A potent greenhouse gas identified in the atmosphere: SF5CF3

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).