Geneva - Global concentrations of greenhouse gases continued to increase in 2007, a report issued Tuesday said, with carbon dioxide rates reaching the highest level ever recorded.

The major cause of the gas emissions was human activities like burning fossil fuels and agriculture, the World Meteorological Organization (WMO) reported, adding that methane gas emissions had their greatest increase since 1998.

"Carbon dioxide is responsible for 90 per cent of the increase in the greenhouse effect" in the past five years, said Geir Braathen, a senior researcher with the WMO. The gas's concentration rose 5 per cent over the previous year.

Greenhouse gases "trap radiation within the Earth's atmosphere and cause it to warm," with a greater warming impact in 2007 than the year before.

However, the Montreal Protocol on ozone depletion from 1987 "has had a positive affect on the climate, and reduced greenhouse gas warming," Braathen said.

This almost accidental impact was five times greater than the reduction target set for 2012 by environmental Kyoto Protocol.

The Greenhouse Gas Bulletin, published by the UN affiliated organization, has reported on the state of the atmosphere since 2005 using information gathered in 65 countries. (dpa)