Forget Al Gore and his Oscar for a global warming documentary. To gauge how today's trendy green movement is affecting computing, skip Hollywood and head to Wall Street.

There, Green Computing isn't a save-the-planet-for-our-kids movement. It's about the other green: cutting operating costs as the demand for computing power soars. It's a movement grounded in measurable, near-term results. "The top priority at hand is data center efficiency," says Sabet Elias, CTO of investment bank Lehman Brothers, which last year boosted energy efficiency 25% and set a goal of another 35% by next year.

It's not just financial services companies, with their huge processing needs, that stand to benefit from green computing. Companies in every industry, from nonprofits to consumer goods, are paying much closer attention to their power bills, as the amount spent on data center power has doubled

Elias wants to cut energy use 35% at Lehman Brothers.

in the past six years. "The CFO is getting the bills, and IT is the biggest user of energy," says Robert Rosen, CIO of the National Institute of Arthritis and Musculoskeletal and Skin Disorders. IT execs like Elias and Rosen say they're happy their conservation efforts have a social good, but they measure their progress in dollars saved.

Still, IT execs would be wise to keep an eye on more than the economics of energy-efficient computing. Energy consumption has gotten so huge--U.S. data centers consume as much power in a year as is generated by five power plants--that policy makers are taking notice and considering more regulation. A group of government and industry leaders is trying to set a clear standard for what constitutes a "green" computer, a mark that IT execs might find themselves held to. Global warming concerns could spark a public opinion swing--either a backlash against big data centers or a PR win for companies that can paint themselves green. IT vendors are piling on, making energy efficiency central to their sales pitches and touting eco-friendly policies such as "carbon-neutral computing."

One under-the-radar example of what's changing is a long acronym you'll start hearing more: EPEAT, or the Electronic Product Environmental Assessment Tool. EPEAT was created through an Institute of Electrical and Electronics Engineers council because companies and government agencies wanted to put green criteria in IT requests for proposals. EPEAT got a huge boost on Jan. 24 when President Bush signed an executive order requiring that 95% of electronic products procured by federal agencies meet EPEAT standards, as long there's a standard for that product.

The tech industry's environmental impact is gaining attention. The United Nations estimates that 20 million to 50 million tons of computer gear and cell phones worldwide are dumped into landfills each year, and it's the fastest growing segment of waste, says Greenpeace legislative director Rick Hind. At most, 12% of PCs and cell phones are recycled, he says, putting chemicals such as mercury and PVC into the environment. "The good news is that computer companies are talking about greenness, touting green programs," Hind says.

CIOs will keep setting IT strategy against their bottom lines, but they're sure to face more questions about whether there's a chance to meet environmental goals at the same time. Here's a practical guide to what's happening in Green Computing, and why IT people should care.