According to a new report from the World Meteorological Organization, the three most significant greenhouse gases in the atmosphere all hit record levels in 2012. Carbon dioxide, methane, and nitrous oxide levels all reached new highs last year.
Last spring the Mauna Loa Observatory in Hawaii reported the first measurements of carbon dioxide levels greater than 400 parts per million. But CO2 levels are not constant throughout the atmosphere and vary during the year.
The World Meteorological Organization reports that the average carbon dioxide level for 2012 was 393 parts per million. This compares to pre-industrial levels of 278 parts per million.
Perhaps even more disturbing is that methane levels have now reached an average of more than 1,800 parts per billion. This compares to a pre-industrial average level of 700 parts per billion. In fact, methane levels have only ranged between 400 and 800 parts per billion for the last 400,000 years.
The 160% increase in methane is clearly due to human activities. Methane is tremendously more effective at trapping heat than carbon dioxide, and many scientists worry that surging methane levels could trigger rapid changes to the climate.
Many governments have pledged to keep global temperatures from rising more than 2 degrees Celsius above pre-industrial levels. In order to do so, the rapid increases in atmospheric greenhouse gases must come to an end through substantial and sustained reductions in emissions.
It won’t be easy, but the latest data say it’s getting more urgent all the time.
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Web Links
Mean Methane Levels reach 1800 ppb
http://arctic-news.blogspot.com/2013/06/mean-methane-levels-reach-1800-ppb.html
Photo, taken on July 19, 2011, courtesy of Langleyo via Flickr.
Earth Wise is a production of WAMC Northeast Public Radio. Support for Earth Wise comes from the Cary Institute of Ecosystem Studies in Millbrook, NY.