New Greenhouse Gas Threat: And You Thought Carbon Dioxide Was Bad for the Earth's Climate!

Article excerpt

What do solar panels and global warming have in common?

The answer: Both are produced with nitrogen trifluoride ([NF.sub.3]), a gas that is 17,000 times more effective than carbon dioxide at trapping atmospheric heat, according to geochemistry professor Ray Weiss and a team of researchers at the University of California--San Diego Scripps Institution of Oceanography.

Weiss and his team expect [NF.sub.3] to become a bigger problem in the near future because it is used in the manufacturing of three highly popular products: LCD televisions, computer circuits, and thin-film solar cells.

"There is a little irony in that, because thin-film solar is one of the ways we hope to reduce the fossilfuel impact," says Weiss.

Weiss's study found an [NF.sub.3] concentration of 0.02 parts per trillion in the atmosphere in 1978 and 0.454 parts per trillion in 2008. While it is now responsible for only 0.04% of human-induced global warming compared with the 60% attributable to [CO.sub.2] emissions, its share could increase exponentially. The report notes that [NF.sub.3]'s atmospheric presence is growing by 11% a year.

United Nations officials share Weiss's concerns. In 2008, the UN's Framework Convention on Climate change added [NF.sub.3] to a list of gases that the Kyoto Protocol should regulate. The Kyoto Protocol, which is due to be succeeded by a new climate treaty in 2012, currently sets no official limit on [NF.sub.3].

According to the UNFCC, manufacturers use [NF.sub.3] as a "chamber-cleaning gas" in production processes to clean unwanted buildups on microprocessor and circuit parts as they are being constructed. A gas called hexafluoroethane, which Kyoto does regulate, used to corner this market, but [NF.sub.3] became a strong competitor due to its lower costs and its absence from the Kyoto Protocol. [NF.sub.3] production has consequently increased 15%--17% a year, from 1,000 tons produced in 1992 to a projected 8,000 tons in 2010.

Most of the [NF.sub.3] is destroyed during these processes, but a remnant escapes into the atmosphere where it can linger for up to 740 years. The amount of [NF.sub.3] reaching the atmosphere varies from 2% to 16%, depending on what types of emissions-control systems the manufacturers use.

Manufacturers have many options for controlling emissions. Emissions-reduction systems on the market today can capture the escaping [NF.sub.3] for later reuse or destroy it before it can leave the facility. Manufacturers can also substitute more earth-friendly chemicals. …