Foreword by the blog moderator:
One of the things that often happens once your blog and effort is well known is that people start sending you things to look at and/or do. That’s the case here. There has been much discussion web-wide over AIT and potential inaccuracies in the presentation by Gore, but I have not taken on the subject here in any detail since I have my http://www.surfacestations.org/ USHCN weather station census requiring a good portion of my time. Nonetheless, when I was offered this review, it seemed to be quite comprehensive in scope, and done by a person who worked in aeronautic systems engineering, a very detail oriented job that combines many disciplines. He had a thirty-three year career at Boeing, beginning as a software engineer in data reduction and flight simulation and retiring as the Chief Engineer of the Electronic Systems Division.
While AIT has been reviewed by many, I thought this review had some interesting points. Therefore, as a catalyst for discussion, here is Bob’s review of AIT with no editing nor commentary on my part.
UPDATE 10/5/07 A few commenters pointed out that there was a mistake that needed correcting. Mr. Edleman requested I repost his newly edited version that corrects a mistake in attribution of the institution Dr. Phil Jones is tenured at. Some additional format changes were made for readability by Mr. Edelman.
by Bob Edelman
October 3, 2007
My sister viewed Al Gore’s movie, An Inconvenient Truth, and was disturbed enough to ask my opinion. In her words, “if the story is mostly true, we’d better stop the ideological wrangling and get busy salvaging what we can”. After some prodding I reluctantly rented the DVD and prepared the following comments in response. My conclusion is that the movie is mostly misleading and, yes, we’d better stop the ideological wrangling and consider the facts.
Comments on An Inconvenient Truth
Most of my comments pertain to the climatology science presented in the movie although I do include a discussion of charges made by NASA’s James Hansen that his scientific findings have been suppressed. I also discuss the issue of scientific consensus. I gave a pass to most of the trivial errors although I couldn’t help pointing out some that jumped out at me. Please forgive the nit-picking. A few words about the general circulation models (GCMs) used to predict climate change. Al Gore didn’t explicitly discuss the models that he used or the accuracy of his predictions so I don’t discuss them in my comments. Yet whenever he discusses future climate he necessarily is either guessing or relying on someone’s GCM. Given that no model has ever been validated I believe that the state-of-the-art still has a long way to go before climatologists can make predictions good enough to drive policy. One glaring hole in climate models is adequate modeling of precipitation systems. They are not modeled well because they are not understood. Yet precipitation systems are extremely important to moderating climate. A recently published study of tropical precipitation systems by Dr. Roy Spencer supports the existence of a strong negative feedback to temperature increases rather then the assumed positive feedback now modeled in GCMs. Once such systems are understood and modeled properly we may find why the earth’s climate is not as fragile as some would have us believe. After all, the earth once had an atmosphere consisting of mostly greenhouse gasses (carbon dioxide, methane and water vapor) and nitrogen, yet life and the climate evolved. The following comments are organized in the same chronology as the film. I suggest that you view An Inconvenient Truth on DVD and follow along since it is difficult to insert Gore’s slides into my comments. The most significant comments are in bold.
1. The story about his sixth grade teacher may or may not be true – she may have been reflecting her own sixth grade education. The point of his story, however, was fabricated. He ends the story by saying that “the teacher was actually reflecting the conclusion of the scientific establishment at that time: Continents are so big that obviously they don’t move.” When Gore was in the sixth grade (about 1960) the scientific community had generally accepted the concept of continental drift.
2. Gore’s explanation of the greenhouse effect is grossly over-simplified. The sun’s radiation reaches the earth in a broad spectrum, not just “light”. The warm earth emits long infrared radiation. Some of that radiation is absorbed by greenhouse gasses, the most significant of which is water vapor followed by CO2. The energy is re-radiated at wave lengths that differ from the excitation radiation. Most of the re-radiated energy is lost to space but some reaches the earth where it contributes to keeping the atmosphere at a comfortable temperature. The radiation is not “trapped”.
