Burning and plowing grasslands, rain forest, savannas and peat land for crop cultivation releases huge amounts of carbon dioxide into the atmosphere.
In a stunning reversal of environmental doctrine, researchers
have determined that ethanol and other heavily subsidized "biofuels" are far
more polluting than the petroleum they were developed to replace. This latest
policy blunder illustrates the costly consequences of ignoring science in
climate change policy.
Two studies published online Feb. 7 by the journal "Science"
report that the cultivation of corn for ethanol and other biofuel feedstocks
substantially increases emissions of the greenhouse gases that are supposedly
causing climate change. One of the studies calculated that corn-based ethanol,
instead of producing a 20-percent reduction, nearly doubles greenhouse gas
emissions over 30 years while the production of fuel from switchgrass increases
emissions by 50 percent.
The excess emissions result from land conversions that are
driven by demand for corn and other crops used to produce "renewable" fuels.
According to the researchers, soil and plants together store 2.7 times more
carbon than is present in the atmosphere. Thus, burning and plowing grasslands,
rain forest, savannas and peat land for crop cultivation releases huge amounts
of carbon dioxide into the atmosphere. Moreover, the loss of plants and soil
reduces the absorption of carbon dioxide from the atmosphere that otherwise
The research team, headed by Timothy Searchinger of Princeton
University, calculated that one hectare of corn grown for ethanol reduces
greenhouse gases by 1.8 metric tons per year. But the conversion of one hectare
of forest produces between 604 metric tons and 1,146 metric tons of greenhouse
gases. It can take centuries before this "carbon debt" is reversed through the
use of biofuels in place of petroleum.
Environmental benefit, in the form of reduced emissions of
greenhouse gases, may be achieved if biofuels are produced with "waste biomass,"
such as wood by-products and agricultural debris, or from biomass grown on
abandoned agricultural lands, researchers say.
Excess carbon emissions are not the only unintended consequence
associated with biofuels. The National Academy of Sciences has reported that
ethanol production is taxing water supplies, while the boom in corn and other
feedstock production fosters soil erosion and fertilizer runoff. Also overlooked
is the effect of biofuel policy on fuel prices: The lower costs engendered by
subsidies fuels energy consumption and, in turn, emissions of greenhouse gases.
Corn acreage in the United States increased 18 percent — or 14
million acres — between 2006 and 2007. Much of the increase is the result of
subsidies that will exceed $5 billion this year alone. The impact on global
agriculture is dramatic. The subsidies impel American farmers to devote evermore
acres to corn for ethanol. The consequent reduction in U.S. supplies of soybeans
and other displaced crops sends commodity prices higher, which prompts farmers
elsewhere, particularly in Brazil and Southeast Asia, to clear land for
Recent legislation promises to intensify the trend. The federal
energy bill signed by President George Bush on Dec. 20, 2007, calls for biofuels
to comprise 15 percent of all transport fuel by 2022 — or 36 billion gallons per
year compared to 7.5 billion now produced annually. Meanwhile, the European
Union last month proposed a 10 percent biofuel mandate.
Michigan lawmakers and Gov. Jennifer Granholm, too, have been
overtaken by biofuel fever, proposing to expand state tax breaks and other
economic incentives for the production of ethanol and crop-based fuels in the
The obvious disconnect between environmental policy and science
is hardly surprising given the political pressure to act on climate change. As
Nicholas Nuttall, a spokesman for the United Nations Environmental Program told
the New York Times: "There was an unfortunate effort to dress up biofuels as the
silver bullet of climate change."
But contrary to conventional wisdom, there’s no "consensus"
about a causal link between carbon dioxide and climate change; predictions of
future warming; or what effects may result from climate change. Unfortunately,
that hasn’t kept lawmakers and regulators from imposing all manner of dictates
in utter ignorance of the actual effects on the environment.
Diane S. Katz is director of science, environment and technology
policy with the Mackinac Center for Public Policy, a research and educational
institute headquartered in Midland, Mich.
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