Greenhouse gases hit record high

Greenhouse gases in the atmosphere hit a new record high in 2011, the World Meteorological Organization has said.

In its annual Greenhouse Gas Bulletin released on Tuesday, the organisation said that carbon dioxide levels reached 391 parts per million in 2011.

The report estimates that carbon dioxide accounts for 85% of the "radiative forcing" that leads to global temperature rises.

Other potent greenhouse gases such as methane also reached record highs.

The carbon dioxide levels appear to have been rising at a level of two parts per million each year for the last 10 years - with the latest measure being 40% higher than those at the start of the industrial revolution.

The WMO estimates that 375 billion tonnes of carbon have been released into the atmosphere since 1750, and that about half of that amount is still present in the atmosphere.