February 8, 2008
By ELISABETH ROSENTHAL
Almost all biofuels used today cause more greenhouse gas emissions than
conventional fuels if the full emissions costs of producing these
"green" fuels are taken into account, two studies being published
Thursday have concluded.
The benefits of biofuels have come under increasing attack in recent
months, as scientists took a closer look at the global environmental
cost of their production. These latest studies, published in the
prestigious journal Science, are likely to add to the controversy.
These studies for the first time take a detailed, comprehensive look at
the emissions effects of the huge amount of natural land that is being
converted to cropland globally to support biofuels development.
The destruction of natural ecosystems --- whether rain forest in the
tropics or grasslands in South America --- not only releases greenhouse
gases into the atmosphere when they are burned and plowed, but also
deprives the planet of natural sponges to absorb carbon emissions.
Cropland also absorbs far less carbon than the rain forests or even
scrubland that it replaces.
Together the two studies offer sweeping conclusions: It does not matter
if it is rain forest or scrubland that is cleared, the greenhouse gas
contribution is significant. More important, they discovered that, taken
globally, the production of almost all biofuels resulted, directly or
indirectly, intentionally or not, in new lands being cleared, either for
food or fuel.
"When you take this into account, most of the biofuel that people are
using or planning to use would probably increase greenhouse gasses
substantially," said Timothy Searchinger, lead author of one of the
studies and a researcher in environment and economics at Princeton
University. "Previously there's been an accounting error: land use
change has been left out of prior analysis."
These plant-based fuels were originally billed as better than fossil
fuels because the carbon released when they were burned was balanced by
the carbon absorbed when the plants grew. But even that equation proved
overly simplistic because the process of turning plants into fuels
causes its own emissions --- for refining and transport, for example.
The clearance of grassland releases 93 times the amount of greenhouse
gas that would be saved by the fuel made annually on that land, said
Joseph Fargione, lead author of the second paper, and a scientist at the
"So for the next 93 years you're making climate change
worse, just at the time when we need to be bringing down carbon emissions."
The Intergovernment Panel on Climate Change has said that the world has
to reverse the increase of greenhouse gas emissions by 2020 to avert
disastrous environment consequences.
In the wake of the new studies, a group of 10 of the United States's
most eminent ecologists and environmental biologists today sent a letter
to President Bush and the speaker of the House, Nancy Pelosi
urging a reform of biofuels policies. "We write to call your attention
to recent research indicating that many anticipated biofuels will
actually exacerbate global warming," the letter said.
The European Union and a number of European countries have recently
tried to address the land use issue with proposals stipulating that
imported biofuels cannot come from land that was previously rain forest.
But even with such restrictions in place, Dr. Searchinger's study shows,
the purchase of biofuels in Europe and the United States leads
indirectly to the destruction of natural habitats far afield.
For instance, if vegetable oil prices go up globally, as they have
because of increased demand for biofuel crops, more new land is
inevitably cleared as farmers in developing countries try to get in on
the profits. So crops from old plantations go to Europe for biofuels,
while new fields are cleared to feed people at home.
Likewise, Dr. Fargione said that the dedication of so much cropland in
the United States to growing corn for bioethanol had caused indirect
land use changes far away. Previously, Midwestern farmers had alternated
corn with soy in their fields, one year to the next. Now many grow only
corn, meaning that soy has to be grown elsewhere.
Increasingly, that elsewhere, Dr. Fargione said, is Brazil, on land that
was previously forest or savanna. "Brazilian farmers are planting more
of the world's soybeans --- and they're deforesting the Amazon to do
it," he said.
International environmental groups, including the United Nations,
responded cautiously to the studies, saying that biofuels could still be
useful. "We don't want a total public backlash that would prevent us
from getting the potential benefits," said Nicholas Nuttall, spokesman
for the United National Energy Program, who said the United Nations had
recently created a new panel to study the evidence.
"There was an unfortunate effort to dress up biofuels as the silver
bullet of climate change," he said. "We fully believe that if biofuels
are to be part of the solution rather than part of the problem, there
urgently needs to be better sustainability criterion."
The European Union has set a target that countries use 5.75 percent
biofuel for transport by the end of 2008. Proposals in the United States
energy package would require that 15 percent of all transport fuels be
made from biofuel by 2022. To reach these goals, biofuels production is
heavily subsidized at many levels on both continents, supporting a
burgeoning global industry.
Syngenta, the Swiss agricultural giant, announced Thursday that its
annual profits had risen 75 percent in the last year, in part because of
rising demand for biofuels.
Industry groups, like the Renewable Fuels Association, immediately
attacked the new studies as "simplistic," failing "to put the issue into
"While it is important to analyze the climate change consequences of
differing energy strategies, we must all remember where we are today,
how world demand for liquid fuels is growing, and what the realistic
alternatives are to meet those growing demands," said Bob Dineen, the
group's director, in a statement following the Science reports' release.
"Biofuels like ethanol are the only tool readily available that can
begin to address the challenges of energy security and environmental
protection," he said.
The European Biodiesel Board says that biodiesel reduces greenhouse
gasses by 50 to 95 percent compared to conventional fuel, and has other
advantages as well, like providing new income for farmers and energy
security for Europe in the face of rising global oil prices and
But the papers published Thursday suggested that, if land use is taken
into account, biofuels may not provide all the benefits once anticipated.
Dr. Searchinger said the only possible exception he could see for now
was sugar cane grown in Brazil, which take relatively little energy to
grow and is readily refined into fuel. He added that governments should
quickly turn their attention to developing biofuels that did not require
cropping, such as those from agricultural waste products.
"This land use problem is not just a secondary effect --- it was often
just a footnote in prior papers,". "It is major. The comparison with
fossil fuels is going to be adverse for virtually all biofuels on