Money doesn’t grow on trees, so it should stand to reason that diesel fuel wouldn’t grow on trees either. And yet the Brazilian Copaifera langsdorfii tree has been quietly producing a natural diesel variant in the tropical rainforest, something we’ve known about since the seventeenth century. It’s only now that farmers in Australia have decided to farm the tree on a large scale in the hopes of having 20,000 living, above-ground fuel wells.

With oil prices recently breaking the psychologically important barrier of $100 per barrel, commuters aren't the only ones feeling the heat. Cargo vessels are responsible for moving 98% of all intercontinental goods, and a transatlantic crossing on fully-loaded 200-meter ship is not light on the diesel consumption. So far, at least two companies promise to deliver a technology not seen on massive ocean-going ships in quite some time: the sail.

"Cellulosic ethanol technology is a lot closer to reality than a lot of articles would have you think," said Jacques Beaudry-Losique, manager of the Department of Energy's Biomass Program this morning at the American Association for the Advancement of Science meeting. After some well-publicized studies stated that corn-based biofuels might exacerbate CO2 damage to the environment, focus has shifted to these so-called "second generation" biofuels that use non-food crops such as switchgrass, wood chips or crop residues (e.g. all the parts of the corn plant that are currently wasted after harvest--the stalk, leaves and "cob").

For a closer look at the Honda FCX, click 'View Photo Gallery.' And for a rare Q&A with Honda's president and CEO, continue reading on the second page.

Over the past several decades, the promise of the "car of tomorrow" has remained unfulfilled, while the problems it was supposed to solve have only intensified. The average price of a gallon of gas is higher than at any time since the early 1980s. The Middle East seems more volatile than ever. And even climate skeptics are starting to admit that the carbon we´re pumping into the atmosphere might have disastrous consequences. To these circumstances, automakers have responded with a fleet of cars that averages 21 miles per gallon, about four miles per gallon worse than the Model T.

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With all the buzz about hybrids, it’s easy to ignore our homegrown alternative fuel: ethanol. Clean-burning and infinitely renewable—we’re talking grain alcohol—ethanol is dear to environmentalists and economists alike. The standard 85/15-percent ethanol/gasoline blend (E85) is widely used in Sweden, but there are only 313 E85 fueling stations in the U.S.