A Potent Greenhouse Gas Identified in the Atmosphere: SF5CF3
W. T. Sturges,1
T. J. Wallington,2
M. D. Hurley,2
K.
P. Shine,3
K. Sihra,3
A. Engel,4
D. E. Oram,1
S. A. Penkett,1
R. Mulvaney,5
C. A. M. Brenninkmeijer6
We detected a compound previously unreported in the
atmosphere, trifluoromethyl sulfur pentafluoride
(SF5CF3). Measurements of its infrared
absorption cross section show SF5CF3 to have a radiative forcing of 0.57 watt per square meter per parts per billion.
This is the largest radiative forcing, on a per molecule basis, of any
gas found in the atmosphere to date. Antarctic firn measurements show
it to have grown from near zero in the late 1960s to about 0.12 part
per trillion in 1999. It is presently growing by about 0.008 part per
trillion per year, or 6% per year. Stratospheric profiles of
SF5CF3 suggest that it is long-lived in the
atmosphere (on the order of 1000 years).
1 School of Environmental Sciences, University
of East Anglia, Norwich NR4 7TJ, UK.
2 Ford Motor
Company, Mail Drop SRL-3083, Dearborn, MI 48121-2053, USA.
3 Department of Meteorology, University of Reading,
Reading RG6 6BB, UK.
4 Institute for Meteorology and
Geophysics, Johann Wolfgang Goethe University of Frankfurt, D-60325
Frankfurt, Germany.
5 British Antarctic Survey,
Natural Environment Research Council, Cambridge CB3 0ET, UK.
6 Atmospheric Chemistry Division, Max Planck
Institute for Chemistry, D-55060 Mainz, Germany.
