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[SIZE="5"]Potent Greenhouse Gas Worse Than Thought[/SIZE]

Oct. 24, 2008 -- A potent greenhouse gas many thousands of times more effective at warming the world's atmosphere than carbon dioxide (CO2) is four times more prevalent than previously thought, according to a study released Thursday.

Researchers using a new NASA-funded measurement network discovered there was 4,200 metric tons of the gas nitrogen trifluoride in the atmosphere in 2006, not 1,200 tons as previously estimated for that year.

In 2008 there are 5,400 metric tons of the gas in the atmosphere, an average of an 11 percent tonnage increase per year, said Ray Weiss, head of the research team from the Scripps Institution of Oceanography in La Jolla, California.

Nitrogen trifluoride, which could not be detected in the atmosphere using previous techniques, is 17,000 times more potent as a global warming agent than a similar mass of CO2.

Emissions of nitrogen trifluoride, which is one of several gases used during the manufacture of liquid crystal flat-panel TV displays and electronic microcircuits, were previously considered so low that the gas was not thought to be a significant potential contributor to global warming.

As such the gas was not covered by the Kyoto Protocol, the 1997 agreement to reduce greenhouse gas emissions signed by 182 countries, but not by some industrialized nations including the United States.

"Accurately measuring small amounts of nitrogen trifluoride in air has proven to be a very difficult experimental problem, and we are very pleased to have succeeded in this effort," Weiss said.

The study, published in the October 31 edition of the American Geophysical Union's Geophysical Research Letters, notes that together with the gas being more potent than CO2 at trapping solar heat within the atmosphere, it also survives in the atmosphere around five times longer than CO2.

At present, however, current nitrogen trifluoride emissions contribute only around 0.15 percent of the total global warming effect caused by human-produced CO2 emissions.