OAKLAND, Calif. — A greenhouse gas estimated to be 17,000 more powerful than carbon dioxide has been manufactured and used for years to make semiconductor chips, LCD flat panel displays and photovoltaic cells. Although its estimated that little of it gets emitted, its potency and long lifespan have prompted researchers to attempt to measure how much of it is in the atmosphere and call for it to be included in a future emissions reduction treaty.

Nitrogen trifluoride (NF3) was developed as an alternative to perfluorocarbon gases (which have a lifespan of 10,000-50,000 years) because less of it is emitted when used to make products. Air Products, the leading maker of the chemical, says about 2 percent of it is emitted during manufacturing.

It was not included in the Kyoto Protocol because of its limited production at the time, but in the years since, it use has spread as companies ramped up manufacturing semiconductor chips and now LCDs and photovoltaic systems.

In the report "Nf3, the greenhouse gas missing from Kyoto," University of California professors Michael Prather and Juno Hsu estimate that 4,000 tons of the chemical, which has an estimated lifespan of 550 years, will be produced this year, with double that amount being made in 2010.

Prather said that estimates of how much NF3 is emitted are not reliable enough, and is seeking to measure how much NF3 is in the atmosphere. "It's very difficult to measure, but it's measurable," he said. The chemical has become such a concern due to the widespread changeover to LCD displays, which is expected to drive up use of NF3. Last year, Air Products announced it was expanding its U.S. production and doubling its capacity in Korea to make, in total, 3,200 metric tons a year.

What Prather is hoping to find out is the exact impact of the chemical on climate change. He hopes that NF3 is included in future emissions reduction agreements so that there will be more publically available information on production figures and emissions.

Companies making and using NF3 will have to wait until complete environmental impacts are known to see if there needs to be a greener option.