Concentrations in the atmosphere of the three main gases blamed for global warming all rose in 2011 to their highest since records began, the United Nations said.
Carbon dioxide, responsible for about 80 percent of the global warming effect of greenhouse gases, gained 0.51 percent to 390.9 parts per million molecules of air, the UN’s World Meteorological Organization said today in an e-mailed bulletin. The methane concentration increased 0.28 percent and the nitrous oxide level rose 0.31 percent.
Rising concentrations of the three gases in the Earth’s atmosphere threaten to render impossible the UN’s goal of containing the temperature increase to below 2 degrees Celsius of warming since industrialization, the International Energy Agency said earlier this month.
“These billions of tonnes of additional carbon dioxide in our atmosphere will remain there for centuries, causing our planet to warm further and impacting on all aspects of life on Earth,” WMO Secretary-General Michel Jarraud said in the statement. “Future emissions will only compound the situation.”
UN climate treaty envoys gather in Doha next week for two weeks of talks to extend targets under the current emissions-limiting deal, the Kyoto Protocol, and to lay the groundwork for a new pact in 2015 that will take effect from 2020.
The methane concentration in 2011 was 1,813 parts per billion molecules of air, according to the WMO bulletin. The nitrous oxide concentration was 324.2 parts per billion.