kooyman, Lomborg infers that there may have been increases in certain emperor penguin populations on the Ross ice shelf; however, a new paper co-authored by Kooyman states that the colonies referred to have had no significant changes up to now, except that one out of six colonies (one not referred to by Lomborg) has had a small increase. Also, new information from 2009 says that the studied colony of emperor penguins is expected to decline very much during this century because fo changes in sea ice (Jenouvrier & Caswell (2009): Proceedings national academy of sciences USA 106(6): 1844-1847).
As to Adélie penguins, which require winter pack ice, Lomborg only talks about increase, referring to a site in east Antarctica. But, according to WWF, the species is severely declining in some places and increasing in others (link). One of the references that Lomborg has read (Vaughan 2001) talks about a colony that has persisted by at least 600 years, but which is now declining. Lomborg omits to mention that.

Flaws on particular pages in Lomborgs text:


 TEMPERATURES ON GREENLAND


FLAW
Page 78 bottom: "However, as the world warms, Antarctica will not noticeably start melting . . . actually be accumulating ice . . .  "
Flaw: This is not true, and it relies on Lomborg´s selective reading of his sources. See the review articles at the top of this page for better and more recent information.

FLAW
Page 79: "The longest studies from the early 1990s till 2002 show that . . . "
Flaw:
The reader gets the impression that it is good to have a long study (so that random variations from year to year cancel out). However, this is not so in this case. The evidence is that the Greenland ice cap was approximately in net balance during the 1990s, but that the net mass balance became increasingly negative during the years from 2000 onwards. That is, the process of net loss of ice has been rapidly accelerating during the most recent years. The "longest study" referred to covers the period 1992 to 2003, that is mainly the period before ice loss accelerated. The results are therefore no longer representative of what happens today.

(COMMENT)
Page 79: "(actually slightly gaining mass)"
Comment:
In spite of increased  precipitation  on south-central  Greenland, which causes an increase in the thickness of the ice of about ½ m per year, all the most recent studies, dealing with the situation in the 2000s, agree that  this does not compensate for the increased melting of glaciers at the coast. The overall mass balance is negative. Lomborg refers in his note 398 to two studies (both utilising the same primary data) indicating that during the 1990s, there was slight mass gain overall. For a discussion of these studies, see this link. The studies used a method where changes in ice thickness in the coastal ranges could not be fully reliably estimated. Thinning of the margins of the ice are very important for the overall mass balance, and it is probable that ice loss along the coasts was underestimated.

(COMMENT)
Page 79: "However, this estimate is only for two years . . . "
Comment:
After having written that the Greenland ice was slightly gaining mass during the 1990s, Lomborg goes on to say that during the years 2002-2005, there was a net loss of mass. But he tries to downplay the significance of this fact. First by stating that this situation lasted only for two years, and that it is difficult to say if it indicates the start of a long-term trend (his note 401). Second by pointing out that the accelerating glaciers had decelerated again by 2006 (note 402). Third by stating that the latest estimate is that the contribution to the rising of the sea water level is only small (note 403). And fourth by citing a reference (note 405) that the present high level of melt-off will not be sustainable on the long term, for lack of ice that can melt.
    A comment to this is that the sudden large discharge of ice in 2004 and 2005 was due to some rearrangement of the structure of the largest glaciers in southeast Greenland (Helheim and Kangerdlussuaq)*. The rate of ice discharge from these glaciers returned in 2006 to "near the previous levels" (Howat et al. 2007, note 402), which means that there was still a net mass balance like in the years between 2000 and 2004. But ice disappears not only by the calving of icebergs at the mouth of glaciers; it disappears also by runoff of meltwater, and this runoff contributed a relatively large mass loss in 2006 (link). And in 2007, the melt extent on the Greenland ice sheet broke the 2005 summer melt record by 10 percent, making it the largest ever recorded (link). When the weight of the ice is reduced, this causes some uplifting of the land upon which the ice rests. Measurements of this uplifting in southeast Greenland indicates an increased disappearance of  ice for the whole period 2001 to 2006 (Khan et al 2007). If the trend seen during 2001-2006 continues, disappearance of the Greenland ice will contribute 60 cm to the sea level rise during this century (link), i.e. 6 mm per year, which is much more than the most recent estimate cited by Lomborg.
     Nobody knows what will actually happen. What we know is that there has been a marked acceleration in recent years of ice discharge into the sea from glaciers, and a slightly rising trend in meltwater runoff. This acceleration is just what would happen if the climate predictions came true. Although there will of course be some variability from year to year, the long-term trend must be affected by the reduced icecover on the Arctic Sea adjoining east Greenland, which will tend to increase air temperatures and glacier flow rates. Up to now, as is evident from the papers referred to at the top of this page (Cazenave; Allison), the contribution form Greenland to sea level rise has been accelerating all the time.
    The important recent trends - marked acceleration of ice loss - is downplayed so much by Lomborg that the reader will think: There is nothing to fear. It may have been Lomborg´s attention that the reader should think just that.

