Geoffrey Lean: Mr Cameron heads for Arctic wastes, and a cold wind blows for the PM

Some scientists think the ice will go on melting irreversibly

Where in the world might one reasonably expect David Cameron to be next week, as his first election campaign enters its final stages?

In Carshalton trying to boost the Conservative vote in the local polls by talking about council tax, perhaps? In Solihull campaigning on schools? In Redcar, rabbiting on about recycling? All are, literally, thousands of miles off the mark. As we report on page 3, he'll be in Svalbard, going on about uggianaqtuq.

Why? Svalbard is an icy group of Arctic islands, including Spitzbergen, so far best known as where Philip Pullman's Northern Lights heroine and her attendant daemon are captured by armoured bears.

And uggianaqtuq? That's what the Inuit people call the changes to their climate from global warming. It means "a friend acting strangely".

David Cameron's own attendant demons, on his right, ridicule the trip. "Barmy!" says one shadow minister. Frederick Forsyth lists it as a source of "disenchantment", while Charles Moore dismisses global warming as "drivel".

But there is method in the apparent madness. The Tory leadership is making the environment - where Labour appears to be particularly vulnerable - the centrepiece of its final campaign push. Cameron's three-day, 4,000-mile round trip, and the speech on global warming that he is to deliver in Oslo on the way back, are designed to force attention to the issue.

It already seems to have had some effect. For Gordon Brown - an armoured bear, if ever there was one - is to make a speech on global warming himself, only his second on the subject, on Thursday, while his future prime-ministerial rival is on the ice.

Certainly, as one of the Chancellor's closest colleagues acknowledged yesterday, Mr Cameron has driven climate change up the political agenda. And he is being vindicated by other authoritative voices.

Three weeks ago the Archbishop of Canterbury predicted that "billions" could die from global warming.

And Professor Sir David King, the Government's chief scientific adviser, predicted on Friday that, even on optimistic assumptions, global temperatures would rise far above the maximum safe level.

Certainly, too, the Arctic is the place to go. The thermometer is rising twice as fast there as on the rest of the planet; permafrost is thawing; trees are moving north and the Inuit - who have a thousand words for "reindeer", but none for "robin" - are struggling to extend their language as temperate species flock up from the south.

This summer the Arctic ice cap shrank to a record low for the fourth successive year. Even more ominously, it failed to rebound adequately this winter, as temperatures remained some 5C above the normal. Some scientists believe it has now passed a "tipping point", and the ice will go on melting irreversibly.

Mr Cameron - who is being taken to Svalbard by WWF - will inspect a melting glacier before heading to Oslo to make a speech promoting "green taxes" to tackle the problem.

Before he leaves on the trip, he will launch a green manifesto to set the theme for the final stage of the local election campaign. Further environmental initiatives and announcements are scheduled for the coming weeks.

The Tory leader showed little interest in the subject before standing for the leadership. But last November, he put forward the most radical measures to tackle climate change ever proposed by a top British politician. And, on winning, he took up the issue in his acceptance speech and first Prime Minister's Questions, appointed some of his greenest MPs as shadow ministers, and established a policy commission under John Gummer and Zac Goldsmith.

Close colleagues say that he now fully "gets" the environmental message. But they add that green issues were deliberately chosen both to show that the Tory party was going to change and to move into a vacuum left by Labour. "What is morally right is also electorally clever," said one.

One opinion poll found 36 per cent of respondents more likely to vote Conservative because of Mr Cameron's promise to tackle global warming, with only 5 per cent less likely.

Bob Worcester, the head of Mori, doubts these figures, but still believes that Mr Cameron is shrewd to target the issue. Twenty-two of the 31 seats the Conservatives won from the Government last year, he says, fell because a Liberal Democrat surge took Labour votes. And apart from Iraq (on which the Tories can hardly recant) the environment was the Lib Dems' most attractive issue.

The latest Mori tracking polls also show that more people believe the environment will get worse under Labour than anything else, making it their most vulnerable issue.

Gordon Brown is certainly giving it much more attention. This month he launched a joint programme to boost biofuels with Brazil, South Africa and Mozambique and he is pressing at the World Bank for a $20bn-a-year investment package in clean energy in the Third World.

And this week he will make his climate change speech in New York, in an implied challenge to President Bush; despite much urging, Tony Blair has always refused to take such an initiative in the United States.

The Chancellor is much concerned to be seen to deliver on the issue, not just to talk about it. His test will come later this year over whether he backs tough, or lax, limits on pollution from industry under EU global warming measures.

All this is leaving the Prime Minister behind. Despite much rhetoric, he has failed to deliver. Britain's emissions of carbon dioxide have risen since he took power, and he has opposed measures to bring them down.

Privately, he shows little interest in practical action at home, preferring to concentrate on trying to design a new international treaty which would include the US, China and India. But as his power and authority ebb away, foreign governments are reluctant to make deals with him.

It is a sorry end for the leader who has done more than any to put the issue on the international agenda. But the political climate, as well as the natural one, is changing. And though it is Mr Cameron who goes to the frozen north next week, it is Mr Blair who looks like being left out in the cold.

Alan Watkins is away