Global warming is accelerating three times more quickly than feared, a series of startling, authoritative studies has revealed.
They have found that emissions of carbon dioxide have been rising at thrice the rate in the 1990s. The Arctic ice cap is melting three times as fast - and the seas are rising twice as rapidly - as had been predicted.
News of the studies - which are bound to lead to calls for even tougher anti-pollution measures than have yet been contemplated - comes as the leaders of the world's most powerful nations prepare for the most crucial meeting yet on tackling climate change.
The issue will be top of the agenda of the G8 summit which opens in the German Baltic resort of Heiligendamm on Wednesday, placing unprecedented pressure on President George Bush finally to agree to international measures.
Tony Blair flies to Berlin today to prepare for the summit with its host, Angela Merkel, the German chancellor. They will discuss how to tackle President Bush, who last week called for action to deal with climate change, which his critics suggested was instead a way of delaying international agreements.
Yesterday, there were violent clashes in the city harbour of Rostock between police and demonstrators, during a largely peaceful march of tens of thousands of people protesting against the summit.
The study, published by the US National Academy of Sciences, shows that carbon dioxide emissions have been increasing by about 3 per cent a year during this decade, compared with 1.1 per cent a year in the 1990s.
The significance is that this is much faster than even the highest scenario outlined in this year's massive reports by the Intergovernmental Panel on Climate Change (IPCC) - and suggests that their dire forecasts of devastating harvests, dwindling water supplies, melting ice and loss of species are likely to be understating the threat facing the world.
The study found that nearly three-quarters of the growth in emissions came from developing countries, with a particularly rapid rise in China. The country, however, will resist being blamed for the problem, pointing out that its people on average still contribute only about a sixth of the carbon dioxide emitted by each American. And, the study shows, developed countries, with less than a sixth of the world's people, still contribute more than two-thirds of total emissions of the greenhouse gas.
On the ground, a study by the University of California's National Snow and Ice Data Center shows that Arctic ice has declined by 7.8 per cent a decade over the past 50 years, compared with an average estimate by IPCC computer models of 2.5 per cent.
In yesterday's clashes, masked protesters hurled flagpoles, stones and bottles and attacked with sticks forcing police to retreat. The police said they were suffering "massive assaults" and that the situation was "very chaotic". They put the size of the demonstration at 25,000; organisers said it was 80,000.
Further reading: Go to pnas.org/cgi/doi/10.1073/pnas.0700609104