Still, experts almost unanimously see corn-based ethanol as the beta version of biofuel—an early phase of alternative fuel use that, while necessary, must be improved before realizing success. For starters, making biofuel from corn isn't entirely eco-friendly. Because corn is an annual crop—meaning its life cycle is a single season—farming it can release nitrous oxide, a greenhouse gas more potent than carbon dioxide, Dale's research has shown.
Done correctly, though, corn can be grown in a way that won't release a damaging amount of nitrous oxide. The bigger problem with corn has to do with meeting the presidential benchmarks: it takes a lot of energy to produce fuel from the grain of corn. A prohibitive amount, some feel. "We can't make enough ethanol from corn to change our liquid fuel dependence," says Dale. If you were to add up all the energy it takes to create a bushel of corn—from making the farm machinery to tilling the land—you get only about 1.3 times more energy out of the resulting biofuel, says Somerville. A good energy return would be around 10 times that figure.
However flawed, corn-based biofuel's initial promise—it has resurrected the country's agricultural industry—might have paved the way for a more efficient alternative to enter the market. Experts call this next-generation fuel "cellulosic ethanol." The term is intimidating, but the idea is relatively simple: biofuel producers can convert more sugar into energy if they use the whole plant instead of simply the grain.
In addition to diminishing reliance on petroleum, cellulosic ethanol will neutralize more greenhouse gases than corn. "There's a limit on corn-based biofuel," says energy and environmental scholar David Sandalow of the Brookings Institution in Washington. "But if we can break through technical barriers on cellulosic forces, then the potential is much, much higher."
Overcoming these technical barriers won't require a miracle, just a few research advances and lots of money. In the meantime, scientists and producers continue searching for plants that naturally yield more energy than crops like corn and soybeans do. Most of this focus has been on perennial crops such as switchgrass. Because perennials last several seasons, they don't allow nitrous oxide to escape from the soil into the atmosphere; they are both carbon and nitrous neutral. More importantly, the energy return on these crops is some 15 to 20 times what's used to produce them. The star of this group is Miscanthus giganteus, a wild plant native to tropical regions in Africa and Asia. In addition to its high energy output, Miscanthus requires less water than typical crops and stores more carbon in the soil, says Somerville. The trick for biofuel developers will be domesticating this species and sustaining it over long periods of time.
"I think the industry's going to happen more quickly than most people realize," says Dale. "Once we recognize that we can make ethanol from grass grown to purpose, for something in the neighborhood of $1.50 or $1.20 a gallon, then it's going to explode." This recognition might happen more quickly than even Dale would have imagined. Just five days after his meeting with Bush, the Department of Energy announced that over the next several years it will invest nearly $400 million in six cellulosic ethanol plants across the country.
A Bumpy Road
The technological wheels that will carry us into this post-oil world are in full motion, and no brakemen need apply. Farmers, however, might want to have their resumes handy. More biofuel production first requires more plant and crop biomass, and the agricultural industry is in the midst of such a spike. On March 30, the day Horgan and her crew split for the south, the Department of Agriculture predicted that farmers would grow more than 90 million acres of corn in 2007—the highest total since World War II.
The amount of jobs and money funneling into the American Midwest could be an economic boon, the ripple effects of which might be felt by every taxpayer, says Somerville. "We've gone from a couple to 150 corn-grain ethanol plants in 3 years," he says. He describes the tale of one farmer and his neighbor, who raised $50 million for such a plant in nine hours. "There's a fascinating re-adjustment of the agricultural economy going on right now." This agricultural renaissance could diminish the government subsidies that have supported the industry since the Depression.
Some critics have wondered whether enough land exists for this growing crop load, though most experts dismiss this concern, particularly once plants like Miscanthus gain wider use. (The crop is so efficient at harnessing energy, writes Somerville in a recent issue of Current Biology, that, in the right conditions, covering about 3 percent of the world's surface with it could satisfy all human energy needs.) If and when Miscanthus and other high-yield crops displace corn, farmers should have no problem switching to energy crops, Somerville says. "I personally think this is good socially."
For Iowa farmers, that might be true. But abroad, Miscanthus, switchgrass and similar plants might create as many problems as they solve, says Daniel Kammen of the University of California, Berkeley, which in February received a $500 million grant from British Petroleum to open an alternative fuel research facility, the Energy Biosciences Institute. Kammen, already director of Berkeley's Renewable and Appropriate Energy Lab, will direct the social impact side of biofuels when the new institute begins operation this summer. Crops like Miscanthus aren't edible, so if farmers—particularly those in poor countries—find themselves without a biofuel buyer they can't go and sell the plants to food suppliers, Kammen says. Unless those directing the biofuel market require certain amount of crops that are less efficient energy resources but can also be sold as food, we could see a repeat of the green revolution of the 1960s. At that time, an increase in food production drove up the cost of things like irrigation and fertilizer so much that rich farmers prospered at the expense of the poor.