WHEN it comes to fumigating greenhouses, we have a tricky choice: wreck the ozone layer or accelerate global warming.
Methyl bromide, the previous fumigant of choice, is being phased out because it destroys the stratospheric ozone layer that protects us from harmful solar radiation. Now it turns out that the chemical gradually replacing it, , helps to heat the atmosphere. What鈥檚 more, sulphuryl fluoride is 4780 times as potent at trapping heat as carbon dioxide, the most abundant greenhouse gas.
鈥淭he new greenhouse fumigant is 4780 times as potent at trapping heat as carbon dioxide鈥�
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The good news is that current use of sulphuryl fluoride, at around 2000 metric tonnes per year, is tiny compared with the 26 billion metric tonnes of CO2 being churned out per year.
鈥淭he concern is that emissions could increase by a factor of 10 or more as its utilisation goes global in the future,鈥� says of the Massachusetts Institute of Technology, and head of a team reporting the current status of sulphuryl fluoride in the Journal of Geophysical Research ().
Prinn says that, for now, fumigation with sulphuryl fluoride can carry on without seriously increasing global warming. He says there are surely alternatives to be found with a low impact on global warming, but warns that we must 鈥渂egin seeking them now rather than much later鈥�.