Al Gore´s film, "An Inconvenient Truth" is having a tremendous public impact. It is part of an education pack that has been sent to all secondary state schools in UK; it has won an Oscar; and Al Gore has received the Nobel Peace Prize.  The companion book, with the same title as the film, has reached a #1 position on the New York Times bestseller list for paperback nonfiction.
    With such an impact, it is no wonder that climate skeptics have made great efforts to undermine the message of the film. This is done by pointing out scientific or factual errors, or what is postulated to be errors. The claim could be either that Al Gore has a fundamentally wrong presentation of central issues, or that the number of errors is so large that the film cannot be trusted. To cite one of the critics, Marlo Lewis of the Competitive Enterprise Institute: "By the sheer number of errors and distortions I have uncovered, I hope to foster a healthy skepticism about global warming alarmism and the energy suppression agenda it allegedly justifies."
    In a case at a UK high court in 2007 a judgment was made that certain claims in the film were somewhat misleading and required an amended guidance note before the film could be distributed to British school classes. I give more details on this case here.
    In Bjørn Lomborg´s book, "Cool it!", a main theme is criticism of Al Gore´s film and book. Besides that, there are several other extensive attacks on the film and book; a number of "error lists" are to be found on the internet. Some of the critics, like Lewis from CEI referred to above, have obvious political motives for their criticism, even if the criticism itself has a factual or scientific character. On the other hand, Al Gore´s film obviously also has political motives, even if it is based on facts and science. So Gore and his critics stand even in that respect. There is no a priori reason that either part should not be right, irrespectively of their political motives, so all claims and counter-claims should be carefully investigated.
 

In the light of all this, it seems timely to make an overview of how many errors are actually found in Al Gore´s film, and how does the number of such errors compare with the number of errors in Lomborg´s books, judging by the same standards.

I have therefore carefully investigated a number of so-called error lists, which in total include more than 100 alleged errors and distortions in Al Gore´s film. These lists are presented on this page. I have tried to judge each alleged distortion by the same standards as I have used in relation to Lomborg. I have tried to be at least as hard with Al Gore as I have been with Lomborg, in order that the comparison could be fair. My judgments have not always led to the same result as those made in the case at the British high court. That case was about whether the film was suitable for children in secondary schools. This implies criteria that may differ from those used to evaluate Lonmborg´s books, which are presumably read nearly exclusively by adults. So the criteria are whether adult readers would be misled, and whether the claims are formally correct. When Lomborg makes claims that are formally correct, but nevertheless misleading (for instance statements that stand only "between the lines"), these are not counted here as errors, unless they give an unequivocal impression of something untrue.
 

The results are on this page, which presents those errors or flaws in "An Inconvenient Truth" that I have judged to be real. In addition, the list contains a number of points that require a clarifying discussion, but which are not errors. These are marked (Comment) and, just like in the lists concerning Lomborg, they are not counted as errors.

A count of the errors gives the following result:
Al Gore´s film: 2 errors, 8 flaws, 10 in total.
Al Gore´s book: 2 errors, 11 flaws, 13 in total.
Film and book together: 2 errors, 12 flaws, 14 in total.

This may be compared with the situation in Lomborg´s books. Up to now (11/1. 2011) the following number of distortions has been found and listed:

Chapter 24 on global warming in "The Skeptical Environmentalist": 22 errors, 59 flaws, 81 in total.
                                                                                                     (This is more than one distortion per page).
"The Skeptical Environmentalist" in total (up to now): 118 errors, 219 flaws, 337 in total.
"Cool it!", British edition: 58 errors, 155 flaws, 213 in total (up to now, with about 45 % of the book investigated).
                                                                                       (This is more than two distortions per page). 

Al Gore´s book and film are not without errors. Several errors seem due to careless selection or presentation of examples, so that even though the actual details are wrong, the main point that they should illustrate is probably not wrong. In the words of the British high court judge, the presentation in the film is "broadly accurate".  However, there are a few points where the need to make the wake-up call as loud as possible has led to exaggerations of lurking dangers, or even to unfounded scare-tactics. This is unfortunate, because it reduces credibility also of those points which are probably correct.

However, when Al Gore and Lomborg are judged by the same standards, there is a wide difference in credibility. In those texts that deal with the climate issue, Lomborg has on average one to two flaws or errors per page. By comparison, Al Gore´s book has 325 pages. Even if we consider that, because of photos and large letters, this would compare to only 100 pages of Lomborg´s type, that would amount to only 0,13 flaw or error per page. In the film, there is on average one flaw or error every 9th minute. Even if you watch the whole film, you do not meet as many distortions as there are in 10 pages of one of Lomborg´s books.