Michael McCarthy: The climate disaster is upon us - now

Ten years ago, when the world was groping its way towards the signing of the 1997 Kyoto protocol, the sense that the issue needed to be tackled urgently was largely based on one thing only: computer programs.

Predictions from supercomputer models of the earth's atmosphere, about how global warming would progress, were the main drivers of that heroic effort to agree international reductions in the greenhouse gases which cause it.

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These immense mathematical structures looked forward a full century (and still do) at the rise in carbon dioxide in the earth's atmosphere, and how that would worsen the greenhouse effect; and their predictions were enough to get the Kyoto protocol signed (but not, thanks to George Bush, enough to make it work).

Yet what was almost completely missing from the climate debate a decade ago was observation: evidence of actual effects that the warming was having. This absence contributed to the sense, still widespread, that global warming is a distant problem, its consequences a century away.

Things have changed. Since the turn of the millennium, observations of the concrete effects of rising temperatures have started to mount up: the unprecedented European heatwave of 2003, which killed more than 30,000 people; the UK's record temperature topping 100F for the first time in that year; the record US hurricane seasons of 2004 and 2005, culminating in Katrina; and most of all, the melting ice.

The great ice masses are now shrinking rapidly everywhere; almost every mountain glacier, the great Greenland ice sheet, the great ice sheets of Antarctica, the legendary African snow on the top of Mt Kilimanjaro, and the ice of the Arctic, whose rate of disappearance, we now learn, has increased explosively.

It means two things: firstly, you can't deny it any more. Last week, we had the remarkable spectacle of The Economist magazine, climate change sceptic-in-chief, cheerleader to the American business community, coughing, shuffling, looking at its feet and admitting gruffly, well, perhaps there is something in this global warming stuff, after all.

Secondly, it's coming, to you. Doesn't matter you're not bothered about it. Doesn't matter you're thinking about your next holiday, or the state of your marriage or the next Big Brother. This vast phenomenon that is going to change the world unthinkably is coming right to your doorstep. A lot sooner than you think.