GENEVA (AP) - The U.N. weather agency says concentrations of global warming gases are at record levels from emissions that exceed scientists' worst-case scenarios.
The World Meteorological Organization says heat-trapping carbon dioxide concentrations in the air have reached 389 parts per million - the highest such concentrations since the start of the industrial era in 1750.
WMO says that reflects a 20 percent increase in nitrous oxide, 39 percent rise in CO2 and 158 percent jump in methane since then.
Its report Monday cites fossil fuel-burning, loss of forests that absorb CO2 and use of fertilizer as main culprits.
The concentrations exceed the worst of seven emissions scenarios in 2001 from the U.N.'s expert climate panel.