Irvine, Calif., Jan. 21, 2009 An insecticide used to fumigate termite-infested buildings is a strong greenhouse gas that lives in the atmosphere nearly 10 times longer than previously thought, UC Irvine research has found.
Sulfuryl fluoride, UCI chemists discovered, stays in the atmosphere at least 30-40 years and perhaps as long as 100 years. Prior studies estimated its atmospheric lifetime at as low as five years, grossly underestimating the global warming potential.
The fact that sulfuryl fluoride exists for decades coupled with evidence that levels have nearly doubled in the last six years concerns study authors Mads Sulbaek Andersen, Donald Blake and Nobel Laureate F. Sherwood Rowland, who discovered that chlorofluorocarbons in aerosol cans and other products damage the ozone layer. That finding led to a worldwide ban on CFCs.
"Sulfuryl fluoride has a long enough lifetime in the atmosphere that we cannot just close our eyes," said Sulbaek Andersen, a postdoctoral researcher in the Rowland-Blake laboratory and lead author of the study. "The level in the atmosphere is rising fast, and it doesn't seem to disappear very quickly."
This study will appear online Jan. 21 in the journal Environmental Science and Technology.
Kilogram for kilogram, sulfuryl fluoride is about 4,000 times more efficient than carbon dioxide at trapping heat, though much less of it exists in the atmosphere.
Its climate impact in California each year equals that of carbon dioxide emitted from about 1 million vehicles. About 60 percent of the world's sulfuryl fluoride use occurs in California.
Sulfuryl fluoride blocks a wavelength of heat that otherwise could easily escape the Earth, the scientists said. Carbon dioxide blocks a different wavelength, trapping heat near the surface.
"The only place where the planet is able to emit heat that escapes the atmosphere is in the region that sulfuryl fluoride blo
|Contact: Jennifer Fitzenberger|
University of California - Irvine