About the Author: Sarah Goldfarb serves as DipNote's Associate Editor. Sarah will be providing information from presentations about key climate programs and scientific research at the U.S. Center at the 16th Session of the Conference of the Parties to the UN Framework Convention on Climate Change (COP-16) in Cancun, Mexico, from November 29 through December 10, 2010.
The second week at the U.S. Center at COP-16 kicked off in exciting fashion with “The Air We Breathe: It Isn't What It Used To Be." NOAA's Dr. Russ Schnell explored the relationships among fossil fuel combustion, biomass, human population, and the resulting long-term trends in dozens of greenhouse and ozone depleting gases.
At observatories in 80 countries around the world, Dr. Schnell and his team monitor the changing compositions in the atmosphere, particularly greenhouse and ozone depleting gases. From the Mauna Loa Observatory in Hawaii, atmospheric carbon dioxide has increased exponentially since 1960.
Dr. Schnell stressed that it is important to care about increasing levels of carbon dioxide, because carbon dioxide molecules act like additional feathers in a blanket, trapping more heat in the atmosphere. As you add more feathers, you are naturally going to become warmer.
How thick is the Earth's atmosphere? Relative to the size of a half meter diameter globe, around 80 percent of the mass of the atmosphere would be represented by the thickness of three to four human hairs. Did you know that about three kilos of carbon dioxide are released by the burning of each liter of fossil fuel? Moreover, about 50 percent of that stays in the atmosphere for 100 to 1,000 years.
Dr. Schnell explained some of the effects of greenhouse gases. For instance, when chlorofluorocarbons interact with ultraviolet rays, they serve as a catalyst and accelerate the process by which ozone breaks down in the atmosphere. With the Montreal Protocol in 1991, countries agreed to phase out the production of numerous substances believed to be responsible for ozone depletion, and by 1993, measurements demonstrated that ozone depleting chemicals significantly decreased.
Dr. Schnell also shared measurements from the Barrow Observatory in Alaska, where the U.S. Geological Survey measures permafrost temperatures each year. From 1989 to 2007, permafrost temperatures increased from -9.8 degrees Celsius to -6.4 degrees Celsius. Dr. Schnell said that once the permafrost begins melting, the oceans will absorb heat rather than reflecting the sun's ultraviolet rays back into space. This will change the ecosystems in the Arctic and result in a loss of habitat to species, such as polar bears and seals.
Dr. Schnell said that if we stopped burning fossil fuels, carbon dioxide would still remain in the atmosphere. However, it would begin to stabilize in about 100 years.
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