3. In his explanation of the greenhouse effect he incorrectly equates it to global warming. This helps create the perception that people who disagree with his conclusions deny the existence of global warming and/or the greenhouse effect. Actually, there is general agreement on the following:
- There is a greenhouse effect. It makes our planet livable.
- CO2 is a greenhouse gas. There is disagreement as to its significance since water vapor is, by far, the most important.
- There was global warming on the order of about 1ºF during the twentieth century. There is disagreement as to its cause.
4. The assertion that his professor, Roger Revelle, was the first person to have the idea to measure the amount of CO2 in the earth’s atmosphere is false. Scientists have been measuring atmospheric CO2 since well before Revelle was born and the measurements showing increased concentrations were reported 20 years before Revelle’s study. Also, Gore implies that Revelle was concerned about the global warming effects of increased CO2 emissions. He wasn’t. In fact, Revelle is on record saying that increased CO2 could be beneficial and that it is too early (in 1991) for drastic action to prevent global warming effects.
5. The assertion that the ice cap on Mount Kilimanjaro is disappearing because of global warming is not correct. It is generally accepted that the cause is desiccation of the atmosphere that resulted from deforestation. The temperature at the ice cap has remained at about minus 7ºC, indicating that ice cap loss has been from ablation (sublimation) to the dry atmosphere, not melting.
6. The use of Glacier National Park as an example of man-caused (anthropogenic) global warming is wrong. Those glaciers have been receding since the beginning of record keeping. In fact, the rate of retreat was greater 75 years ago then now.
7. The idea that the world’s glaciers are disappearing because of CO2 stretches credibility. Remember, the 20th century increase in temperature has been about 1ºF, much of which occurred before the era of large CO2 emissions. Most glaciers in temperate climates are relics of the ice age and have been receding since that time. Nevertheless, a large number of glaciers are growing, none of which were shown in the film, and only a small percentage of glaciers have been studied for mass balance changes out of the 67,000 that have been inventoried. (Note: the rate of recession and the rate of mass loss are two different things.)
8. Gore shows a glacier calving to illustrate the horrors of global warming. “Here is what has been happening year by year to the Columbia Glacier. It just retreats more and more every year. And it is a shame because these glaciers are so beautiful. People who go up to see them, here is what they are seeing every day now.” Gore doesn’t seem to recognize that glacier ice slowly flows down-hill and calving is quite normal. A growing ice-cap will also calve.
9. The assertion that people in the Himalayas will lose their drinking water because of glacier melting in the next 40 years may be true, but not because of anthropogenic global warming. The Gangotri glacier has been receding as have most relics of the ice age. However, it is incorrect to blame it on recent global warming. Melting occurs in the summer and temperature records since 1875 show a history of decreasing summer temperatures. This illustrates the major problem with using glaciers to prove catastrophic anthropogenic global warming.
10. Gore attributes the retreat of a Peruvian glacier to global warming without mentioning the fact that the region has been cooling since the 1930’s. He also fails to mention the other South America glaciers that have been growing.
11. Gore makes these comments when showing a video of an ice-core sample: “When I was in Antarctica I saw cores like this and the guy looked at it. He said right here is where the US Congress passed the Clean Air Act. I couldn’t believe it but you can see the difference with the naked eye. Just a couple of years after that law was passed, it’s very clearly distinguishable.” I will give Gore the benefit of the doubt and say that he was the victim of a joke.
12. Gore incorrectly shows the infamous “hockey stick” chart as temperature history from ice-core data. This was actually from a study published by Dr. Michael Mann in 1999. He used tree ring data as a proxy for temperature for data up to the 20th century and then tacked on thermometer data. The graph shows a slow decline in global temperature for 1,000 years (the shaft of the hockey stick) and then a sudden increase in the 20th century (the blade of the hockey stick). The study was quickly accepted by global warming alarmists without adequate review because it wiped out the pesky Medieval Warm Period (MWP) and the Little Ice Age. Some scientists raised a number of questions about the lack of agreement with previous studies and the historical record. Two Canadians, McIntyre and McKitrick, attempted to examine the methodology and, after much difficulty in acquiring data and software algorithms, were able to show gross errors in the use of statistical techniques. This controversy culminated in two studies requested by congress. The first was by the National Research Council (at the NRC’s suggestion) which gave some credence to Mann’s study although limiting it to 400 years. No statisticians were on the committee and, it turns out, most of the committee had professional connections to Dr Mann. A second independent study by a team of mathematicians was requested and headed by Dr. Edward J. Wegman. The Wegman study thoroughly discredited the Mann study because of invalid use of statistical techniques and found that the conclusions by Mann could not be supported. However, some still cling to the hockey stick. Gore is apparently one of them.
