Ethanol and land use changes

Feb 2008

On February 2008, Science published two studies that examined the greenhouse gas impact of land use changes caused by the growing demand for biofuels. Within hours, news of the studies was carried by a remarkable number of media outlets.
The studies consider two types of land use changes. One is direct: the conversion of noncrop lands into energy crop lands (e.g. grassland is plowed up to plant corn for ethanol). The other is indirect: the displacement of food and feed crops on existing cropland by energy crops, which may result in expanding crop production in other parts of the world into native habitats to make up for the loss of food and feed.
The studies published in Science, as well as other studies in the field, have brought together in one place a great deal of information about the carbon stored in lands of different uses.
With regard to agriculture and biofuels, the studies present part of the data needed for a what-if scenario, but not all of it. For example, the efficiencies of future ethanol plants and the increased greenhouse gas emissions from extracting crude oil should be taken into account. More analytical work is needed to estimate the net loss in animal feed from growing corn for ethanol on soybean acres.

By: D. Morris (Institute for Local Self-Reliance)

 
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