*Note: In many internet articles, there is a confusion between Kangerdlugssuaq, which is the large glacier in east Greenland, and Kangerlussuaq, which is the main airport in west Greenland, with the nearby Russell Glacier.

FLAW
Page 79 bottom: " . . . the 0.7 mm result - which, as we shall see, is an absolutely extreme outlier . . "
Flaw:
The paper by Chen, Wilson & Tapley (2006) states that estimated total ice melting rate over Greenland is -239 ± 23 cubic kilometers per year, mostly from East Greenland. According to the authors, this estimate agrees remarkably well with a recent assessment of -224 ± 41 cubic kilometers per year, based on satellite radar interferometry data. That is, this estimate is not a lonely outlier. More recent information is that after 2004, the loss has been about 300 cubic kilometres per year, a relativley new estimate of Greenland´s contribution to see level rise is 0.5 mm per year, see this link. And a very new article has 0.75 mm per year after 2006
(van den Broeke et al. (2009): Science 326: 984-986.)


ERROR OF CALCULATION (IN LOMBORG´S DISFAVOUR)
Page 79 bottom and note 404: " . . . this would still mean that his 20 feet of sea level increase would take a thousand years."
Error:
Note 404 has: "0.7 mm per year in a thousand years is 7 m." But no - it is 0.7 m. So a correct calculation would tell that the 7 m rise would take ten thousand years. Apparently, this makes Lomborg´s argumentation ten times stronger. Actually, however, this just illustrates that the idea of this calculation is wrong, because it presupposes that the rate of melting would be constant at the present level. But we expect the rate of melting to accelerate, a process that has only just begun.


FLAW
Page 80 top: " . . . this high level of melt-off would not be sustainable for longer periods . . . "
Flaw:
The reader must understand from Lomborg´s text that a rate of 0.7 mm per year is not sustainable for longer periods. However, the paper referred to in note 405 deals with a scenario extending over 3,000 years, and in the first part of that long period, there will - under certain circumstances - be a contribution to the sea water level of 5 mm per year. It is this high level of 5 mm per year that is not sustainable for a period of several thousand years, simply because in the end of the period, little ice will remain.


FLAW
Page 80 top: "In an overview of the main models, Greenland´s contribution over the coming century . . . . "
Flaw: Lomborg refers to a paper by Oerlemans et al. (2005). It reports runs with five climate models, few or none of which are AOGCMs (i.e. they do not include both atmosphere and ocean). They are all performed on IPCC´s B2 scenario, in which the emission of CO2 grows considerably more slowly than what is actually the case at present. More importantly, "the dynamic response of glaciers is not considered", i.e. the types of acceleration of glaciers that is seen recently are disregarded. Therefore, the model outputs have less melting than what may actually be expected. Lomborg´s term "all the major models" suggests to the reader that all likely outcomes are covered by the study, which is not the case, as it deals only with the B2 scenario.FLAW
Page 80: "Hansen has gone publicly on the record . . to say that with the business-as-usual scenario we will see a collapse . . . causing a sea level rise . . . "
Flaw: This is not precisely correct. Hansen wrote as follows: "How much will sea level rise with five degrees of global warming? Here too, our best information comes from the Earth's history. The last time that the Earth was five degrees warmer was three million years ago, when sea level was about eighty feet higher." . . . and  "The only question is when the collapse of these sheets would begin. The business-as-usual scenario, which could lead to an eventual sea level rise of eighty feet, with twenty feet or more per century, could produce global chaos . . . ". So Hansen says that the business-as-usual scenario could lead to an eventual rise. Lomborg changes Hansen´s words to become that we will see a rise.

