Leading article: The planet's chance of a lifetime

Finally, as the world's nations meet in Bali for what is almost certainly their last shot at beginning to avert catastrophic global warming, there are signs that Britain and the United States are starting to measure up to the immensity of the task. Our exclusive top story today reveals that business secretary, John Hutton - after trying to block a much needed expansion of renewable energy in Britian, and being smartly rapped over the knuckles by Gordon Brown for his pains - will announce one of the world's biggest exopansions of windpower. And the news from the United States - which has so far combined the farsightedness of an ostrich and with the flexibility of a mule in its approach to climate change - is, if anything, even more startling: as we also report, both houses of Congress - long seen as an obstacle to action - are driving forward measures that would put the country in its rightful place in the lead of then international effort to head off disaster. And under the pressure even President Bush's instransigence is begning to crack.

None of this comes a moment too soon. In fact it is desperately late. The accumulating scientific evidence, which seems to get more alarming by the day, shows that global warming is proceeding further and faster than anyone expecteed or than the scientists ever predicted. The accepted wisdom for the last two years has been that we have less than a decade in which to start drastic action to start cutting emisisons of greenhouse gases by a massive 80 per cent by 2050. Two years of that decade have now gone, and it looks as if even that timescale may be overoptimistic if we are to keep the heating of the planet at or below two degrees centigrade above the level in which human civilsations have formed and flourished - the threshold above which truly catastrophic changes are expecetd to take place. Yet the lumbering process of international negotations is nowhere near being up to the job. The best we can hope for in Bali is an agreement on a roadmap for future talks; the best eventual outcome a new - more radical - international treaty to be agreed at the end of 2009. Then world simply cannot afford to wait for this. Heavy polluters will have to take immediate action. And that is why last week's developments in Britain and the United States are so necessary, and so welcome.

Britain has long talked a good game over climate change, but performed on the field with a laziness and lack of commitment that would shame even the paralytic performance of England's footballers against Croatia. Tony Blair did indeed do well in raising the international profile of the issue but under his watch the country's carbon dioxide emissions actually increased. Gordon Brown gave an excellent speech on the subject last month - full of bold vision and concrete commitments - but then promptly annunced the construction of a third runway at Heathrow. Ten days ago the UN's most prestigious publication, The Human Development Report, exploded ministers' oft-repeated claim to lead the world in action over climate change. Indeed it singled Britain out for particular, forensic criticism and - in passing - made it abundantly clear that the Climate Change Bill before Parliament does not go far enough.

Nothing in this sorry story has been so shameful as Britain's failure to exploit renewable energy. Its winds, waves and tides make up the richest resource of non-polluting power in Europe, yet we are second to bottom of the continental league table in expoliting it. For decades a recalcitrant, blindly pro-nuclear treacle layer in the old Department of Tade and Industy frustrated all attempts to expand it properly. Just weeks ago they were at it again - reincarnated in John Hutton's department- lobbying to scrap European targets for renewables on the grounds that they would impede the advance of the atom. Gordon Brown did well to face them down and insist that Britain retained and met the targets.He has done even better in following through, first with plans to exploit all forms of tidal energy - announced in last month's green speech - and now with setting in motion this expansion of offshore wind. This is more like the Gordon Brown we thought we were getting this summer, before this autumn's wobbles and weaknesses.

In the US the last excuse for inaction has melted away. For the last decade Congressional opposition to action has been paraded as the ultimate deterrent. To some extent that has been the case, though it has been overblown: the Senate's famous 1997 unanimous resolution against an international treatry that did not include developing countries was a warning shot during the negotiations leading up to Kyoton not, as almost always presented, a rejection of the agreed Protocol. But at any rate the excuse is now blown. With both houses of Congress pressing for action, 26 state governments taking often radical individual measures, top businesses pressing for change, and public opinion crying out for it, stringent steps are now politically as well as scientifically essential. Over to you, Mr Bush.