The amount of carbon dioxide in the atmosphere averaged more than 400 parts per million throughout April, the first time the planet’s monthly average has surpassed that threshold.
The data from the Scripps Institution of Oceanography at the University of California, San Diego, shows how world leaders are failing to rein in greenhouse gases that climate scientists say are warming the planet.
“We’re running out of time, but not solutions,” Ed Chen, a spokesman for the Natural Resources Defense Council, said in an e-mail. “The next big step is to limit, for the first time, carbon pollution being spewed by our power plants.”
The average value for April was measured at 401.33 ppm at the Mauna Loa monitoring station in Hawaii, according to an announcement on Twitter disclosing the finding by the institution’s Keeling Curve program. It was named for the scientist who began the measurements in 1958 and shows that temperatures are rising more quickly.
The finding adds to concerns that a buildup of carbon dioxide is damaging the atmosphere, making storms more intense, melting glaciers and putting at risk the future of seaside cities such as Miami.
The level of CO2 broke 400, as a daily average, for the first time last May. Less than a year later, the average for a month has exceeded a threshold not seen in the measured record dating back 3 million years.
Concentrations of CO2 are rising at about 2 to 3 ppm a year. The United Nations has said that in order to maximize our chances of limiting the global temperature rise since 1750 to the internationally agreed-upon target of 2 degrees Celsius (3.6 degrees Fahrenheit), the concentration of all greenhouse gases should peak at no higher than 450 ppm this century.
That includes methane and nitrous oxide, gases not included in the Scripps measurement.
The atmospheric concentration of all greenhouse gases, including including methane and nitrous oxide, was equivalent to a CO2 level of 430 ppm in 2011, according to the UN intergovernmental Panel on Climate Change. The annual average concentration of CO2 that year was about 391 ppm, according to the UN’s World Meteorological Association.