Flat-screen TVs—worse than coal plants?


Here’s an audacious claim: the production of flat-screen TVs and monitors could be worse for the climate than coal-fired power stations. From one angle, this is true. But how much should we worry?

The manufacture of some types of displays uses nitrogen trifluoride (NF3), a colorless gas that is 17,000 times as potent a driver of global warming as carbon dioxide. As sales of the displays increase each year, so does production of the gas—to about 4,000 metric tons, says the UK Independent. The question remains, however, how much of that gas is escaping the factory and seeping into the atmosphere.

While the Kyoto Protocol does not regulate the gas, given its widespread use in manufacturing, perhaps it should, which would force companies to track and report their emissions. So suggest Michael Prather and Juno Hsu, of the University of California, Irvine in a newly published paper in the journal Geophysical Research Letters. They report that this year’s production of nitrogen trifluoride, in terms of its global warming potential, is equivalent to 67 million metric tons of carbon dioxide—which, if it ends up in the atmosphere, would make it worse than the world’s largest coal-fired power plants.

The three major gases used in manufacturing semiconductors, LCDs, and photovoltaics are nitrogen trifluoride, silane, and ammonia, according to this article. NF3 can help clean up the reactors used in chemical vapor deposition, in which very thin layers of substances—silicon, carbon fiber, or really anything—are deposited on wafers. So as the market for thin-film solar technologies matures, expect an increase in the prevalence of these gases.

But the use of nitrogen trifluoride is definitely not all bad. This boutique gas was initially investigated as a promising replacement in semiconductor manufacturing for perfluorocarbons, which have a significantly worse global warming potential than nitrogen trifluoride, leading to not only an environmental upgrade but also an economic one, in the form of a 30% improvement in the etching process of microelectronics.

The very features that make this gas good for etching silicon and cleaning away unwanted deposits, however, make it rather unfriendly to human life—which is why chemistry labs have fume hoods and other apparatuses for protecting workers from exposure. So it’s quite unlikely that enormous quantities of it are escaping into the great beyond. (For more on what to do if you come face to face with this moldy-smelling, kidney-eating gas, here’s a data sheet.)

The takeaway message: perhaps nitrogen trifluoride should be monitored more carefully, with international regulations to back it up. But panic need not ensue. For more reasons not to panic, check out this sober assessment.

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