Potent Greenhouse GasIs More Common Than Believed, Study Finds

A powerful global-warming gas is more than four times as prevalent as previously thought, a study has found. Using new analytical techniques, scientists at California’s Scripps Institution of Oceanography examined 30 years of air samples and determined that the atmosphere contains about 5,400 metric tons of nitrogen triflouride — a colorless, odorless gas that causes 17,000 times as much warming as the same mass of carbon dioxide. Previous estimates pegged the 2006 level at less than 1,200 metric tons. Although nitrogen trifluoride currently doesn’t contribute much to global warming, atmospheric levels are growing by about 11 percent a year, and it needs to be regulated along with other climate-change agents, researcher Ray Weiss said. The gas is used in etching silicon wafers and in laser production.