FLAW
Page 80: "Hansen reviewed Gore´s book very favourably in New York Review of Books . . . "
Flaw: Lomborg suggests to the reader that Al Gore and James Hansen work closely together. However, in Hansen´s review of Al Gore´s book, he tells nearly the opposite (near the end of the review). By the way, there is an error in Lomborg´s reference. The reference Hansen (2006) should end with . . . articles/19131.

FLAW
Page 80: "Yet, his own central reference on the matter claims . . . "
Flaw: No, the paper referred to is not Hansen´s central reference. On the contrary, Hansen mentions that the paper projects an extra sea level rise of only 0.6 - 6.6 cm, whereas he himself gives arguments why the rise would be larger.

FLAW
Page 80 and note 411: ". . . claims that Greenland will contribute to a sea level increase of 0.6-6.6 cm till 2100"
Flaw: Lomborg´s main text is wrong, but his note has it more correct: the 0.6 - 6.6 cm rise is an additional rise on top of what is projected from mass balance studies. It is unclear if Hansen has read it wrong, his text is not completely clear on that point.

FLAW:
Page 80 bottom and _Figure 21: "If we look at Figure 21 we see the results of all models . . ."
Flaw: Figure 21 is taken from the reference Gregory & Huybrechts (2006). However, this paper suffers from the shortcoming that it does not include dynamical responses of glaciers. It says in the first paragraph: "Such accelerated flow leads to increased ice discharge into the ocean, but the relevant dynamical processes are not properly understood nor included . . . This therefore represents an important uncertainty for predictions of sea level, but one which is beyond the scope of this paper to address." So the Gregory & Huybrechts paper does not deal with all contributions to sea level rise. Actually, the present state of knowledge (2010), as stated in the papers cited on top of this page, is that Greenland as well as Antarctica give a net contribution to sea level rise. Lomborg is aware of this. His note 414, which refers to page 1727 in Gregory & Huybrechts, reveals that. And a few lines further above, in his note 411, he has stated that on top of this there is an additional contribution due to dynamic glacier responses on Greenland, which in a 2X CO2 scenario may be 6.6 cm per century, or  0.66 mm per year, and which could very well be even larger, if the present trend in CO2 emissions continues. When we study the vertical scale in the figure, we see that such an extra contribution would change Lomborg´s conclusions. Because Lomborg is aware of the caveat, but does not include it or mention it, this is deliberately misleading.
Furthermore, it gives a wrong impression to use the term "all models", because the reader will easily misunderstand this to imply all plausible scenarios. But the models have been run only on the A1B, A2 and B1 scenarios, and thus have omitted the A1FI scenario which seems to be closest to what actually happens.
The vertical scale in the figure has -2 where it should read -1.

FLAW:
Page 80 bottom - page 81: " . . . but this is only possible in a model where CO2 rises between two and four times higher . . ."
Flaw: Here Lomborg refers to a paper by Parizek & Alley that estimates the possible extra melt of Greenland ice that may occur if dynamic response of glaciers turns out to be important. The estimate is that this may contribute with up to 20 cm of extra sea level rise in this century. There are three scenarios, with temperature increases over Greenland by 2130 of 3.2°, 5.8° and 8.4° C, respectively. The scenario with the highest temperature rise corresponds roughly to the most C-intensive IPCC scenario (A1FI). The actual rate of increase in CO2 concentrations by now is actually a little higher than this worst IPCC scenario (links here and here), that is, if present trends continue, the situation will correspond to more than an 8.4° C temperature increase over Greenland, which will yield the 20 cm extra sea level rise referred to above. However, the paper states (p. 1020) that the climate computer model used falls toward the low end of sensitivities. So in reality the rise could possibly be even larger.

FLAW:
Page 81 bottom and note 415: "On Figure 21 that would be 40 times higher than the absolutely highest model estimate . . . "
Flaw: Note 415 has 7 m rise per century, whereas Hansen talks about 5 m rise per century as the highest that has occurred in the Earth´s known history. The curves in Figure 21 do certainly not include the absolute highest estimates, because they do not include runs on scenario A1FI, and they do not include the extra melt due to dynamical glacier response, which Lomborg is aware of. So the figure of 40 times has been deliberately inflated in several ways.

