Mysterious Stabilization of Atmospheric Methane May Buy Time in Race to Stop Global Warming
By David Biello, Scientific American, November 21, 2006
Since 1978 chemists at the University of California, Irvine, have been collecting air in 40 locations from northern Alaska to southern New Zealand. Using gas chromatography, the scientists have measured the levels of methane in the lowest layer of our atmosphere. Although not nearly as abundant as carbon dioxide methane remains the second most important greenhouse gas, both because each molecule of in the atmosphere traps 23 times as much heat as carbon dioxide and it transforms in the atmosphere into ozone, yet another greenhouse gas. During the two decades of measurements, methane underwent double-digit growth as a constituent of our atmosphere, rising from 1,520 parts per billion by volume (ppbv) in 1978 to 1,767 ppbv in 1998. But the most recent measurements have revealed that methane levels are barely rising anymore–and it is unclear why.
