Measurements of increasing carbon dioxide in the atmosphere is worrying climate scientists. Dr Craig Wallace from the Tyndall Centre for Climate Research said "If it's the start of a real trend then this potentially is very serious indeed. The time for halting climate change actually went and passed in the late 1980s. What we can do now is hopefully slow down climate change, mitigate climate change by following the precedent set by the Kyoto Climate Agreement."
A US climate scientist, Charles Keeling, has reported that for the first time, carbon dioxide levels in the atmosphere rose by more than two parts per million for two years running, from 2000 to 2001.
He said : "The rise in the annual rate to above two parts per million for two consecutive years is a real phenomenon."
"It is possible that this is merely a reflection of natural events like previous peaks in the rate, but it is also possible that it is the beginning of a natural process unprecedented in the record." he said.(2)
The levels were measured on top of Mauna Loa in Hawaii. Between 2001 and 2002 the number of parts per million of carbon dioxide rose from 371.02 to 373.10, an increase of 2.08 over the year. Then it rose again in 2003 to 375.64, an annual increase of 2.54.
Such increases in the past have been associated with the El Nino phenomenon that periodically disrupts weather patterns in the Pacific Basin. But El Nino has not ocurred to match these recent increases.
Mr Keeling said one explanation for the rise "could be a weakening of the earth's carbon 'sinks' [oceans and forests], associated with the world warming, as part of a climate change feedback mechanism."
Peter Cox, who heads the carbon cycle group at Britain's Hadley Centre for Climate Prediction and Research, was more sceptical saying it was possible to read too much into the figures. He also pointed out that the increase in carbon dioxide was not uniform across the globe and suspected something unusual had happened in the Northern Hemisphere. He proposed that the very hot summer last year in Europe, and more forest fires may have killed off vegetation thus increasing carbon releases from the soil.(1)
Dr Piers Forster, senior research fellow of the University of Reading's Department of Meteorology, said: "If this is a rate change, of course it will be very significant. It will be of enormous concern, because it will imply that all our global warming predictions for the next hundred years or so will have to be redone." (2)
ABC London correspondent, Kirsten Aiken, interviewed Chris Jones from the UK's Hadley Centre for Climate Change for ABC Radio - AM program:
"What we think is happening is that the natural vegetation, the forests and so on, which normally absorb a certain amount of the fossil fuel emissions, have started to absorb less of that as a response to the 2003 very warm summer." said Chris Jones.
He further elaborated to Kirsten Aiken what it meant: "Well, on its own all it shows is that the natural carbon cycle has a sensitivity to climate, but the wider implication is that in the future if these warmer summers become the norm, which is what we expect in terms of global warming scenarios, then we may see a feedback where the changes in climate cause a long-term increase in carbon dioxide on top of the fossil fuel emissions, and that in itself could increase the warming in a sort of positive feedback." (3)
Kirsten Aiken also spoke to Dr Craig Wallace from the Tyndall Centre for Climate Research. He provided a sobering warning that the increase could mean rapid climate change is already in progress.
"It could just be a temporary blip. If it's the start of a real trend then this potentially is very serious indeed. The time for halting climate change actually went and passed in the late 1980s. What we can do now is hopefully slow down climate change, mitigate climate change by following the precedent set by the Kyoto Climate Agreement." he said.(3)
UK Director of Greenpeace, Stephen Tindall, hoped news of the increase in CO2 levels will provide the impetus for governments to tackle climate change. He singled out Australia for special mention, describing it as one of the world's biggest carbon dioxide polluters which has failed to make any real moves to address what is shaping up as the globe's greatest threat.
"We can see that politicians are slowly beginning to move, not nearly fast enough of course, but at least there is some movement. So in recent weeks we've seen Kyoto being ratified by the Russians, which means that it will finally come into force."
"We've even seen the Bush administration in the US finally accepting the science of climate change. So that begins to make the Australian Government look extremely isolated." said Stephen Tindall.(3)
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Sources:
(1) ABC Online - Carbon dioxide spike renews global warming fears
http://www.abc.net.au/news/newsitems/200410/s1217958.htm
(2) The Guardian - Climate fear as carbon levels soar
http://www.guardian.co.uk/climatechange/story/0,12374,1324379,00.html
(3) ABC Radio - AM Transcript - Global warming fears heightened by carbon dioxide increase
http://www.abc.net.au/am/content/2004/s1218111.htm
(4) Image from Wikipedia - Global Warming
http://en.wikipedia.org/wiki/Global_warming
Reference:
(5) The Discovery of Global Warming
http://www.aip.org/history/climate/