This is an excerpt from EERE Network News, a weekly electronic newsletter.

April 29, 2009

NOAA: Two Major Greenhouse Gases Continued to Rise in 2008

The concentration in the Earth's atmosphere of two major greenhouse gases continued to increase in 2008, according to a new report from the National Oceanic and Atmospheric Administration (NOAA). The concentration of carbon dioxide increased by 2.1 parts per million (ppm), reaching 386 ppm, suggesting an increase of 16.2 billion tons of carbon dioxide. The pre-industrial concentration of carbon dioxide was 280 ppm back in the 1800s, and many climate scientists are calling for not allowing the total concentration of greenhouse gases to exceed the equivalent of 450 ppm of carbon dioxide.

Methane concentrations also rose in 2008 for the second consecutive year, with the recent uptick following a 10-year lull. Methane concentrations increased by 4.4 parts per billion (ppb), reaching 1,788 ppb, or 1.788 ppm. That's equivalent to an additional 12.2 million tons of methane in Earth's atmosphere. As a greenhouse gas, methane is 25 times more potent than carbon dioxide. See the NOAA press release.