The United Nations' weather agency, the World Meteorological Organization (WMO) has announced that concentrations of greenhouse gases carbon dioxide, methane and nitrous oxide reached a new high last year.

"The major greenhouse gases - CO2, methane and N2O - have all reached new highs in 2007. Two of them, CO2 and N20, are increasing steadily and there is no sign of leveling off of those two gases," WMO expert Geir Braathen said.

Braathen added that it was too early to tell if methane would keep rising.

Latest numbers published in the WMO's 2007 Greenhouse Gas Bulletin show that carbon dioxide reached 383.1 parts per million (ppm), an increase of 0.5% from 2006.  Concentrations of nitrous oxide also reached record highs in 2007, up 0.25 percent from the year before, while methane increased 0.34%, exceeding the highest value so far recorded in 2003.  Using the NOAA Annual greenhouse gas index, the total warming effect of all long-lived greenhouse gases was calculated to have increased by 1.06% from the previous year and by 24.2% since 1990, WMO said.

WMO figures show the levels of CFCs continued to decrease slowly, which can be seen as a good message.  

"The Montreal Protocol, through the phase-out of ozone-depleting substances, has actually had a positive effect also on climate," Braathen said.

Scientists warn that high levels of greenhouse gases from factories, vehicles and agriculture will lead to climate change.  Its effects include melting ice caps, rising sea levels, more extreme weather and droughts.  THE END.