More consumers are placing compact fluorescent lightbulbs (CFLs) in their shopping baskets. Using 25 percent the energy of standard incandescents (and lasting 10 times longer), the swirly little tubes have become a symbol of green living and a means to fight climate change. Australia will require homeowners and businesses to replace all incandescents with CFLs by 2010, ultimately reducing greenhouse gas emissions by four million metric tons a year. At least four U.S. states and Congress are considering similar legislation.
Yet CFLs have a downside: the bulbs contain mercury and cannot be tossed out with the ordinary trash. Roughly two billion will be sold in the U.S. this year (about 5 percent of the total lightbulb sales)—raising questions of how to handle 10 metric tons of mercury each year after the bulbs burn out.