The next IPCC report is leaking out, and the idea seems to be that it may not be a good idea to wait until heat waves and storm surges begin to make our cities miserable before we act.

In 20 years, tens of millions more Latin Americans and hundreds of millions more Africans will be short of water, and by 2050 one billion Asians could face water shortages. The glaciers of the Himalayas, which feed the great rivers of the continent, are likely to melt away almost completely by 2035, threatening the lives of 700 million people. And when your resources run out, you go try to take someone else’s.

Scientists from the Intergovernmental Panel on Climate Change (IPCC) are meeting in Brussels this week to chart the consequences of global warming on populations and ecosystems worldwide and agree possible measures to tackle it.

Melting glaciers, rising sea levels, heatwaves, droughts – the effects of rising global temperatures are already widely felt around the world.

But the poorest nations are set to suffer more, and are the least prepared to cope with the expected consequences, climate scientists will warn on 6 April 2007.

If this is what a watered-down version of caastrophe looks like, the original version can hardly have been cheerful.

The report, by the Intergovernmental Panel on Climate Change, is the second instalment in a series of three widely anticipated studies on global warming to be issued this year by the body. The report is the collective work of more than 1,000 of the world’s scientists.

This new instalment outlines the far-reaching impact that global warming is already having and expected to have over the next few centuries on the world’s environment, ranging from freshwater fish to mangroves and boreal forests.

When it’s the world’s leading scientists against the Conservative leader, it’s good to go with the scientists.

More on the IPCC report. It’s no longer a matter of politics, or waiting for scieintific confirmation. Climate change is here.

By 2050, snowmobiling could be history in Eastern Canada, a quaint winter pastime from the days of yore. It will be just too warm to have reliable snow.

People who like skiing in Banff on real snow better get on the slopes now and enjoy it while they can. The ski season could become truncated, perhaps by as much as 14 weeks a year at higher elevations.

And consumers with a soft spot for California wine would also be advised to sip favourites now: the state could become too hot to support current crop yields, according to the IPCC.

Global warming scientists are under intense pressure to water down findings, and are then accused of silencing their critics.