Rare greenhouse gas adds to climate concerns

Scientists are recommending that a rare but potent greenhouse gas should be included in future climate agreements after confirming that the gas is about four times more abundant than previously believed.

Nitrogen trifluoride (NF³) is commonly used to etch microcircuits in plasma-screen televisions and other flat-panel displays. As a greenhouse gas, NF³ is about 17,000 times more efficient at trapping heat than carbon dioxide, but very little was thought to escape into the atmosphere.

A team led by Ray Weiss of the Scripps Institution of Oceanography in La Jolla, California, confirmed that atmospheric concentrations have risen more than 20-fold during the past 30 years after analysing air samples from coastal stations in California and in Tasmania, Australia.

The scientists reported that in 2008 some 5,400 tonnes of NF³ were present in the atmosphere (R. F. Weiss et al. Geophys. Res. Lett. doi:10.1029/2008GL035913; 2008).