Watching flat-screen TV declared environmentally hazardous

The sales of more and more flat-screen televisions could have a wider impact on global warming than the world's largest coal-fired power stations, says a leading environmental scientist. That is because a gas used in the making of flat screen televisions, nitrogen trifluoride (NF3), is accelerating global warming and damaging the atmosphere as its production has gone up to around 4,000 tonnes.

Michael Prather, director of the environmental institute at the University of California at Irvine says that as a driver of global warming, nitrogen trifluoride is 17,000 times more potent than carbon dioxide. Still, there are no account of exactly how much of it is being pumped into the atmosphere by industry. His research shows that production of the gas is ''exploding'', and is expected to double by next year.

NF3 remains in the atmosphere for 550 years, says Prather, and unlike common greenhouse gases like carbon dioxide, sulphur hexafluoride (SF6) and perfluorocarbons (PFCs), the Koyoto protocol or any other agreement on the global environment seems to have missed regulating emissions of the gas. Prather says the fact that the emissions of the gas are not controlled in the same way as other greenhouse gases could see companies be relatively careless with it, as there are no punitive actions associated with its emission.

In his report in the journal Geophysical Research Letters, Prather and co-writer Juno Hsu say that the current year's production of NF3 will be equivalent to 67 million tonnes of carbon dioxide, translating into an impact larger than ''that of the industrialised nations' emissions of PFCs or SF6, or even that of the world's largest coal-fired power plants". That is almost the equivalent of the global-warming emissions from Austria.

Environmental concerns over NF3 have led Toshiba Matsushita Display Technology to avoid use of the gas altogether. NF3 is usually used in chemical vapour deposition that makes liquid crystal displays, semiconductors, and synthetic diamond.

NF3 is not covered by the Kyoto protocol since it was only produced in relatively minuscule quantities when the treaty was signed in 1997.

This year, around 50 per cent of televisions sold across the globe are estimated to be either plasma, or LCD-based flat-screen televisions, and around 80 million analog television sets are expected to be discarded by Americans alone by the end of 2009. The global scenario would peg the numbers much higher. The irony is that LCD televisions are often marketed as eco-friendly, as they consume less power than plasma and older rear-projection televisions.