Study Finds Some Biofuels Might Do More Harm Than Good
To The Environment
May 27, 2008
Biofuels based on ethanol, vegetable oil and other renewable sources are
increasingly popular with government and environmentalists as a way to
reduce fossil fuel dependence and limit greenhouse gas emissions.
But 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. The authors of a paper
published in the June issue of the journal Conservation Biology offer a
dozen policy recommendations to promote sustainability and biodiversity in
biofuel production.
The study looked at 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.
The authors argue that 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. Using a crop such as switchgrass, common
forage for cattle, would require much less energy 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."
These concerns are becoming more acute with the rapid rise of both food and
fuel prices, she said. 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.
A difficulty, Groom said, is that 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.
Also, 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 took about a year to conduct and is a synthesis of peer-reviewed
research published in a various journals. The scientists examined the
literature looking for indicators of biofuels that are more sustainable and
carry a smaller ecological footprint, then used that information to derive
the policy recommendations.
The primary audiences for the work are policy makers, students and other
biologists, Groom said. The primary 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.
SOURCE: University of Washington
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