Global warming 'far faster than expected'
The Independent (UK), Nov. 9, 2000
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, unveiled 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 (CO2) -- 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 CO2 -- will, as temperatures steadily rise, suddenly change from being an overall absorber of CO2 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 CO2 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 CO2 -- 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 CO2 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.
Reuters News Service, Nov. 9, 2000
LONDON - Global warming could happen faster than scientists expect because forests, instead of mitigating climate change, could speed it up, researchers said yesterday.
As environment ministers prepare for a major climate change conference in the Hague next week, scientists at Britain's Hadley Centre for Climate Prediction and Research said planting forests to absorb carbon dioxide (CO2) and reduce global warming could be counterproductive.
Two studies published in the science journal Nature using computer models of global warming show that as temperatures rise, forests, or so-called carbon sinks, are likely to emit more CO2 into the atmosphere, leading to further warming of the climate.
"Our initial results suggest that vegetation and soils, which currently absorb about a quarter of human-made carbon dioxide emissions, could accelerate future climate change by releasing carbon to the atmosphere as the planet warms," said Dr Peter Cox.
The findings could have important implications for the Hague meeting because the use of carbon sinks is one of the key issues that will be debated at the two-week conference.
Ministers from around the world will try to seal an international agreement to cut emissions of CO2 by an average of five percent of 1990 levels by 2008-2012 in line with a treaty agreed in Kyoto, Japan in 1997.
The Kyoto treaty allows countries to plant forests to offset some of their CO2 emissions.
"All we can say... is that if you want to plant trees to absorb CO2 in order to offset additional future emissions there are a huge amount of uncertainties," Dr Geoff Jenkins, head of the Hadley climate change programme, said in a telephone interview.
"On the other hand if you refrain from emitting carbon into the atmosphere you know where you are in terms of its effect on CO2. So there is a big difference in the uncertainty levels between those two courses of action," he added.
Environmental groups Greenpeace and WWF are calling for carbon sinks to be excluded from the Kyoto treaty. Both groups want industrialised countries to achieve their targets by cutting emissions.
"Claiming credit for carbon stored in trees is a blatant attempt by some countries to cheat on their Kyoto commitments," Bill Hare, Greenpeace International's Climate Policy Director, said in a statement.
The second study in Nature by Dr Richard Betts also showed that planting new forests in cold parts of the world like Siberia and Canada could be doing more harm than good.
This is because in northern countries, where the ground is covered in snow, forests absorb more of the sun's heat than the terrain. The additional exposure to the sun has a warming influence that could offset part of the cooling effect of the CO2 uptake.
Britain's Environment Minister Michael Meacher said the research highlighted the importance of The Hague conference and the difficult negotiations ministers will face.
"These results add weight to our view that we must achieve real emission reductions to meet Kyoto targets, and confirm our concerns about sinks. We must be cautious about them," he said in a statement.