13. Gore uses the discredited hockey stick to downplay the MWP and deride scientists who have shown the importance of climate change cycles. There have been numerous studies before and after the Mann study that show, through other proxies, the global extent of and magnitude of the MWP. There is ample evidence that the planet was warmer during the MWP then it is now. There are also numerous studies that show the existence of various cycles, such as the earth’s orbital cycles, and how those cycles can affect major climate changes.
14. When Gore does display the ice-core data he incorrectly uses it to assert that CO2 is directly responsible for global temperature change. This is the most egregious error in the movie.
“Now an important point: In all of this time, 650,000 years, the CO2 level has never gone above 300 parts per million. Now, as I said, they can also measure temperature. Here is what the temperature has been on our earth. One thing that kind of jumps out at you is… Let me put it this way. If my class mate from the sixth grade that talked about Africa and South America might have said, “Did they ever fit together?” Most ridiculous thing I ever heard. But they did of course. The relationship is very complicated. But there is one relationship that is more powerful than all the others and it is this. When there is more carbon dioxide, the temperature gets warmer, because it traps more heat from the sun inside.“
All technical studies of ice-cores show the same thing; CO2 increases follow temperature increases and CO2 decreases follow temperature decreases. In other words, ice-core data show that temperature changes drive CO2 changes to a very large extent. The actual amount of the lag varies from different studies but it is approximately 800 years. The reason for the lag is postulated to be the delayed release and absorption of CO2 from the oceans, the earth’s largest reservoir of carbon. The reason for the large delay is the huge depth of the oceans and the time that it takes a temperature change to propagate. Gore and his technical advisors are certainly well aware of these facts.
15. The ice-core graph along with estimates of CO2 growth is used to give the impression that the concentration of CO2 in the atmosphere is greater than ever before in history and that it is going “off the chart”. In truth, CO2 concentrations have been much higher in geologic history. During the Cambrian Period (543 to 490 million years ago), concentrations were as high as 18 times the present level. It was during this period that there was an explosion of diverse life on earth (called the Cambrian explosion) and almost all living animal groups appeared. At the end of the Ordovician Period (490 to 443 million years ago) the earth experienced an Ice Age, yet CO2 concentrations were almost 12 times the present level. CO2 concentrations were almost 5 times higher during the Jurassic Period (206 to 144 million years ago), yet life thrived. These facts are at odds with the assertion a doubling of CO2 in the atmosphere will be catastrophic to life.
16. Gore’s claim that there is no controversy over the amount of CO2 growth in the next 50 years is wrong.
17. Gore shows a chart purporting to be actual temperatures since the Civil War. (Note that the film doesn’t expose the dependent axis. If he did it would emphasize how small the changes in temperature were.) Gore states:
“These are actual measurements of atmospheric temperature since our civil war. In any given year it might look like it’s going down, but the overall trend is extremely clear. In recent years it is uninterrupted and it is intensifying. In fact, if you look at the 10 hottest years ever measured in this atmospheric record, they have all occurred in the last 14 years. The hottest of all was 2005.“
He can be forgiven for having been misled by a close advisor, Dr. James Hansen who heads the Goddard Institute for Space Studies (GISS). Hansen has recently been forced to admit that errors were made in correcting raw data and that the hottest year was 1934. Here is the new ranking: 1934, 1998, 1921, 2006, 1931, 1999, 1953, 1990, 1938, 1939.
