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greenhouse gas. Its residence time in the atmosphere was originally estimated at 5 years
but more recent studies suggest a lifetime of 30-40 years. Sulfuryl fluoride is 4000-5000
times more efficient that CO2 in trapping IR radiation. Currently however, the relatively
small amount (about 2000 metric tons/year) injected into the atmosphere is considered
irrelevant in the global warming discussion as CO2 is injected at a rate of 30 billion
tons/year. Figure 18.x (source: SD Union Tribune, 23 May 11; photo: Gosia Wozniacka) methyl bromide as ozone hole killer! (SD UT 052311)
not using new fumigant could cost industry $1.7 billion
However, methyl bromide is still used today after the U.S. has lobbied successfully for
critical-use exemptions from the Montreal Protocol. In 1999, an estimated 71.500 tonnes
were used annually worldwide (3). Over 75% is used by developed nations, with the U.S.
leading the usage with 43% compared to Europe with 24% as the next biggest user. Say
something about heath risks!
Methyl bromide has widely been used as soil sterilant for production of seed but also for
some crops such as strawberries (including the local strawberries in San Diego county)
and almonds(5). 18.7 Fossil Fuels and Pollution
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This document was uploaded on 11/21/2013.
- Fall '08