Figures collected by the Mauna Loa Observatory in Hawaii suggest that levels of CO2 are now 387 parts per million (ppm) – the highest they’ve been for 650,000 years.

The recordings also show that CO2 levels are increasing more rapidly: between 1970 and 2000, they rose by around 1.5 ppm per year, but since 2000, have been rising at a rate of 2.1 ppm per year, according to a report in the Guardian.

‘Despite all the talk, the situation is getting worse. Levels of greenhouse gases continue to rise in the atmosphere and the rate of that rise is accelerating,’ Martin Parry of the Intergovernmental Panel on Climate Change told the newspaper.

‘We are already seeing the impacts of climate change, and the scale of those impacts will accelerate until we decide to do something about it.’

This rapid increase in CO2 levels is thought to be caused by three things: a growing world economy, the use of coal by China and the decreasing ability of plants to soak up the gas.

Research at Bristol University has shown that this last phenomenon could be down to global warming: plants they studied took up less CO2 when they were in hot and dry conditions.

July 2008