UN: Carbon dioxide levels reach new high

Nov 23, 2007, 16:57 GMT

Geneva - Global concentrations of carbon dioxide (CO2) in the atmosphere reached their highest levels ever recorded in 2006, according to the latest Greenhouse Gas Bulletin published Friday by the UN weather agency, the World Meteorological Organization (WMO).

Concentrations of nitrous oxide also reached a new high while methane remained almost unchanged.

After water vapour, CO2, methane, and nitrous oxide are the three most prevalent greenhouse gases in the earth's atmosphere and largely responsible for driving global warming and climate change.

WMO senior scientific officer, Geir Braathen, said: 'If there is at least one greenhouse gas you have to do something about it is CO2. It contributes the very largest part of greenhouse gas.'

He said methane levels had stabilized because the lifespan in the atmosphere was shorter. Any efforts to reduce methane produced a more immediate result.

The 36-per-cent rise in CO2 since the beginning of the industrial age in the late 1700s has been due mainly to emissions from the combustion of fossil fuels, according to the WMO.

Around one third of nitrous oxide discharged into the air is a result of human activities such as fuel combustion, biomass burning and some industrial processes.

Methane is produced from fossil fuel exploitation, landfills and ruminant farm animals with up to 40 per cent occurring naturally.

The bulletin is published just before the anniversary of the Kyoto Protocol which was signed on December 11, 1997 when governments agreed to work to cut greenhouse gas emissions. More than 179 countries have now signed up to the agreement.