DISCUSS: Which one's greener?

Over the past year, there has been an explosion of stories raising questions about the real environmental cost of hybrids.

One of the most misleading ones, which has been spread by countless blogs over the past several weeks, and cited without verification by several sources that appear reputable, looks to have originated in a story last November in England's Daily Mail, a right-leaning, British tabloid paper, which bore the gleefully spiteful title 'Toyota factory turns landscape to arid wilderness.' An editorial, published last month in a newspaper for a small state university on the East Coast, helped bring this misleading report a new life.

But it isn't a Toyota factory at all. The automaker has, in fact, only been purchasing significant amounts of nickel from the Sudbury , Ontario , Inco mine for its batteries in recent years, while the environmental disaster the headline is referring to largely occurred more than thirty years ago.

And that ore is at the core of a semi-urban legend that leads to dumb headlines like "HUMMER Greener than Prius," and others we've seen recently.

Toyota says that nickel has been mined from in Sudbury since the 1800s, and that "the large majority of the environmental damage from nickel mining in and around Sudbury was caused by mining practices that were abandoned decades ago." Out of the Inco mine's 174,800-ton output in 2004, Toyota purchased 1000 tons, just over a half-percent of its output. The plant's emissions of sulfur dioxide are down 90 percent from 1970 levels, and it's targeting a 97-percent reduction in those emissions by 2015, according to Toyota.

Of course, metal-hydride hybrid batteries aren't the only use for nickel. One widespread use of nickel is for the chrome (chromium-nickel) plating that's widely used in trim and wheels for luxury vehicles. And according to the Nickel Institute, which represents trade groups, manufacturers, and nickel producers, about two-thirds of all nickel mined goes toward stainless steel, which is of course widely used in vehicles - exhaust systems, for instance. Another significant portion goes toward engine alloys - pistons, rings, liners and the like; in general, the larger the engine, the more nickel it's likely to have. MORE--