An Inconvenient Truth

Al Gore in An Inconvenient Truth

Herald rating: * * * *

The PowerPoint presentation has come a long way. In this mostly riveting documentary based on a well-rehearsed lecture by former US vice-president Al Gore, the Earth seems to hang in the air behind the speaker, shimmering, blue, beautiful, fragile - and doomed.

The threat posed to the planet by global warming is the business of a dense but compact and lucid film. Gore, who disarmingly describes himself as "the man who used to be the next president of the United States" (he was, for those with short memories, the Democrat contender who received more votes than George W. Bush in 2000) is a fluent, if slightly wooden, presenter of the facts, few of which will be unknown to any who take an interest in climate change.

The film addresses head-on the question of scepticism in the scientific community about the threat posed - or whether any threat even exists. He mounts a soberingly persuasive campaign against the media's predilection for giving much more coverage to those who dispute climate change than to those who warn about it. But mostly he just runs through the numbers.

The fact that the numbers are presented with such visual flair - red lines on graphs assume the horrifying impact of a knife in a murder mystery; side-by-side pictures of glaciers shot 30 years apart depict entirely different landscapes - is what makes the film so compellingly watchable.

It also, not incidentally, feels deeply satisfying. Gore's material is like the best university lecture you have heard, full of facts so stunning that you don't know whether to use your hands to applaud or to cover your mouth in horror.

That's the film's strength, but it's also its weakness. US critics have noted that Gore's unpopularity with Republican middle America makes him a poor messenger. That will count for less internationally, but there is a sense that this is a film that preaches to the converted. Some of the graphic material seems more than a little tendentious, too; by my calculation, one graph which shows the difference between the Ice Age and 2050 would have the Earth's present average temperature hovering around 700C. And the scenes that depict Gore as a lonely warrior, on the road trying to save the planet, feel contrived and manipulative.

But on the whole, this is as important, shocking and thrilling a film as you will ever see. The fact that it had to be made at all is shameful; the need for it to be seen widely is urgent.

Director: Davis Guggenheim
Running time: 97 mins
Rating: PG
Screening: Rialto from next Thursday
Verdict: A mostly riveting documentary about climate change that occasionally lets its focus drift on to its presenter but is a compact precis of well-known and urgently important material