FLAW:
Page 82, Figure 22: "The estimate of Al Gore/Hansen  . . . "
Flaw: It is not true that Al Gore/Hansen estimate or expect a rise of 609 cm. Hansen says that the fastest known rise that has occurred in the Earth´s prehistory is 5 m in a hundred years; but he does not predict or ecpect that precisely that will happen. The range of 1 cm to 15 cm, taken from Figure 21, excludes the effect of dynamic response of glaciers. According to IPCC 2007, WGI, paragraph 10.6.5., the dynamic response may probably add another 10-20 cm to the output from static models. 

FLAW:
Page 83 top: ". . . but maximally contribute 55 cm in the following centuries and decline thereafter . . ."
Flaw: The text is written so that it is invariably misunderstood. The reader will understand that instead of Al Gore´s 20 feet, melting of Greenland ice will maximally contribute 55 cm to sea level rise in total. But what was meant is that the contribution will be 55 cm in each century, each contribution being added to the previous one, and that later on each new century will see a contribution of somewhat less than 55 cm.

(COMMENT)
Page 83 bottom: " . . . the warmest year in Greenland was 1941. . . "
Comment:
    In response to this, John Cappelen, meteorologist at the Danish Meteorological Institutet, DMI, says that the truth is more complicated, because Greenland is large, and the trends are not the same at the seven stations where temperatures have been followed. He also says that at the east coast, 2003 is the warmest year on record, whereas at Nuuk (the "capital", situated in south west Greenland), 1941 and 2003 were equally warm. j
     The temperatures for three weather stations at the west coast of Greenland are to be found on the internet here. The average for Nuuk was +0.83° in 1941, and +0.51° in 2003, i.e. slightly lower. Also this link gives a survey of record temperatures, indicating that on the east coast, but not the west coast, 2003 was the warmest year on record. So Lomborg is right as to the west coast of Greenland, but not as to Greenland in total.
   It may be added that the extent of ice melting on Greenland is steadily increasing, see here. Remember that melting consumes heat energy and tends to lower temperatures. If you put a clump of ice in a jar and supply a heat source to melt the ice slowly, the temperature in the jar will remain constant - at exactly 0° C - as long as there is still ice left in the jar. It is only when all ice has melted that water temperatures start to rise. So if there is a lack of local temperature rise, this cannot be used as an argument that there is no increase in ice melting.
   The temperature trends for Greenland are not typical for the whole arctic region, as is evident in Przybylak (2000), cited by Lomborg.

ERROR
Page 83, Figure 23
Error: The curve does not agree with the data source. It seems that there is an error in the scale on the vertical axis. This original source is found at this link.
 


 TEMPERATURES ON ANTARCTICA

ERROR
Page 84: "Al Gore focuses exclusively on this 4% of Antarctica."
Error:
This is not true. In the film, he also focuses on the Ross ice shelf. In the book, he furthermore focuses on East Antarctica.

ERROR
Page 84: "The vast part of Antarctica has cooled."
Error:
Lomborg writes that the only part of Antarctica that is warming is the west Antarctic peninsula which makes out only 4  % of the total land area; the remaining 96 % has become colder. But this is not true.
    Temperatures for those Antarctic weather stations with the longest time series are found at this link. It is seen here that since the mid 20th century, annual temperatures have increased significantly at the west Antarctic Peninsula and in one coastal station on mainland Antarctica. At all other weather stations, including the South Pole, there is no significant trend. In a few stations there is a significant negative trend for autumn temperatures, but not for annual temperaturs.
    The information that 96 % of the Antarctic continent is cooling goes back to a paper by Peter Doran et al. in 2002 in Nature (link). They found (by a different type of analysis) that 58 % of Antarctica had cooled from 1966 to 2000, especially regarding autumn temperatures, whereas the rest, i.e. 42 %, had warmed, including the west Antarctic peninsula that makes out 15 % of the area.
   The cooling of parts of the continent is partially due to the ozone hole. According to Doran, as the ozone hole heals - thanks to worldwide bans on ozone-destroying chemicals - all of Antarctica is likely to warm with the rest of the planet.
    The summary of the paper in Nature pointed out how the cooling trend posed challenges to models of Antarctic climate. American newspaper and television reports focused on this part of the paper, and claimed that these scientific findings ran counter to the theory of global warming. Since then, climate skeptics have cited this information over and over again. Although the scientists have written rebuttals and explained that the media have misunderstood the information, the misinsterpretation has quickly become legend among skeptics, and is cited ever more often. A refutation written by Peter Doran in The New York Times may be read here. It is unacceptable that Cool it writes something which is denied by the leading author of the source paper. Therefore, this is a case of deliberate misleading either by Lomborg himself or by his possible secondary sources.