This change in ranking came about because of the efforts of non-professionals. GISS derives temperature from a large network of stations in the United States. They have been severely criticized for using stations that are poorly placed so that significant error is introduced by artificially induced local heating and urbanization. GISS filters the data to extract very low temperature change signals from the very large temperature noise. A former TV meteorologist, Anthony Watts, voluntarily maintains a web site where individuals have been recruited to examine stations in a systematic manner and post photographs and station characteristics. To date, records for about 33% of the stations in the US Historical Climatology Network have been surveyed. There are numerous examples of poor placement such as near heat exchangers, on or near concrete, exposure to jet airplane exhaust, and even exposure to a burn barrel. The record of one station located near two air conditioner exhausts showed a sudden increase in temperature readings when the air conditioners were installed. It was noted, however, that the discontinuity continued in the winter when the air conditioners were presumed to be off. This got the attention of Steven McIntyre, the same Canadian who discovered the hockey stick math problems. He attempted to get the data reduction algorithms from Hansen but was refused access. (Refusing review of one’s work is not how responsible scientists behave.) McIntyre was forced to reverse engineer data from a number of stations and found a “Y2K” problem, i.e., discrepancies were introduced in the year 2000. Hansen has now admitted that he made errors when transitioning to a different data set but still refuses to divulge his methods. (I have more to say about Hansen later.)
18. The connection of heat waves to global warming is grossly exaggerated. Remember, the 20th century increase in temperature has been about 1ºF.
19. Gore claims that the oceans have warmed (by about .2 degrees according to his chart). Harison and Carson of the University of Washington studied 50 years of data from 1950 to 2000 and concluded that there was no warming evident. (Their data actually show cooling from 1980 to 1999.) They concluded that “The ocean neither cooled nor warmed systematically over the large parts of the ocean for the entire analysis period.”
20. Gore claims that increased hurricane activity is caused by global warming. This claim is not supported by empirical studies. In fact, a recent study of tropical cyclones in Australia from 1226 to 2003 showed a decrease in the frequency and intensity of hurricanes in the last 100 years. (It is interesting how the researchers got records that old. They found that a heavy isotope of oxygen, O-18, is deficient in precipitation from cyclones. They measured the deficiency of O-18 deposited in stalagmite layers as a proxy for cyclone intensity and then validated their method against records of modern cyclones.)
21. The claim that Lake Chad drying is caused by global warming is not correct. NASA concluded that water use and grazing are the probable causes.
22. Gore shows a dramatic photo of a crack in the Ward Hunt Ice Shelf to illustrate “faster impacts from global warming” in the Artic and says that “scientists were astonished”. Some may have been surprised but scientists who have studied the ice shelf point out that it is a remnant of a larger feature that has been contracting since the end of the Little Ice Age and had already lost 90% during the period 1906-1982 due to calving.
23. Gore shows a photo of a house that was built on permafrost and sunk when the permafrost melted. Solution: Don’t build a house on permafrost unless you plan to keep the living areas below freezing. (Alaskans figured this one out a long time ago.)
24. A chart that purports to show that “there was a precipitous drop off in the amount and extent and thickness of the arctic ice cap” starting in 1970 is questionable. It has been reported that the data points were not all taken at the same time of the year. Also, 1970 was the end of a 25 year cooling period. Dr. Dick Morgan, a climatology researcher at the University of Exeter wrote: “There has been some decrease in ice thickness in the Canadian Arctic over the past 30 years but no melt down. The Canadian Ice Service records show that from 1971-1981 there was average, to above average, ice thickness. From 1981-1982 there was a sharp decrease of 15% but there was a quick recovery to average, to slightly above average, values from 1983-1995. A sharp drop of 30% occurred again 1996-1998 and since then there has been a steady increase to reach near normal conditions since 2001.”
25. The animation of the desperate polar bear is representative of nothing. Polar bear population is increasing or stable in all areas except where there has been cooling! As a species they have survived much warmer temperatures seen 6000 years ago.
26. Gore does a good job of describing the thermohaline pump and how the pump was shut down when a huge lake of fresh water was suddenly dumped into the ocean at the end of the ice age. However, he seems to imply that slow melting of the icecap will produce the same effect. This is not correct and no scientist worth his halide would make that claim.
