A surprising surge in carbon dioxide levels has propelled greenhouse gases to new highs in 2013, according to the annual Greenhouse Gas Bulletin released this week by the World Meteorological Organization, which collects data from over a hundred monitoring stations around the world.
“Far from falling, the concentration of carbon dioxide in the atmosphere actually increased last year at the fastest rate for nearly 30 years,” WMO’s Michel Jarraud says in a news release. At this rate, the global annual average CO2 concentration is set to cross the symbolic 400 parts per million threshold by the next year or two.
Between 1990 and 2013, there was a 34 percent increase in the warming effect on our climate due to long-lived greenhouse gases like CO2 (which accounts for 80 percent of the increase), methane, and nitrous oxide. About 40 percent of methane and 60 percent of the nitrous oxide emissions come from natural sources like wetlands and termites.
The amount of CO2 in the atmosphere in 2013 was 396.0 parts per million -- that’s 142 percent of preindustrial (around 1750) levels. Methane also reached new highs with 1824 parts per billion, up 253 percent. Nitrous oxide was 121 percent of 18th-century levels with 325.9 parts per billion.
Levels of CO2 increased more between 2012 and 2013 than any other year since 1984. The jump of 2.9 parts per million was twice as large as the average increase in recent decades. “We are seeing the growth rate rising exponentially,” WMO’s Oksana Tarasova tells Washington Post. And according to preliminary data, that’s because the steadily increasing levels were made even worse by the reduced CO2 uptake by the Earth’s biosphere, like our helpful plants and soil.
The annual report focuses on atmospheric concentrations, not emissions: Emissions are released into the atmosphere, and concentrations tell you what remains after all the interactions between the atmosphere, biosphere, and oceans have taken place. About a quarter of our total anthropogenic emissions are taken up by the oceans, and another quarter is taken up by the biosphere. This reduces the amount of CO2 in the atmosphere, but that’s also acidifying our oceans at an unprecedented rate: Oceans take up about 4 kilograms of CO2 per day per person.
“Carbon dioxide remains in the atmosphere for many hundreds of years and in the ocean for even longer. Past, present and future CO2 emissions will have a cumulative impact on both global warming and ocean acidification,” Jarraud adds. “The laws of physics are non-negotiable.” Here are some summary graphs for CO2, methane (CH4), and nitrous oxide (N2O):
Image: m01229 via Flickr CC BY 2.0 (top), World Meteorological Organization (middle)