My forecast for brighter spells

Long was I sceptical about global warming. My reasoning had nothing to do with the evidence of temperatures rising or glacial ice sheets melting, but the bare fact that not once had my trusted television weather presenter ever used the term.

Life would have been so much different, of course, had I heard her say: 'And tomorrow the high will be 28 degrees and the low 24, and better take a hat to work because there is sure to be a lot of global warming about.' Alas, she has never uttered this sage advice, so I remained a doubter.

Nor did I awaken to find that a season had been skipped and that leaves were falling, red-hot and smoking, from trees in the middle of spring - or opened my fridge to find the eggs already done. Sea levels have not risen terribly perceptibly, nor storms become noticeably more numerous.

All that changed this week when Al Gore, who used to be the next president of the United States, blew into town with his documentary An Inconvenient Truth. I haven't seen the film yet, but everyone I know who has says it presents such a convincing argument that global warming exists that they intend to send their weather presenter a letter - as soon as they stop popping anti-depressants.

The thought of the dull and wooden Mr Gore giving a slide show would make the most tedious job I've ever considered - making little, white plastic horses for whisky bottles - seem interesting.

But this man is a politician at heart. Combine that with his new roles of educator and environmentalist and - rather than a lecture - you apparently get a compelling story that turns hardened sceptics into angry, then determined, climate defenders.

Using a cartoon of the world, Mr Gore explains that the thin layer of atmosphere enveloping the Earth is being thickened by gases, like carbon dioxide, which are produced by human activity. He shows, with graphs, that the more carbon dioxide we produce, the more global temperatures rise.