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The use of methyl bromide was ended in 2005 because it was helping to deplete the ozone layer up there in the upper atmosphere of Earth.
It was phased out by order of the international treaty called the Montreal Protocol (on Substances That Deplete the Ozone Layer). The Montreal Protocol was enacted to limit chlorofluorocarbons and other greenhouse gases (from eroding our quality of life) and to protect the ozone layer.
Well, surfuryl fluoride replaced methyl bromide because, at the time, it was thought that is was safe to use. Both are standard fumigant used to control insects in and around grain storage facilities and to eliminate insects that feed directly on crops.
U.S. atmospheric scientist Ron Prinn, of Massachusetts Institute of Technology (MIT), one of the authors of the study that made this discovery, stated, “Such fumigants are very important for controlling pests in the agricultural and building sectors.” However, he added that "industry had to find alternatives” when mehyl bromide was phased out, “so sulfuryl fluoride has evolved to fill the role.” [MIT News: “New greenhouse gas identified: Early detection may permit 'nipping it in the bud'”]
Scientists performing a research study, from Scripps Institution of Oceanography, Massachusetts Institute of Technology, CSIRO Marine and Atmospheric Research, and other institutions, on the effects of surfuryl fluoride have found that the gas is not as safe as we thought it was to our health and the health of our atmosphere above us.
Their paper, which highlights their conclusions, is entitled “Sulfuryl fluoride in the global atmosphere.” It was published on Thursday, March 12, 2009, in the Journal of Geophysical Research [J. Geophys. Res., 114, D05306, doi:10.1029/2008JD011162].
Page two continues.
It authors are: J. Mühle, R. F. Weiss, B. R. Miller, P. K. Salameh, C. M. Harth (all from the Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California, U.S.A.); Jens Huang and Ron G. Prinn (Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, U.S.A.); P. J. Fraser (Centre for Australian Weather and Climate Research, CSIRO Marine and Atmospheric Research, Aspendale, Victoria, Australia), L. W. Porter (Bureau of Meteorology, Melbourne, Victoria, Australia); and B. R. Greally, S. O'Doherty, and P. G. Simmonds (School of Chemistry, University of Bristol, Bristol, U.K.)
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The authors state in the abstract to their paper, “The first calibrated high-frequency, high-precision, in situ atmospheric and archived air measurements of the fumigant sulfuryl fluoride (SO2F2) have been made as part of the Advanced Global Atmospheric Gas Experiment (AGAGE) program.”
AGAGE is a NASA-sponsored global research program. Dr. Prinn, stated, "In AGAGE, we don't just monitor the big greenhouse gases that everybody's heard of. This program is also designed to sniff out potential greenhouse and ozone-depleting gases before the industry gets very big." [MIT News]
They found that the concentration of sulfuryl fluoride in the troposphere increased by about 5% per year from 1978 to 1999.
They stated in their abstract, “The global tropospheric background concentration of SO2F2 has increased by 5 ± 1% per year from 0.3 ppt (parts per trillion, dry air mol fraction) in 1978 to 1.35 ppt in May 2007 in the Southern Hemisphere, and from 1.08 ppt in 1999 to 1.53 ppt in May 2007 in the Northern Hemisphere.”
They added, “The SO2F2 interhemispheric concentration ratio was 1.13 ± 0.02 from 1999 to 2007.”
Dr. Prinn also stated, “Our analysis has shown that the lifetime is about 36 years, or eight times greater than previously thought, with the ocean being its dominant sink.” [MIT News]
Page three concludes.
Although the concentration of the sulfuryl fluoride gas in our atmosphere is not of great concern at the moment, the authors warn that its increased concentration in the future is indeed a potential problem.
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The authors conclude, “With mean SO2F2 tropospheric mixing ratios of 1.4 ppt, its radiative forcing is small and it is probably an insignificant sulfur source to the stratosphere. However, with a high global warming potential similar to CFC-11, and likely increases in its future use, continued atmospheric monitoring of SO2F2 is warranted.”
U.S. chemist Jens Mühle, another author of the study, stated, "Unfortunately, it turns out that sulfuryl fluoride is a greenhouse gas with a longer lifetime than previously assumed. This has to be taken into account before large amounts are emitted into the atmosphere."
Prinn concludes, within the MIT News article, that, "... fumigation is a big industry, and it's absolutely needed to preserve our buildings and food supply."
The article adds, “But identifying the greenhouse risks from this particular compound, before many factories have been built to produce it in very large amounts, would give the industry a chance to find other substitutes at a time when that's still a relatively easy change to implement."
Dr. Prinn comments, "Given human inventiveness, there are surely other alternatives out there.”
And, he also states that the world should in this case, and in all cases that are potential problems to our climate and human health, “… try to head off potential dangers as early as possible, rather than wait until it's a mature industry with lots of capital and jobs at stake."
So, we know there is a problem out there with sulfuryl fluoride. Will we do something about it now, rather than later--when its concentration is much higher?
Will we?
