Davis Guggenheim's documentary, 'An Inconvenient Truth', is based on a slide show by former US Vice President Al Gore about the dangers of climate change and global warming. That might not sound like the most exciting evening at the cinema but 'An Inconvenient Truth' may be the most important film you get to see this - or any - year. 

Basically, the facts are simple. Global warming is real. It is happening as the result of human activities. It is already having an effect throughout the world and, unless we take prompt action, it will have catastrophic consequences. So that's the science bit. But, what makes this doomsday prediction palatable, and even entertaining, is the pull-no-punches presenter who introduces himself saying, to much audience laughter: "I am Al Gore, I used to be the next president of the United States."

Striking images, scary statistics and a concise litany of facts from Gore's well-polished and much-travelled presentation are cut with more personal insights into his life. While, at times, the film moves towards becoming a party political broadcast on behalf of a surprisingly warm Al Gore, this focus on the individual is always counterbalanced by evidence of his long term commitment to global warming education. He does manage to get plenty of political digs in and we're left in no doubt as to what he thinks about the current administration but, politics aside, the case he presents is relentless, fascinating and fearsome. If you have children, for their sakes - and for those generations as yet unborn - you cannot refuse to see this film. An inconvenient truth, perhaps, but maybe an avoidable one.

Caroline Hennessy