Global warming 'far faster than expected'

Global warming is likely to take place 50 per cent faster and result in much more damage than previously thought, according to remarkable new computer predictions by British scientists.

Global warming is likely to take place 50 per cent faster and result in much more damage than previously thought, according to remarkable new computer predictions by British scientists.

The new scenario, released by the Government yesterday, implies a grim future for billions of people around the globe, with even more damaging impacts than have so far been expected in terms of droughts, extreme weather events such as hurricanes, rainstorms and flooding, and sea-level rise.

"This is a further wake-up call to what is the worst problem the world faces today," said the Environment minister Michael Meacher, who announced the findings. "The severity of this cannot be overstated."

The research, by scientists from the Met Office's Hadley Centre for Climate Prediction and Research in Bracknell, Berkshire, was released as meteorologists said this autumn may be the wettest in Britain since records began in 1727. Heavier rain in northern latitudes has been predicted as a consequence of global warming for some time.

The newly predicted speed-up in warming will happen, the researchers believe, because the ability of the earth's soils, vegetation and oceans to absorb carbon dioxide (CO ₂) - whose increasing presence in the atmosphere is causing climate change - will be compromised by climate change itself.

The carbon cycle - the biochemical process of absorption of CO ₂ - will, as temperatures steadily rise, suddenly change from being an overall absorber of CO ₂ to an overall emitter, and give a boost to the greenhouse effect in a "feedback loop".

According to the Hadley Centre's supercomputer model of the global climate, this will start to occur about 2050, when the northern part of the Amazon rainforest starts to die. From acting as a "sink", absorbing carbon, much of the world's vegetation and soils will then start acting as a carbon source, giving out CO ₂ and adding to the greenhouse effect. The uptake of carbon by the oceans will similarly decline.

As a result, the increase in mean global temperature by 2100, previously estimated at about 3C from the present, will be closer to 4.5C, said Dr Peter Cox and other researchers. Over land, where increases will be higher, the previously estimated 4C temperature rise will probably be about 6C.

In the past, the carbon cycle was discounted as something that would not alter. "People thought the biosphere was passive, but we know that the carbon cycle is sensitive to climate," Dr Cox said. These newly predicted rises are enormous and likely to be highly destabilising to the earth and its life-support systems, and to alter the physical face of the globe. By 2080, for example, the researchers now believe most of the ice in the Arctic ocean will have disappeared in summer.

In a further piece of new research, Hadley Centre scientists led by Richard Betts say that the idea of combating climate change by planting big forests as "sinks" to absorb CO ₂ - much favoured by the Americans as an easy alternative to cutting back their emissions from motor vehicles and industry - may be a non-starter.

New forests will make the land surface darker and so able to absorb more of the sun's heat instead of reflecting it out into space - and the net effect may be a still further warming.

The findings are published today in the journal Nature, five days before the start of a conference in The Hague that will attempt to close loopholes in the Kyoto Protocol, the 1997 agreement on cutting CO ₂ and other greenhouse-gas emissions.

Agreement at The Hague was vital, Mr Meacher said yesterday. "I think public opinion has, up until now, underestimated how drastic and severe these phenomena are," he said.

In a third piece of research, reported in New Scientist today, scientists at the Tyndall Centre for Climate Change Research at the University of East Anglia say some countries will warm up more than twice as much as others in the coming century.

They predict more than 5C of warming for a string of Asian countries that are already among the hottest in the world, including Uzbekistan, Tajikistan, Afghanistan and Iran.

* An environment policy unit has been created at the Foreign Office, reflecting the growing importance of green issues in international affairs.