New research led by a biologist at the University of Washington, Bothell, shows that some of the most popular current biofuel stocks might have exactly the opposite impacts than intended.
Recent research that was led by a biologist at the University of Washington, Bothell, has shown that some of the most popular current biofuel stocks might
have exactly the opposite impacts than intended.
The authors of a paper, which is published in the June issue of the journal
Conservation Biology , have put forward a dozen policy recommendations to promote sustainability and biodiversity in biofuel production.
The study considered factors such as the energy needed to produce a renewable fuel source compared with how much energy is produced, the impact on soil fertility and effects on food supply when fuels based on crops such as corn and soybeans are mixed with fossil fuels. Based on those factors, the authors determined that corn-based ethanol is the worst alternative overall.
"It's foolish to say we should be developing a particular biofuel when that could mean that we're just replacing one problem with another," said lead author Martha Groom of the UW Bothell. Co-authors are Elizabeth Gray of The Nature Conservancy and Patricia Townsend of the UW Seattle.
Precise calculations are needed to determine the ecological footprints of large-scale cultivation of various crops used for biofuels. They note, for example, that because such large amounts of energy are required to grow corn and convert it to ethanol, the net energy gain of the resulting fuel is modest.
On the other hand when a crop such as switchgrass, is used much less energy is required to produce the fuel, and using algae would require even less.
Changing direction to biofuels based on switchgrass or algae would require significant policy changes, since the technologies to produce such fuels are not fully developed.
The paper's policy suggestions are "not definitive at all," Groom said, "but rather each category calls out a question and is a starting point in trying to find the proper answers."
The rapid rise of both food and fuel prices make these concerns even more pressing. The issue is especially touchy for farmers who might for the first time be realizing significant profits on their crops, but it also is a serious concern for motorists.
"I've heard about people getting their gas tanks siphoned, and I hadn't heard of that since the '70s," she said.
While escalating prices add pressure to find less costly fuel sources, acting too hastily could create a host of other problems. For example, farmers who plant only corn because it is suddenly profitable, and don't rotate with crops such as soybeans, are likely to greatly deplete their soil, which could limit crop growth and promote soil erosion.
Some plants are better than others for absorbing carbon dioxide from the atmosphere, while others perhaps need more cultivation, which requires more fossil fuel for farm equipment. In addition, fertilization, watering and harvesting all require energy.
The study was undertaken over one year and is a synthesis of peer-reviewed research published in a various journals. The literature was examined for indicators of biofuels that are more sustainable and carry a smaller ecological footprint, then used that information to derive the policy recommendations.
Policy makers, students and other biologists are the primary audience. The goals are to establish a logical basis to evaluate options for biofuel development and to spur new research to find the most ecologically promising alternatives.
"We don't want to make new mistakes. If we don't ask the right questions to start with, we're going to replace old problems with new ones," she said.
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Policy Recommendations
* Calculate a biofuel's ecological footprint
* Promote only biofuels that can be produced sustainably
* Select highly efficient species for biofuels
* Work to minimize land needed for biofuels
* Encourage reclamation of degraded areas
* Prohibit clearing areas for more cultivation
* Promote use of energy crops that require less fertilizer, pesticide and energy
* Promote native and perennial species
* Prohibit use of invasive species
* Promote crop rotation on cultivated lands
* Encourage soil conservation
* Promote only biofuels that are at least net carbon neutral