27. The claims that global warming is causing “exotic” species to appear where they were never seen before and outbreaks of disease have little or no basis. For example:
- “You’ve heard of the pine beetle problem? Those pine beetles used to be killed by the cold winter, but there are fewer days of frost. So the pine trees are being devastated.” Actually the pine beetle is native to areas where large outbreaks occurred. Small outbreaks became large because of forest management problems.
- “There are cities that were founded because they were just above the mosquito line. Nairobi is one. Harare is another. There are plenty of others. Now the mosquitoes with warming are climbing to hirer altitudes.” This is nonsense. These cities have always had mosquitoes and malaria. Malaria was a world-wide disease, including the United States at one time.
- “The Avian flu, of course is quite a serious matter, as you know. West Nile Virus came to the eastern shore of Maryland in 1999. Two years later it was across the Mississippi. And two years after that it had spread across the continent.” More nonsense. Avian flu (or any other kind) is not associated with higher temperatures. West Nile Virus is a mosquito-borne virus that came from Israel. According to the CDC, the virus was never confined to tropical areas. The fact that these diseases spread to temperate areas contradicts Gore’s claim that they spread because of global warming.
28. Gore’s discussion of the Antarctic focuses on the dramatic break up of the Larsen B ice-shelf in Western Antarctica. Andrew Monaghan of Ohio State University’s Byrd Polar Research Center and 15 colleagues have been studying the thickness of the ice cap. They point to evidence that the West Antarctic Ice Sheet has been thinning over the past decade, while the East Antarctic Ice Sheet has thickened. A lot of work needs to be done to explain just what is happening in the Antarctic and concentrating on one single event can give a very distorted picture.
29. Gore makes another absurd claim that Pacific islanders were forced to evacuate to New Zealand when part of the Antarctic ice shelf broke off. Dr Chris de Freitas, a climate scientist from the University of Auckland stated: “I can assure Mr. Gore that no one from the South Pacific islands has fled to New Zealand because of rising seas. In fact, if Gore consults the data, he will see it shows sea level falling in some parts of the Pacific.”
30. Gore postulates a 20 foot rise in sea level if the Greenland ice cap or the Antarctic ice cap melted. He then shows the devastation that would occur from such a chance in sea level. No reputable scientist is predicting such a huge magnitude rise in sea level. Even the global warming alarmists on the UN’s Intergovernmental Panel on Climate Change (IPCC) have projected a range of only 18-59cm at the end of this century based on various models and scenarios.
31. The map showing that the US contributed 30% to global warming is actually a map produced by the World Resource Institute that purports to show CO2 emissions resulting from fossil fuel combustion. Global warming and fossil fuel consumption are not the same thing. Nor are global warming and CO2 emissions the same thing. Even if they were the map doesn’t show other sources of CO2 such as the 30% that Gore claims comes from burning wood.
32. Gore says:
“There was a massive study of every scientific article in a peer reviewed article written on global warming in the last ten years. They took a big sample of 10 percent, 928 articles. And you know the number of those that disagreed with the scientific consensus that we’re causing global warming and that is a serious problem out of the 928: Zero.“
Anyone familiar with the scientific literature knows better. The study that he is referring to was conducted by social scientist Dr. Naomi Oreske. Another social scientist, Dr. Benny Peiser of the UK, attempted to verify Oreske’s study. The following is his summary:
“I replicated her study in order to assess the accuracy of its results. All abstracts listed on the ISI databank for 1993 to 2003 using the same keywords (‘global climate change’) were assessed. The results of my analysis contradict Oreskes’ findings and essentially falsify her study: Of all 1117 abstracts, only 13 (1%) explicitly endorse the ‘consensus view’. However, 34 abstracts reject or question the view that human activities are the main driving force of ‘the observed warming over the last 50 years’.
Oreskes claims that ‘none of these papers argued [that current climate change is natural]’. However, 44 papers emphasise that natural factors play a major if not the key role in recent climate change.
