ht has severely damaged the agricultural sector. Farmers are raising emaciated cattle and sheep. Cotton-lint production has plummeted. Wine grape and rice output has collapsed. Agricultural production has fallen by almost one-quarter in a year. And it is estimated that the drought has knocked three-quarters to 1 per cent off the country's growth as a whole.

And now the government is reaching for desperate measures. Australia's Prime Minister, John Howard, has announced there may be a ban on the use of the country's largest river system for irrigation unless there is significant rainfall over the next two months. The government is preparing to wrest regulatory control of the Murray and Darling rivers from the five states through which they run to ensure that water is reserved for urban drinking supplies and farmers' domestic use.

The Murray-Darling river basin has been called Australia's "food bowl". It generates about 40 per cent of the country's farm produce. If this tract of land - the size of France and Spain combined - is denied irrigation it would spell ruin for Australia's agricultural sector. Thousands of farmers could lose their citrus, almond and olive trees if they cannot be watered. Trees would die and production would be impossible for at least half a decade. Even if the rains do come in Australia in the coming weeks, as forecast, they will have to be especially long and prolonged to alleviate the crisis.

Moreover, this is a taste of things to come - not just for Australia, but the world. As the latest report from the United Nations Intergovernmental Panel on Climate Change makes clear, the runaway warming of the earth will bring severe drought in its wake. And the economic consequences will be disastrous. Sir Nicholas Stern's report for the Treasury outlined last year how climate change could be as economically traumatic as the Great Depression or the world wars of the 20th century.

There is already a growing drought problem in the Horn of Africa, most likely brought about by global warming. The Darfur crisis has been exacerbated by competition between Arab and African tribes for water resources. But this seems to be the first extended drought brought about by climate change in a developed country. It is a grim irony that Australia is suffering first. The country is led by a man who has helped to wreck concerted international action to slow climate change. Australia is the only industrialised nation, apart from the US, to refuse to sign up to the Kyoto Protocol. Mr Howard, along with President George Bush in the US, has formed an axis of denial over the seriousness of global warming. Earlier this year he suggested "the jury is out" on the link between climate change and man-made carbon dioxide emissions, despite the consensus among the world's scientists that such a link is pretty much beyond doubt.

But Mr Howard is now singing a rather different tune. His government recently announced plans to ban inefficient light bulbs to reduce Australia's carbon emissions. And now he prays for rain. This is because the drought is likely to be an important issue in Australia's elections this year. Mr Howard recognises that baiting asylum-seekers and posturing as President Bush's "deputy sheriff" in the Pacific is not enough. Suddenly, the environment matters.

Today, Australia; tomorrow, vast areas of the world's surface: the imperative for the world's leaders to take serious action to curb climate change has never been starker.

http://comment.independent.co.uk/leading_articles/article2465904.ece