Diligent, long-suffering readers of this blog will recall that one of the strengths of Al Gore’s global warming documentary “An Inconvenient Truth” is a study he cites that supposedly demonstrates how the vast majority of scientists are in agreement about global warming, and that the debate should therefore be over.
The study was by Nancy Oreskes. According to Gore, she randomly chose 928 global warming-related articles published in science journals between 1993 and 2003 and found that ALL of them supported the majority view — i.e., Gore’s position, that global warming is real, bad and preventable.
I said in a previous blog entry that I have no choice but accept that study as legitimate. I don’t have access to all the science journals, nor the resources to duplicate the study. I said someone who did have the resources was probably already working on either refuting or supporting it.
And I was right! And it turns out Oreskes’ study — and thus Gore’s support of it in his film — was deeply flawed.
A reader named Keryn (I offer no comment on that spelling) pointed me toward an article by Iain Murray published in the National Review. Now, the National Review would sooner open an abortion clinic in its conference room than say anything positive about Al Gore, and much of what Murray says boils down to nothing more than “my scientists are better than Gore’s scientists.” But he does offer a key insight, found in item #24:
On the supposed Ã¢â‚¬Å“scientific consensusÃ¢â‚¬?: Dr. Naomi Oreskes, of the University of California, San Diego, did not examine a Ã¢â‚¬Å“large random sampleÃ¢â‚¬? of scientific articles. She got her search terms wrong and thought she was looking at all the articles when in fact she was looking at only 928 out of about 12,000 articles on Ã¢â‚¬Å“climate change.Ã¢â‚¬? Dr. Benny Peiser, of Liverpool John Moores University in England, was unable to replicate her study. He says, Ã¢â‚¬Å“As I have stressed repeatedly, the whole data set includes only 13 abstracts (~1%) that explicitly endorse what Oreskes has called the Ã¢â‚¬Ëœconsensus view.Ã¢â‚¬â„¢ In fact, the vast majority of abstracts does (sic) not mention anthropogenic climate change. Moreover — and despite attempts to deny this fact — a handful of abstracts actually questions the view that human activities are the main driving force of Ã¢â‚¬Ëœthe observed warming over the last 50 years.Ã¢â‚¬â„¢Ã¢â‚¬?
The way it went down was, Oreskes’ study was published Science Magazine on Dec. 3, 2004. In it, Oreskes said she had done an Institute for Scientific Information (ISI) database search for the keywords “climate change” and had come up with 928 abstracts published between 1993-2003, and that not one of them rejected the consensus position.
When Dr. Benny Peiser did the same search, however, he came up with some 12,000 papers, not 928. Confronted with this information, Oreskes confirmed she’d screwed up: She hadn’t searched for the keywords “climate change,” as her article said, but for “global climate change.” That search brings up only 1,247 documents. (Where she got the number 928, who knows.)
Seeing that Oreskes’ study was flawed from the get-go, Peiser did his own. He used the same keywords — “global climate change” — for 1993-2003 and came up with 1,247 documents, as just mentioned. Only 1,117 of those had abstracts (you know, the paragraph that summarizes the whole paper). He analyzed those 1,117 abstracts and found that only 13 explicitly endorse the consensus view; 322 implicitly accept it but focus on other aspects; 44 focus on natural factors of global climate change; and 34 reject or doubt the Al Gore view altogether. (Oh, and 470 of the 1,117 articles include the keywords “global,” “climate” and “change” but don’t actually have anything to do with the matter at hand.)
Science Magazine ran a brief correction a few weeks later, but refused to published Peiser’s more detailed study on the grounds that the information he was presenting was already widely disseminated on the Internet. (In other words: “Yeah, we screwed up when we ran Oreskes’ article. Quit rubbing it in.”)
Peiser recounts the whole thing, including his exchanges with Science Magazine, here. It’s good reading.
Several readers also brought to my attention an article from the Wall Street Journal that argues with some more of Gore’s points. This article also mentions the Oreskes/Peiser studies.
The inaccuracy of the Oreskes study hurts part of Gore’s case: the part where he says scientists all more or less agree with him. In truth, while there is a majority opinion (MOST scientists seem to be onboard with it), it’s far from being an overwhelming consensus. I suspect average non-scientist citizens will decide what to believe the same way they usually do: They’ll agree with Gore if they’re Democrats and disagree with him if they’re Republicans. Ta-da!
Final side note/tangent: Many conservative pundits, including my occasional employer Glenn Beck, insist on declaring Gore’s film a box-office failure and mocking him for it. They say this because they wish it to be so, not because the facts support it.
(Glenn Beck has compared the film to Hitler’s propaganda. I suppose it’s his job to stir up controversy by making extreme statements, thus ensuring more attention for himself. Hitler, I mean. Oh, and I guess Glenn, too.) (But I kid.)
The film has grossed $13.6 million to date, making it the fifth most successful documentary of all time. It will be in fourth place by the time it’s finished. (It needs just another $1.5 million to overtake “Madonna: Truth or Dare,” but probably won’t muster the $7 million it needs to kick “Bowling for Columbine” out of the No. 3 spot.)
Yes, $13.6 million is nothing compared to the top grossers of the day. But no reasonable person would compare a documentary to a wide-release Hollywood blockbuster. By any sane system of measurement, $13.6 million for a documentary is fantastic. You can argue with the movie’s facts, agenda or presentation, but on the matter of its box office, there IS a consensus and the debate IS over.