Gore takes the prize; British judge less impressed

Instead of celebrating the news that my man Al Gore is sharing the 2007 Nobel Peace Prize with the thousands of scientists who supplied the raw material for the slide show that made him "the single individual who has done most to create greater worldwide understanding" of climate change, I am compelled to address a list of alleged errors in said slide show. Thank you High Court Justice Michael Burton. No really. Thanks.

As a member of Gore's Climate Project, the team our new Nobel laureate has entrusted to present his slide show, I could take umbrage at the mere notion of inaccuracies therein. But I won't, because the problems identified by the British judge are worth examining. They actually shed a good deal of light on the science of climate change and the scientific process.

So what are the errors? The anti-Gore blogosphere has kindly made the list readily available.

1. The film claims that melting snows on Mount Kilimanjaro evidence global warming. The Government's expert was forced to concede that this is not correct.

Good point. Several months ago, I removed any reference to Kilimanjaro from my version of the slide show precisely because of the lack of evidence tying the mountain's melting ice to global climate change. But good evidence that unrelated natural cycles in the Indian Ocean and East Africa may be to blame only came out earlier this year. Prior to that, it was fair to assume that Kilimanjaro was suffering from the same problems afflicting countless other glaciers and mountain ice caps around the world. Gore's presentation contains so many examples of glacial retreat, in fact, that many Climate Project members are forced to edit out most of them for time.

2. The film suggests that evidence from ice cores proves that rising CO2 causes temperature increases over 650,000 years. The Court found that the film was misleading: over that period the rises in CO2 lagged behind the temperature rises by 800-2000 years.

Now, that's not fair. Gore only associates CO2 levels and temperatures. The fact that CO2 sometimes lags behind temperature is irrelevant. As any competent climatologist will tell you, the fact that they are intimately linked is the problem -- change one and the other will follow, possibly setting off rapid feedbacks. Looks like the judge didn't bother to consult the RealClimate post titled "The lag between temperature and CO2. (Gore's got it right.)"

3. The film uses emotive images of Hurricane Katrina and suggests that this has been caused by global warming. The Government's expert had to accept that it was "not possible" to attribute one-off events to global warming.

Wrong. Gore actually makes it clear that isolated cases prove nothing, and only long-term, widespread trends are scientifically relevant.

4. The film shows the drying up of Lake Chad and claims that this was caused by global warming. The Government's expert had to accept that this was not the case.

Wrong again. Gore doesn't claim Lake Chad's fate is solely because of climate change. The consensus is perhaps half can be traced to climate change. And in any case, Lake Chad is used to illustrate the potential human consequences of increased demand for dwindling fresh water supplies, not as evidence for climate change.

5. The film claims that a study showed that polar bears had drowned due to disappearing arctic ice. It turned out that Mr Gore had misread the study: in fact four polar bears drowned and this was because of a particularly violent storm.

Fair point. But since the film was released, we have had several solid reports painting a grim picture of the future for the species, so I keep the polar bears in my presentation.

6. The film threatens that global warming could stop the Gulf Stream throwing Europe into an ice age: the Claimant's evidence was that this was a scientific impossibility.

Well, it could. And two years ago, when the film was made, many scientists were worried about the possibility, although most did not think that scenario was probable in the near future. Since then, however, those fears have been relegated to the margins, and again, I have removed that sequence from my presentations. Another example of how science evolves.

7. The film blames global warming for species losses including coral reef bleaching. The Government could not find any evidence to support this claim.

Then they should have looked harder. Many marine biologists are worried about the fate of corals in a warming, and lower pH ocean.

8. The film suggests that sea levels could rise by 7m causing the displacement of millions of people. In fact the evidence is that sea levels are expected to rise by about 40cm over the next hundred years and that there is no such threat of massive migration.

Wrong again. Yes, the film does suggest that -- but makes no time-frame prediction. Using outdated studies, the IPCC says that will happen, in more than a 1000 years. But since then, data on melting Greenland and West Antarctic ice packs have shortened the time involved. Jim Hansen says several meters within a century is a real possibility.

9. The film claims that rising sea levels has caused the evacuation of certain Pacific islands to New Zealand. The Government are unable to substantiate this and the Court observed that this appears to be a false claim.

Wrong yet again. The film does not claim that evacuations are already underway, only that they are being planned, and possibly imminent.

So when we eliminate the issues on which the judge was simply wrong, we are left with three issues in which either Gore's claims were not entirely supported by the science at the time, but subsequently have proven warranted, or Gore's claims were right at the time, but later proven unwarranted. More or less.

When you think about it, that's just about what you would expect from a science-based presentation about a rapidly evolving subject like climate change, delivered by a well-informed non-scientist. I'd have been surprised if everything Gore had said were still valid, and I'd be even more surpised if none of the science had changed since Laurie David and David Guggenheim filmed his presentations almost two years ago.

Apparently, the Nobel committee agrees with me. So I remain proud to be zero degree of separation from at least one of the recipients of this year's Nobel Peace Prize. (I have also interviewed more than one member of the IPCC, but then, who hasn't?)

Also, in case you were wondering, Gore writes that

My wife, Tipper, and I will donate 100 percent of the proceeds of the award to the Alliance for Climate Protection, a bipartisan non-profit organization that is devoted to changing public opinion in the U.S. and around the world about the urgency of solving the climate crisis.