GENEVA: Surging carbon dioxide levels boosted greenhouse gases in the atmosphere to a new high in 2013, amid worrying signs that absorption by land and sea is waning, the UN warned Tuesday.
"An alarm bell is ringing," Michel Jarraud, head of the World Meteorological Organization (WMO), told reporters in Geneva. In its annual report on Earth-warming greenhouse gases in the atmosphere, the UN agency said concentrations of carbon dioxide (CO2), methane and nitrous oxide all broke records in 2013. "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," Jarraud said.
"We must reverse this trend by cutting emissions of CO2 and other greenhouse gases across the board," he in a statement, and warned: "we are running out of time."
Especially worrying, Jarraud said, was the sharp rise in CO2, by far the main culprit in global warming, to 396 parts per million in the atmosphere last year. That was 142 percent of levels prior to the year 1750, and marked a hike of 2.9 parts per million between 2012 and 2013 -- the largest annual increase in 30 years. It was not clear why concentrations rose so sharply, but Jarraud suggested it could be due to a shift in the ability of oceans and the biosphere to absorb emissions.