Bye-bye, incandescent bulb?

Is Thomas Edison's most famous invention, the incandescent light bulb, about to fizzle into obscurity?

Thanks to global warming, the ban-the-bulb movement is gaining strength. Australian officials and European lighting manufacturers have announced phaseouts of the energy-draining bulb. A California legislator has proposed a ban. Now, in a move that could speed the move away from the 128-year-old invention, some of the world's largest bulbmakers have joined environmental groups and the California Energy Commission in talks that could lead to a phaseout in the US within a decade, sources say.

The scope of the move – and manufacturers' support of it – is still undecided, they add. "We're talking about a 10-year phaseout of incandescents, but there's no plan on paper on how to do that yet," says a source close to the talks who, lacking authorization to speak to media, asked not to be identified. "We're thinking through and seeking answers to a number of questions," said the source, noting the talks could yet fail.

The negotiations – which could yield a phaseout of incandescents for the huge California market, or perhaps affect the product line in most of the nation – are taking place amid evidence of a rising anti-incandescent clamor.

• On Monday in Paris, the European Lamp Companies Federation, a trade group of lighting manufacturers in the European Union, unveiled a pact to phase out incandescent bulbs, without specifying a deadline.

• Last week, Australians officials announced a phaseout of incandescents bulbs by 2009.

• In California, state lawmaker Lloyd Levine in January introduced a bill that would ban the sale of incandescent bulbs statewide by 2012.

"We are definitely seeing a trend with some leaders in the lighting industry proposing a ... shift away from incandescent to higher-efficiency technologies," says William Prindle of the American Council for an Energy-Efficient Economy.

If the move to dim the ubiquitous incandescent bulb is sweeping enough, it could represent a coup for efforts to curb climate change via greater energy efficiency, he and other experts say.

"Lighting is ... one of the areas where we can achieve significant energy gains," says Claudia Chandler of the California Energy Commission. "We expect incandescent to yield to other technologies as energy-efficiency standards get tougher."

The incandescent bulb is an energy hog. Just 5 percent of the electricity it uses goes to light the bulb; the other 95 percent is heat. Improving light output and lowering heat output would reduce demand for electricity from coal-fired power plants, which emit carbon dioxide. CO2, most climate scientists say, is the single largest contributor to global warming.

Incandescent bulbs are burning in most of the 3 billion to 4 billion screw-in sockets in US homes and businesses – swallowing about 10 percent of all US electricity use, the US Department of Energy reports. Retail giant Wal-Mart has said it wants to sell 100 million compact fluorescent bulbs (CFLs) by 2008.

If all homes and businesses used bulbs that are 35 to 75 percent more efficient – such as CFLs and advanced halogen lamps – they would collectively save almost $10 billion a year in energy bills. The switch would also cut energy demand enough to eliminate the need to build dozens of coal-fired power plants, says the Natural Resources Defense Council, an environmental group. That would prevent tens of millions of tons of carbon-dioxide emissions every year for decades, and would help stabilize the climate, says NRDC.

"We should no longer be selling the least-efficient light bulb," says Noah Horowitz, a NRDC senior scientist. "We have the technology today."

But the venerable incandescent may have life in it yet. General Electric Co. said Friday that by 2010 it would make an incandescent bulb twice as efficient as today's – and by 2012 produce one that is four times more efficient, on par with CFLs.

"Banning any specific technology is absolutely unnecessary," says Kim Freeman, a spokeswoman for GE's Consumer & Industrial division in Louisville, Ky., which includes lighting. "GE supports national policy that will drive improved energy standards for all lighting products, regardless of the technologies."

All incandescent-bulb makers reportedly remain wary of proposed bans, as well as of any marketing misstep that might alienate customers. Like NRDC's Mr. Horowitz, GE officials say they want tougher performance standards for all technologies – not a ban on one technology.

Among three large lighting manufacturers said to be involved in the talks, Philips Electronics North America Corp. is the most enthusiastic, says a source near the phaseout discussions. Osram Sylvania, in Danvers, Mass., seems to be warming to the idea. It's not clear if General Electric, America's largest lighting manufacturer, likes or dislikes the idea, the source says.

All three firms declined to comment on any phase-out discussions. But some say they favor, in principle, a worldwide shift from incandescent bulbs. "We at Philips do support the idea of phasing out incandescent lights over a reasonable period of time, roughly 10 years around the globe," says Randall Moorhead, a vice president for Philips Electronics, the US subsidiary of Royal Philips Electronics in Amsterdam.

Any move in California toward tougher energy standards for lighting are expected to raise the bar for federal lighting-efficiency standards now under review.

A potential drawback is that CFLs contain mercury – about 5 milligrams per bulb, says GE. Incandescents don't. In recognition that CFL disposal could pose a problem, major manufacturers are promoting bulb-recycling programs and plan to cut bulbs' mercury content. Even so, California Energy Commission studies show that a shift to CFLs would yield a net decrease in mercury, because fewer power plants would mean less mercury would be emitted from plants, Ms. Chandler says.