WASHINGTON (Reuters) - Levels of a powerful greenhouse gas are four times as high as previously thought, according to new measurements released on Thursday.

New analytical techniques show that about 5,400 metric tons of nitrogen trifluoride are in the atmosphere, with amounts increasing by about 11 percent per year.

Ray Weiss of the Scripps Institution of Oceanography in La Jolla, California, and colleagues said it had not been possible to accurately measure this gas before.

They said nitrogen trifluoride is 17,000 times more effective at warming the atmosphere than an equal mass of carbon dioxide, although it does not yet contribute much to global warming.

Previous estimates had put levels of the gas at less than 1,200 metric tons in 2006.

Nitrogen trifluoride, a colorless, odorless, nonflammable gas, is used to etch silicon wafers and in some lasers.

Writing in Geophysical Research Letters, Weiss and colleagues said they analyzed air samples gathered over the past 30 years under the NASA-funded Advanced Global Atmospheric Gases Experiment.

Weiss said nitrogen trifluoride needs to be regulated, as carbon dioxide is.

"From a climate perspective, there is a need to add nitrogen trifluoride to the suite of greenhouse gases whose production is inventoried and whose emissions are regulated under the Kyoto Protocol, thus providing meaningful incentives for its wise use," he said.

Michael Prather, an atmospheric chemist at the University of California at Irvine, noted nitrogen trifluoride is being used more commonly and predicted that more would be found in the atmosphere.

"It is now shown to be an important greenhouse gas," Prather, who was not involved with the Scripps study, said in a statement. "Now we need to get hard numbers on how much is flowing through the system, from production to disposal."

(Reporting by Maggie Fox, editing by Philip Barbara)

جشنواره بين المللی فيلم توکيو روز شنبه با موضوع محوری محيط زيست و با حضور فيلم سازان مختلف از سرتاسر جهان و دوستداران سينمای ژاپن در پايتخت اين کشور جریان دارد.

به گزارش خبرگزاری ها، در مراسم افتتاحيه اين جشنواره، به جای فرش قرمز، فرش سبز رنگی پهن شده بود.

اين اقدام به گفته مسئولان جشنواره بين المللی فيلم توکيو، به نشانه احترام به محيط زيست انجام گرفته بود.
اين فرش از بازيافت بطری های پلاستيکی ساخته شده بود.

ستارگان فيلم افتتاحيه فستيوال به نام « صخره قرمز» از جمله « جان وو» کارگردان فيلم و « تونی لونگ» بازيگر آن، در مراسم افتتاحيه حضورداشتند.

همچنين « جولين مور» ستاره هاليوودی فيلم « کوری»، همراه با « يوشينو کيمورا»، ديگر بازيگر ژاپنی فيلم، در ميان ستارگانی بودند که بر روی فرش سبز جشنواره قدم گذاشتند. « تارو آسو»، نخست وزير ژاپن، نيز هنرمندان را بر روی اين فرش همراهی می کرد.