After two decades, the long scientific and political debate over whether human activities are warming up the Earth is finally over. Or is it? The world scientific community says so. Even the most recalcitrant governments, including the Bush administration, reluctantly agree. But the British media is characteristically unwilling to let an old row simply fade away.
On Thursday, Channel 4 will screen what it calls a "polemical and thought-provoking documentary" - The Great Global Warming Swindle - by one of the environmentalists' favourite hate figures, film-maker Martin Durkin.
It follows hot on the heels of a decision by David Miliband, the Environment Secretary, to send a copy of Al Gore's box-office hit, An Inconvenient Truth - which this month won two Oscars - to every secondary school throughout the country.
And the debate continues in the printed media with the Daily Mail and the Telegraph printing regular articles by sceptics and even The Independent, which - with this newspaper - presses for action to control climate change, giving space to the columnist Dominic Lawson, who rejects much of the green lobby's case. Yet, while contrarians remain common in broadcasting studios and newspaper offices, they are becoming increasingly hard to find in laboratories or governments.
Last month, the official Intergovernmental Panel on Climate Change (IPCC) - which brings together almost all the world's leading scientists in the field and all its governments - published the first instalment of its latest massive "assessment report", concluding that it was 90 per cent certain that human activities are heating up the planet. The conclusion was all the more authoritative as the IPCC is a cautious body that acts by consensus; all governments, including the United States, have to agree its conclusions.
Some scientists still disagree - that is the nature of science - but their numbers are diminishing, and few are leaders in their fields. A recent survey of 928 published scientific papers found not one that dissented over the reality of global warming. Even President Bush admitted - through gritted teeth - in January's State of the Union speech that the climate change presented "a major challenge".
Yet more recently, his main ally against the Kyoto Protocol, the Australian Prime Minister John Howard, has been forced into a U- turn by a massive Australian drought and an approaching election, announcing a ban on energy-wasting incandescent light bulbs.
And Mr Bush's best hope of a replacement - the Canadian premier, Steven Harper - has been forced by public opinion into a similar conversion.
But if environmentalists thought they could finally give up arguing, and focus entirely on promoting action, they can think again. For the clash between the Oscar-winning film and the Channel 4 production is likely to spark new public debate. Both are produced by controversial figures. Al Gore last week came under attack for hypocrisy, after it was revealed that he spends [pound]15,000 a year heating his home, 20 times more than the average American house. And, as The Independent on Sunday has repeatedly pointed out , he failed comprehensively to practise what he preaches when in Government.
Martin Durkin, for his part, achieved notoriety when his previous series on the environment for the channel, called Against Nature , was roundly condemned by the Independent Television Commission for misleading contributors on the purpose of the programmes, and for editing four interviewees in a way that "distorted or mispre-sented their known views".
Channel 4 was forced to issue a humiliating apology. But it seems to have forgiven Mr Durkin and sees no need to make special checks on the accuracy of the programme. For his part, the film-maker accepts the charge of misleading contributors, but describes the verdict of distortion as "complete tosh. …