The SUV has become the gas-guzzling poster child of American wastefulness, the villain of climate change. But there's a more insidious energy-guzzler sitting in your living room. It's your TV.

Our national love affair with television has never been stronger, what with those sexy flat-screen, high-definition models now flooding the market. Americans collectively own some 266 million working televisions, a number that's expected to grow by 3.5 percent a year. At that rate, televisions will outnumber humans in the United States by 2010. Sounds like the premise of a bad sci-fi movie, but the environmental consequences are real: Televisions currently consume about 4 percent of all residential electricity, most of which is generated by conventional coal-fired power plants spewing global warming pollution into the air.

For Noah Horowitz, an NRDC scientist whose work focuses on improving the efficiency of common energy-sucking gizmos and appliances, from vending machines to lightbulbs, slashing electricity consumption by televisions presents an interesting challenge. Big high-definition TVs consume considerably more energy than their fuzzy, outdated brethren. What's more, watching an action-packed animated film like Pixar's Monsters, Inc. requires more juice than watching Citizen Kane or some other black-and-white Hollywood classic; powering all those ultrasharp pixels adds up. And as is the case with most electronics, televisions use energy even when they're switched off.

Horowitz, whose career in science began when he was a chemical engineering student at Carnegie Mellon University, is now a bona-fide electronics geek with an environmental bent. Over the past several years, he helped write government standards for those little black power-supply units that con-vert the high-voltage AC current coming out of wall sockets into the low-voltage DC current that powers most appliances, including iPods, cell phones, and laptops. There are 1.5 billion such devices in the United States alone, and thanks to Horowitz's work, the next generation of them will use a lot less energy, preventing 3.8 million tons of global warming pollution from entering the atmosphere each year. For this, one of the nation's foremost authorities on energy efficiency, the American Council for an Energy Efficient Economy, honored Horowitz and his collaborators with its top award last year -- the Nobel Prize of the field.

Now Horowitz is looking to devise universal test methods and energy specifications for TVs, working with government agencies in the United States and abroad, as well as manufacturers in China, Japan, and Korea. The U.S. Environmental Protection Agency's current Energy Star standards consider only the relatively small amount of energy consumed during the off, or "standby," mode, based on the logic that a TV spends most of its life turned off. Surprisingly, no "active mode" testing method exists -- except one developed some 30 years ago for black-and-white models -- even though a full 85 percent of all the energy used by a television is consumed while it's on.

Realizing that this dinosaur system needed to be revamped, Horowitz, with a grant from the EPA, commissioned new research on the active-mode energy consumption of today's LCD and plasma TVs. He took these findings to the agency and major television manufacturers, and after a series of negotiations held in the United States, England, and Korea, government officials and manufacturers agreed to develop a universal test method for active-mode energy use. The end result: Manufacturers will save time and money by conducting a single product test that will be accepted by all coun-tries that sell their products.

Once the new specifications are implemented, consumers will be able to make informed, energy-conscious decisions when purchasing new televi-sions. According to Horowitz's research, a 25 percent reduction in active-mode power consumption would save Americans $1 billion on home elec-tricity bills each year while preventing 10 million tons of global warming pollution over the same time period.

That's Horowitz's genius -- finding brilliant solutions to problems nobody else even knew existed. Next up: video games.

-- Erika Brekke