Flat screens 'worse than coal'


One of the gases used in the production of LCD TVs could have a worse impact on global warming than all the developed nations' coal-fired power-stations, according to a recent report.

Companies buying flat-screen monitors and TVs are advised to ask their suppliers about the manufacturing process of the screens, if they wish to avoid greater environmental impact.

The gas in question is nitrogen trifluoride (NF3) - one tonne of which is equivalent to 17,000 tonnes of carbon dioxide in terms of its greenhouse gas effect. It is used in the production of LCDs and other semiconductors.

According to a report by Michael Prather - an atmospheric chemist and director of the Environmental Institute at the University of California, Irvine - annual production of the gas has risen to 4,000 tonnes and is likely to double by 2009 as demand for flat screens increases.

Prather's report - published in Geophysical Research Letters - claims that NF3 stays in the atmosphere for 550 years. The net effect of emissions of NF3 could have a worse impact on global warming than the CO2 emissions of coal-fired power-stations in all the developed nations put together, says Prather.

The gas was not classified in the Kyoto agreement because, at the time, it was not being produced in large enough quantities to be considered harmful. However, LCD manufacturers have switched to using it more liberally in their processes because it can be used as a replacement for hexafluoroethane and sulphur hexafluoride - two perfluorocarbons which were classified under Kyoto.

Lack of classification means companies using it will not be monitoring its emissions, argues Prather.

TMDT - a joint venture between Toshiba and Matsushita and one of the world's largest makers of LCDs - has already agreed to avoid using NF3.