The U.K. government's chief scientific adviser said the current rise of carbon dioxide in Earth's atmosphere may be just an aberration, not the start of a trend.
Sir David King told BBC News Online the rise in CO2 – which, at 375 parts per million, is higher than at any time in recorded history, is likely to be an anomaly, which would not be unprecedented, and not the start of a trend, unless it is proved otherwise.
CO2 is the main gas produced by such human activities as burning fossil fuels deforestation. It also is the main suspect in the phenomenon of global warming.
The amount of atmospheric CO2 has increased by an average of 1.5 parts per million each year, as more greenhouse gases are emitted. According to measurements at the Mauna Loa observatory in Hawaii, in 2002 and 2003 the increase was more than 2 ppm.
Another British scientist, Peter Cox, who heads the carbon cycle group at the Hadley Center for Climate Prediction and Research, noted the CO2 increase was not uniform across the globe. He said the shift might have been caused by something unusual in the northern hemisphere.
For example, he said, Europe's very hot summer in 2003 and unusually large number of forest fires could have killed off vegetation and increased carbon releases from the soil.
