Time running out, says UN, as carbon dioxide levels hit new high

In April, for the first time, the mean monthly CO2 concentration in the atmosphere topped 400 ppm throughout the northern hemisphere


This was the first time the monthly mean concentration of CO2 in the atmosphere exceeded the 400 ppm threshold. Photo: AP
This was the first time the monthly mean concentration of CO2 in the atmosphere exceeded the 400 ppm threshold. Photo: AP

New Delhi: The World Meteorological Organization (WMO) on Monday said that concentrations of carbon dioxide in the atmosphere crossed all thresholds in the northern hemisphere for the month of April. WMO is the weather arm of the United Nations.

WMO’s monitoring stations in the northern hemisphere reported record atmospheric CO2 concentrations.

“For the first time, monthly concentrations of carbon dioxide (CO2) in the atmosphere topped 400 parts per million (ppm) in April throughout the northern hemisphere,” a press statement issued by WMO said. It added that the crossing of this threshold is of symbolic and scientific significance and reinforces evidence that the burning of fossil fuels and other human activities are responsible for the continuing increase in heat-trapping greenhouse gases warming the planet.

WMO secretary-general Michel Jarraud said that this should serve as yet another wakeup call about the constantly rising levels of greenhouse gases driving 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 in a press statement. “Time is running out,” he added.

Carbon dioxide remains in the atmosphere for hundreds of years and its lifespan in the oceans is even longer. It is the single most important greenhouse gas emitted by human activities. CO2 was responsible for 85% of the increase in radiative forcing—the warming effect on the climate—over the decade 2002-2012, according to WMO.

WMO’s Greenhouse Gas Bulletin dated November 2013 says, the amount of CO2 in the atmosphere reached 393.1 ppm in 2012—141% higher than the pre-industrial level of 278 ppm. The amount of CO2 in the atmosphere has increased on average by 2 ppm per year for the past 10 years.

The global community is aspiring to limit CO2 emissions to a level that is double the pre-industrial emissions level, said Prodipto Ghosh, distinguished fellow at the think tank The Energy and Resources Institute (Teri). “The world is looking to contain the temperature rise within two degree celsius,” Ghosh added.

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