A serious problem with biofuel farming today is that it competes with food production for land and other resources. In 2007, one-third of the U.S. corn crop wound up being used to produce ethanol. The resulting shortage has been fingered as a cause for the skyrocketing prices of corn products, which are staples in many countries. As the world's population and calorie needs grow, the squeeze will only get tighter.
Planting energy crops could upset the ecosystem. In Malaysia, for example, jungles are being uprooted to plant palm trees for their oil. And some promising crops could become invasive species. For example, a giant reed that seemed ideally suited for Florida's tropical climate could also overwhelm native Everglade plants and choke waterways.
Additionally, the environmental impact of producing some biofuels makes them less eco-friendly. Growing corn for ethanol uses vast amounts of water and nitrogen fertilizer. And large-scale ethanol production would mean laying new pipelines to transport the fuel -- if it were piped through existing gasoline lines, it would corrode them and pick up contaminants.
Identifying these potential problems has allowed scientists to suggest potential solutions. Rather than using potential sources of food for biofuel, farmers could raise dedicated biofuel crops that actually benefit the environment. Switchgrass, for instance, is a water-thrifty native to the Great Plains that, as a perennial, it doesn't need annual replanting. Plus, it actually restores nutrients to the soil, boosting the next season's growth.
To relieve land stress, biofuels might be extracted from plants that thrive in conditions where food crops flounder. For example, poplar trees can grow in toxic soil due to their ability to remove and destroy contaminants, such as petroleum. Another possible solution to biofuel's problems is breeding new strains of both fuel and food crops that are more drought and saltwater resistant.
Using these and other techniques to regionalize fuel markets could ease the environmental toll of transporting fuels. Cars in the Midwest might run on an ethanol blend made with Illinois corn; in the South, with Louisiana sugarcane.
Experts say we're a good five to 10 years away from seeing biofuels being used as an everyday energy source. Universities, private companies and governments alike are investing in research to speed the process. Learning where the balance lies between use and overuse, for each crop and in each region, could reap a healthy harvest of sustainable energy for generations to come.