Two peer-reviewed studies published in Science magazine say there has been a significant accounting error in assessing whether the biofuel industry increases or reduces greenhouse gases.
Previous studies have ignored the carbon emissions occurring worldwide as farmers respond to higher prices by converting forest and grassland to cropland to replace the grain being diverted into the biofuel sector.
Vegetation cleared to make room for expanding cropland is burned or decomposes, releasing carbon back into the atmosphere. The soil is then plowed, allowing oxygen and microbes to break down the long-stored carbon in the ground.
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And it’s that carbon dioxide-boosting effect, researchers say, that has not been accounted for in previous life cycle analyses.
“It’s not that different from doing an economic analysis that says, ‘here is the economic benefits of using cropland to produce this crop,’ without actually accounting for the rental cost of your land,” said Tim Searchinger, environmental policy researcher at Princeton University and lead author of one of the recently published studies.
Palm oil is replacing lowland peat forest in southeast Asia, soybean biodiesel and sugarcane ethanol are eating up Brazilian rainforest and corn is consuming Conservation Reserve Program lands in the United States, he said.
Gordon Quaiattini, president of the Canadian Renewable Fuels Association, said the premise behind the study is fundamentally flawed. Vast tracts of land are not being cleared to make way for biofuel production.
“The kinds of practices that they are talking about at the level they are suggesting are just not happening,” he said.
The study fails to recognize that seed technology has allowed farmers to double their yields in the past 15 to 20 years and will pave the way for another doubling of production in the next three or four years, making it possible to meet fuel and food needs.
However, Searchinger said government policies that encourage using crops to produce biofuel means more land needs to be devoted to food production somewhere around the world.
His study determined that switching from gasoline to corn-based ethanol nearly doubles greenhouse emissions over 30 years.
Even switchgrass, which has been touted as a foolproof way to conserve the environment by producing cellulose ethanol, would increase emissions by 50 percent more than gasoline over 30 years if it is grown on cropland.
“You end up with a big debt for carbon dioxide. You only pay that off over a very long time by using that land to produce biofuels.”
In the case of corn it would take 167 years to pay off the debt, which means global warming gases would be increasing until that time.
A second study found that biodiesel from soybeans has similar effects as corn ethanol.
Searchinger said farmers won’t be thrilled about his findings, but they need to look at the results in a different light. The report is saying farmers have been underappreciated for their efficient use of cropland, which keeps more land from being plowed up elsewhere.
“You can look at this as a real endorsement of the environmental benefit of good crop production,” he said.
As well, the study doesn’t preclude farmer participation in the biofuel industry. Searchinger said the appropriate biofuel policy is one that encourages the conversion of municipal, industrial, forestry and agricultural waste into fuel because that will not trigger any change in land use patterns.
Ten of the most prominent environmental scientists in the United States have sent a letter to president George Bush calling his attention to the recent research in light of his government’s decision to dramatically expand the Renewable Fuel Standard, which calls for 15 percent of all transport fuel to be biofuel by 2022.
Searchinger said it was frustrating to watch politicians deliberate about the future of the biofuel industry while he was waiting for his research to be reviewed by his peers. He said it was akin to knowing a bridge was out but being unable to warn drivers about the looming danger.
However, his report was published at a time when Canadian politicians are still pondering changes to the Canadian Environmental Protection Act that will pave the way for the proposed five percent ethanol and two percent biodiesel mandates.
“It has not impacted the support that we have,” said Quaiattini, who has been lobbying hard in Ottawa for the past two weeks.
