25.9 Despite ongoing controversies and setbacks, the future of biofuels looks bright.
Working with Nature Conservancy scientist Joseph Fargione, Tilman and Hill set about to determine exactly how much CO2 is released by clearing land for crop biofuels, which involves burning vegetation and plowing carbon-rich soil. The results were shocking: the team found it could take decades—or even centuries—of biofuel production to make up for the amount of CO2 released during land conversion, what they called the carbon debt. For instance, it will take 93 years to make up for the carbon debt resulting from digging up central grasslands in the United States to produce corn ethanol. To repay the carbon debt for clearing peatland rainforest for palm biodiesel in Indonesia and Malaysia: 423 years. The only biofuel with zero carbon debt? Bioethanol from prairie biomass grown on marginal cropland, making this crop a strong choice in many Canadian regions.
The results solidified Tilman’s hopes for a new type of biofuel that circumvents the problems of corn ethanol, such as fuel from switchgrass or algae. “Biofuels, if used properly, can help us balance our need for food, energy, and a habitable and sustainable environment,” Tilman wrote in a 2007 opinion piece in the Washington Post. “We have the knowledge and the technology to start solving these problems.”
Select references in this chapter:
Fargione, J., et al. 2008. Science, 319: 1235–1238.
Russelle, M.P., et al. 2007. Science, 316: 1567b.
Tilman, D., et al. 2006. Nature, 441: 629–632.
Tilman, D., et al. 2006. Science, 314: 1598–1600.
Tilman, D., et al. 2007. Science, 316: 1567c.
BRING IT HOME: PERSONAL CHOICES THAT HELP
Biofuels represent a potential replacement for fossil fuels and might be an especially important fuel for transportation. Despite the promise of biofuel use, there are also trade-offs such as the fossil fuel inputs needed to grow fuel crops. Developing new biofuel technologies may help us meet the energy needs of the future.
Individual Steps
Visit ecogeek.org to find information on experiments and new advances in biofuel technology.
Review Infographic 25.7 and take steps to make your vehicle and driving more fuel efficient; make the investment in a hybrid or electric vehicle if you can.
Group Action
Host a movie night to watch FUEL, an award-winning film that looks at the history of biofuels as well as possible solutions for the future.
Join a biofuel co-op in your area that provides alternatives to power your vehicle.
Policy Change
Use the Office of Energy Efficiency site (http://oee.nrcan.gc.ca/transportation/alternative-fuels/780) to learn about sustainable biofuel options and stay current on biofuel programs.
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