There's another greenhouse gases to worry about — and perhaps an opportunity for somebody who can come up with a replacement. A new study has found that sulfuryl fluoride — a fumigant used in agriculture and for killing termites in buildings — sticks around and contributes to global warming about eight times longer than previously expected. That would make it "a greenhouse gas of some importance if the quantity of its use grows as people expect," Ron Prinn, director of the Massachusetts Institute of Technology's Center for Global Climate Science, said in a Tuesday news release. Prinn co-wrote a paper on the fumigant to be published in the Journal of Geophysical Research this month as a joint project of MIT, Scripps Institution of Oceanography and other organizations. Right now the gas is in the atmosphere at concentrations of only about 1.5 parts per trillion — a miniscule amount compared to carbon dioxide's atmospheric concentration of roughly 379 parts per million in 2005, according to the Intergovernmental Panel on Climate Change (see IPCC Report Forecasts More Trouble Ahead and Can Technology Save the World?). But the fumigant's use is growing at a rate of about 5 percent a year, partly because it's being used as a replacement for ozone layer-depleting methyl bromide, the report said. Because sulfuryl fluoride is about 4,800 times more potent at trapping heat than is carbon dioxide, the fumigant could grow to be a serious global warming contributor, Prinn said — and he would like the companies that make it find other alternatives. Add the suggestion to the laundry list of steps needed to combat global warming. The International Energy Agency said in June that the world needs about $45 trillion in clean energy investments to cut carbon dioxide emission in half by 2050 (see Can You Spare $45T to Curb Global Warming?) Interestingly, another gas used in some thin-film solar cell manufacturing processes (as well as in flat-panel displays and microcircuits) has also been targeted by researchers because of its global warming potential (see Could Gas Tech Cut Solar Costs?). Nitrogen trifluoride, which is about 17,000 times more potent at trapping heat than carbon dioxide, was found to have four times the atmospheric concentration as expected, according to a study by Scripps Institute of Oceanography released in October. That's about 0.454 parts per trillion in 2008, if you want to know — an even tinier concentration than sulfuryl fluoride. (Both studies used NASA's Advanced Global Atmospheric Gases Experiment (AGAGE) network of ground-based research stations, by the way — a system that could be supplanted with satellite monitoring in the near future). Despite the low concentrations, researchers have said that both gases should be added to the list of greenhouse gases regulated by the Kyoto Protocol, or the treaty meant to supplant it that will be hashed out in a United Nations Framework Convention on Climate Change (UNFCCC) meeting in Denmark this year (see U.N. Climate Talks Pose Big Impact on Greentech) Dow Chemical Co., which developed sulfuryl fluoride in the 1950's, is also the main manufacturer of it today. Pninn called finding a substitute for the gas a "new frontier for environmental science." Whether anyone takes him up on the challenge remains to be seen.