GENEVA, Switzerland, Sept. 9 (UPI) -- The World Meteorological Organization said Tuesday the warming effect on the climate because of greenhouse gases increased 34 percent since 1990.
"We know without any doubt that our climate is changing and our weather is becoming more extreme due to human activities such as the burning of fossil fuels," WMO Secretary-General Michel Jarraud said in a statement.
WMO published its annual Greenhouse Gas Bulletin Tuesday. It found the level of greenhouse gases in the atmosphere last year reached a new record in part because of an increase in the amount of carbon dioxide.
Carbon dioxide levels are 142 percent higher than a 1750 benchmark, a year WMO set as the start of the industrial era. For methane, emissions are 253 percent higher and nitrous oxide emissions were 121 percent more than the 1750 benchmark.
Since 1990, the WMO said radiative forcing -- the warming effect on the climate -- is up 34 percent because of the persistence of greenhouse gases in the atmosphere.
Last year, WMO said, CO2 levels in particular increased more than any other period since 1984.
"We must reverse this trend by cutting emissions of CO2 and other greenhouse gases across the board," Jarraud said. "We are running out of time."