ERROR
Page 84, figure 24.
Error:
As explained above, this figure is not correct. There has been no significant decline in annual temperatures anywhere on Antarctica during the indicated period.

FLAW
Page 85 top: " The significance of this break-up relies on us believing that Larsen-B has been intact from time immemorial. . .  . . "
Flaw:
The Larsen-B ice shelf has existed without interruption since the ice age (Domack et al. 2005, Curry & Pudsey 2007), and its breakup is ascribed to man-made global warming (Marshall et al 2006). Also the IPCC report (4AR wg1 paragraph 4.6.3.4) says: " . . the ice shelf changes have resulted from environmental warming . . "" Before the 2002 breakup of the Larsen B Ice Shelf, local air temperatures had increased by more than 1.5°C over the previous 50 years .. increasing . . formation of large melt ponds on the ice shelf. These likely contributed to breakup . . ".

FLAW
Page 85: "While it probably led to ice shelves floating more quickly . . . "
Flaw: This is an understatement. After the collapse of the Larsen B ice shelf, the movement of inland glaciers behind the ice shelf accelerated by a factor of 2 to 8 (Rignot et al (2004): Geophys res. lett. 31(18): L18401; Scambos et al. (2004): Geophys res. lett. 31(18): L18401; Rignot (2006): Phil- trans. Royal Soc. A 364: 1637-1655.)


ERROR
Page 85 and note 438: "Precipitation on the Antarctic Peninsula is large and increasing . . . and this likely outweighs the melting "
Error: Lomborg´s use of the references is very selective here. For instance he cites Zwally et al. (2005) in which there is a single station on the peninsula showing net accumulation of ice, whereas the same study shows that West Antarctica in total has a large net loss of ice. Morris and Mulvaney (2004) indicate a net increase of ice on the peninsula with future warming (which gives more precipitation), and state that for each degree of warming, the effect on global sea level will be ÷ 0.006 mm. However, warming will also increase the discharge of glacier ice by ablation, that is melting, sublimation and calving, and for each degree of temperature rise, this will contribute + 0.07 mm to global sea level, provided that meltwater can find its way into the sea. Thus, the net effect of melting may be much greater than the net effect of snow accumulation. Although Lomborg touches on this aspectin his note, he avoids the crucial circumstance that precipitation will probably not outweigh melting. This is deliberate distortion of the information he has read. 

FLAW:
Page 85: " . . . the Antarctic Peninsula is probably causing an overall lowering of sea levels."
Flaw: There are indications to the opposite. Firstly, Morris & Mulvaney (2004) indicate that the removal of ice by various processes, especially melting,  may possibly outweigh snow accumulation in the future. This was explained above. In addition, however, there is an effect of accelerating glaciers. Because glaciers are thinning at their ends, they are now moving faster towards the sea than before. This is described in Pritchard & Vaughan (2007): Journal of geophysical research 112 F03S29. They estimate that the net contribution of the Antarctic Peninsula to global sea level from this glacier acceleration and other processes is + 0.16 mm per year. Also van de Berg et al. (2006): Journal of geophysical research 111 D1104 find that the mass balance of the peninsula is probably negative. This is directly opposite what Lomborg states.

GROUNDLESS DEROGATION
Page 85: "That is, despite the spectacular pictures that Al Gore can show us of Larsen-B . . . "
Error: As is evident from the other comments given here, Lomborg is completely wrong on all aspects of the issue, and his derogation of Al Gore here is therefore also completely unjust.