The most significant discrepancy with Oreskes’ results concern abstracts that are undecided whether human activities are the dominant driving force of recent warming. My analysis shows that a significant number of abstracts reject what Oreskes calls the ‘consensus view’. In fact, there are almost three times as many abstracts that are unconvinced of the notion of anthropogenic climate change than those that explicitly endorse it.”
Two German environmental scientist, Dennis Bray and Hans von Storch, conducted an extensive survey of 530 climate scientists from 27 different countries in 2003. (A similar survey was conducted in 1996.) On the critical assertion, “human activity is causing climate change” only 55.8% agreed, 30% disagreed, and the rest were uncertain. This is hardly unanimous agreement.
In a recent analysis of peer-reviewed studies, Dennis Avery and Fred Singer listed more than 500 climate scientists whose studies confirmed that climate change is a natural phenomenon.
There is no consensus. Even if there were it would have no value in science. Proof leads to consensus, not the other way around.
33. Gore claims: “The misconception that there is disagreement about the science has been deliberately created by a relatively small number of people. One of their internal memos leaked and here is what it said according to the press. Their objective is to reposition global warming as a theory rather than fact.” I know of no efforts to “reposition global warming as a theory”. All reputable scientists recognize that there has been warming since the little ice age. However, “anthropogenic global warming leading to disastrous results” is properly positioned as theory.
34. The movie shows testimony before the Senate from 1989 where James Hanson reveals that the final paragraph in his testimony was written by OMB during its review. The movie leaves the impression that scientific findings were changed. What actually happened is this: OMB added a sentence that Hansen’s conclusions “should be viewed as estimates from evolving computer models and not as reliable predictions.” Hansen phoned Gore and requested that he ask about the changes during the hearing. As it turns out, Hansen’s predictions were not reliable and his faith in them was not scientifically based.
Hansen openly admits to ignoring NASA media policies and frequently has made accusations of political interference since 1988. Recently, the Washington Post reported:
“The debate has been intensifying because Earth is warming much faster than some researchers had predicted. James E. Hansen, who directs NASA’s Goddard Institute of Space Studies, last week confirmed that 2005 was the warmest year on record, surpassing 1998. Earth’s average temperature has risen nearly 1 degree Fahrenheit over the past 30 years, he noted, and another increase of about 4 degrees over the next century would ‘imply changes that constitute practically a different planet.’
‘It’s not something you can adapt to,’ Hansen said in an interview. ‘We can’t let it go on another 10 years like this. We’ve got to do something.’
This tipping point debate has stirred controversy within the administration; Hansen said senior political appointees are trying to block him from sharing his views publicly.
When Hansen posted data on the Internet in the fall suggesting that 2005 could be the warmest year on record, NASA officials ordered Hansen to withdraw the information because he had not had it screened by the administration in advance, according to a Goddard scientist who spoke on the condition of anonymity. More recently, NASA officials tried to discourage a reporter from interviewing Hansen for this article and later insisted he could speak on the record only if an agency spokeswoman listened in on the conversation.
‘They’re trying to control what’s getting out to the public,’ Hansen said, adding that many of his colleagues are afraid to talk about the issue. ‘They’re not willing to say much, because they’ve been pressured and they’re afraid they’ll get into trouble.'”
Again, Hansen turned out to be wrong and has had to revise his data. (See previous discussion about hottest years.) He now downplays its importance and blatantly lies about past practices. The following is from a recent article in the New York Times:
“Dr. Hansen and his team note that they rarely, if ever, discuss individual years, particularly regional findings like those for the United States (the lower 48 are only 2 percent of the planet’s surface). ‘In general I think that we want to avoid going into more and more detail about ranking of individual years,’ he said in an e-mail message. ‘As far as I remember, we have always discouraged that as being somewhat nonsensical.'”
Hansen has made a number of other incorrect predictions but he continues to hype the dangers of anthropogenic global warming. If past and present administrations have been attempting to suppress Hansen they have been spectacularly ineffective. Google his name and you will see what I mean.