A new research has found that 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.
The research, by University of California Irvine (UCI) researchers, discovered that Sulfuryl fluoride 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.
According to study authors Mads Sulbaek Andersen, Donald Blake and Nobel Laureate F. Sherwood Rowland, sulfuryl fluoride exists for decades, and evidence indicates that its levels have nearly doubled in the last six years.
"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," he added.
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 blocks," said Blake.
"If we put something with this blocking effect in that area, then we're in trouble - and we are putting something in there," he added.
The chemists worry that emissions will increase as new uses are found for sulfuryl fluoride - especially given the ban of methyl bromide, an ozone-depleting pesticide regulated under the Montreal Protocol.
Sulfuryl fluoride emissions are not regulated, though officials do consider it a toxic contaminant.
The insecticide is pumped into a tent that covers a termite-infested structure. When the tent is removed, the compound escapes into the atmosphere.
According to the researchers, a suitable replacement should be found, one with less global warming potential.