ROUND ROCK, Texas -- Computer giant Dell Inc. said this summer that it has become "carbon neutral," the latest step in its quest to be "the greenest technology company on the planet."
What that means, and what it doesn't, may surprise Dell customers and other consumers who have been bombarded with bold environmental promises from major corporations.
In the two years since Al Gore's movie, "An Inconvenient Truth," helped make climate change a marquee issue, companies from Timberland Co., the shoe maker, to News Corp., the owner of The Wall Street Journal and FoxNews.com, have promised to become "carbon neutral."
The term may suggest a company has reengineered itself so that it's no longer adding to the carbon dioxide and other greenhouse gases scientists say are contributing to climate change.
The experience of Dell, one of the few multinational corporations to claim it already has achieved carbon neutrality, shows the reality often falls short of that ideal.
The amount of emissions Dell has committed to neutralize is known in the environmental industry as the company's "carbon footprint." But there is no universally accepted standard for what a footprint should include, and so every company calculates its differently.
Dell counts the emissions produced by its boilers and company-owned cars, its buildings' electricity use, and its employees' business air travel.
In fact, that's only a small fraction of all the emissions associated with Dell. The footprint doesn't include the oil used by Dell's suppliers to make its computer parts, the diesel and jet fuel used to ship those computers around the world, or the coal-fired electricity used to run them.