WMO chief says new data shows world leaders must urgently reach a deal to limit atmospheric carbon dioxide levels
Carbon dioxide levels in the atmosphere rose from 278 parts per million in 1750 to 393 ppm by 2012
By Ed King
World leaders are running out of time to address the threat of climate change, the UN’s chief meteorologist warned as carbon dioxide levels hit record highs in April.
Data released by the World Meteorological Organization (WMO) revealed that for the first time CO2 topped 400 parts per million (ppm) in April throughout the northern hemisphere.
WMO Secretary-General Michel Jarraud said the findings had “symbolic and scientific” significance, adding it should serve as a “wake-up call” over the causes of climate change.
“If we are to preserve our planet for future generations, we need urgent action to curb new emissions of these heat trapping gases,” he said.
According to the WMO, carbon dioxide was responsible for 85% of the increase in radiative forcing – the warming effect on our climate – between 2002-2012.
The news comes a week before nearly 200 countries gather in Bonn for the latest round of UN-sponsored talks on developing a carbon dioxide emissions reduction deal.
A draft agreement is set to be presented to world leaders in November, before governments reveal what levels of carbon cuts they consider acceptable in the first quarter of 2015.
CO2 levels between March-April 2014 at WMO measuring stations (Pic: WMO)
Scientists say emissions will need to peak by 2020 and then decline rapidly to limit warming to 2C, a target agreed at the 2009 round of UN talks in Copenhagen.
According to the UN climate science panel, the world has already used between half and two-thirds of its “carbon budget” the amount of CO2 that can be released before the 2C goal is impossible.
Temperature rises above this level are likely to be increasingly dangerous they say, causing accelerated melt of ice, rising sea levels and other extreme weather events.
Global levels of carbon dioxide in the atmosphere have risen steadily in the past century, say the WMO, hitting 393.1 ppm in 2012, 141% of pre-industrial levels.
It says the amount of CO2 in the atmosphere has increased on average by 2ppm every year for the past decade.
The seasonal minimum of CO2 is in summer, when substantial uptake by plants in the northern hemisphere sucks it out of the atmosphere, and will likely see concentration levels fall below 400ppm.
But the global annual average CO2 concentration is set to cross this threshold in 2015 or 2016, says the WMO.
It takes measurements from 50 countries including stations high in the Alps, Andes and Himalayas, as well as in the Arctic, Antarctic and in the far South Pacific.