ERROR
Page 85: "This, of course, is the story of the much bigger continent writ large."
Error: No, it is not. For instance, Lomborg has cited Zwally et al. (2005) as a source for accumulation of ice and snow on the peninsula. But in the same source there is a total estimate of mass gain or loss on Antarctica. There is an estimated total loss of 47 gigaton ice on the whole of west Antarctica, which is not fully conuterbalanced by an estimated gain of 16 giga ton on east Antarctica. This gives a net loss of 31 giga tons per year, which contributes to sea level increase, not decrease. When Lomborg has read this, but nevertheless says the opposite, he is deliberately misleading. Many other references likewise indicate a net loss of ice on the Antarctic continent.

ERROR
Page 85: " . . . a decrease in sea levels in all models. "
Error: This is contrary to the contents of the 2007 IPCC report WG 1, according to which Antarctica gives a net positive contribution to sea level rise. not include dynamical responses of glaciers. It says in the first paragraph: "Such accelerated flow leads to increased ice discharge into the ocean, but the relevant dynamical processes are not properly understood nor included . . . This therefore represents an important uncertainty for predictions of sea level, but one which is beyond the scope of this paper to address." So the Gregory & Huybrechts paper does not deal with all contributions to sea level rise. Actually, the present state of knowledge (2010), as stated in the papers cited on top of this page, is that Greenland as well as Antarctica give a net contribution to sea level rise. ERROR
Page 85 before bottom: " . . . all models predict ever more net accumulation over this century. "
Error: This is contrary to the trends right now, when there is probably an increasing net contribution to sea level rise (see for instance Allison et al. 2009, cited at the start of this page).  Lomborg does not indicate which models he is talking about, so it is impossible to check his source.

FLAW OF OMISSION:
Pages 84-85: Flaw: Elsewhere, whenever it fits into Lomborg´s agenda, he is keen to write about future trends, often writing as if future scenarios were known facts. However, concerning temperatures on Antarctica, he omits doing that. The paper by Chapman and Walsh, which he has read, projects a steadily increasing air temperature during the next decades over all parts of the Antarctic continent. This is probably a deliberate bias.


(COMMENT)
Page 86: "PENGUINS IN DANGER?"
Comment: Lomborg criticises the way that the decline of a population of emperor penguins is presented in Al Gore´s  book "An Inconvenient  Truth". However, as explained on the Lomborg-errors page on Al Gore, for page 178 in Gore´s book, there is very little flaw in Al Gore´s text. On the basis of data from G.L. Kooyman, Lomborg infers that there may have been increases in certain emperor penguin populations on the Ross ice shelf; however, a new paper co-authored by Kooyman statesthat the colonies referred to have had no significant changes up to now, except that one out of six colonies (one not referred to by Lomborg) has had a small increase. Also, new information from 2009 says that the studied colony of emperor penguins is expected to decline very much during this century because fo changes in sea ice (Jenouvrier & Caswell (2009): Proceedings national academy of sciences USA 106(6): 1844-1847).


ERROR
Page 86: "Moreover, the other main Antarctic penguin, the Adélie . . . not telling the full story. "
Error: The full story about the Adélie penguin is that populations decline in some places and increase in other places (link). Lomborg refers to a report from a place in east Antarctica where the species is on the increase. Lomborg has also read a short paper by Vaughan (2001) which has the following text: "Adélie penguins, which require access to winter pack ice, are declining around Faraday, whereas chinstrap penguins, which usually require open water, are increasing. The rookeries vacated by the Adélie penguins seem to have been occupied continuously for ~644 years, and there is no evidence that chinstrap penguins were present more than 20 to 50 years ago." So, when Lomborg sees two papers on Adélie penguin populations, one declining and one increasing, he mentions only the one that is increasing. Clearly, populations at the Antarctic Peninsula are shifting as a result of global warming (more open water). Considering that Lomborg criticizes those that do not tell the full story in the same sentence where he himself does not tell the full story, this is counted as an error.

(COMMENT)
Page 86: ". . . underscoring the problem in simply blaming global warming and not telling the full story."
Comment:This is not a fair criticism of Al Gore. First, Al Gore says that it is uncertain if global warming is the cause of the decline. Second, the trends in Adélie penguin populations are mixed - there is a trend for a general shift towards the south (i.e. polewards), concomitant with rising sea surface temperatures. This means that the southernmost colonies of Adélie penguins are increasing, whereas the northernmost populations are decreasing. Lomborg fails to mention this, so he, too, does not tell the full story.