The federal government's programs designed to spur the creation of more plant-based ethanol for America's fuel supply has been bad for the environment, according to a new study.
A study published in the Proceedings of the National Academy of Sciences of the United States of America points to some unintended negative consequences of government ethanol programs.
In the report, called "Recent land use change in the Western Corn Belt threatens grasslands and wetlands," Christopher K. Wright and Michael C. Wimberly, of the Geographic Information Science Center of Excellence at South Dakota State University, found that more than 1.3 million acres of grassland have been lost from 2006 to 2011 in North Dakota, South Dakota, Nebraska, Minnesota and Iowa.
The federal government has encouraged the production of corn and soy-based ethanol through ethanol subsidies and by requiring that ethanol be added to gasoline for automobiles, which has encouraged the conversion of grasslands to farmlands for the production of corn and soy. Wright and Wimberly also note that federal crop insurance programs have encouraged farmers to take greater risk when choosing where to plant crops, thus creating even greater incentive to convert grassland to cropland.
The government's ethanol programs were designed reduce atmospheric carbon, thought to be a source of global warming. Ethanol and fossil fuels both put carbon dioxide in the air when they are burned, but plant-based fuels first take carbon out of the air (when the plants grow) before putting the carbon back in the air when they are burned. Fossil fuels, on the other hand, take carbon from under the ground and put it in the air. This is why ethanol is advertised as being "carbon neutral."
The authors point to other studies, though, showing that ethanol is not carbon neutral, particularly when grassland, which does a good job of removing carbon from the atmosphere, is destroyed to grow the crops in the first place.
The rate of conversion of grassland to farmland has been comparable to the rates of deforestation in Brazil, Malaysia and Indonesia in the 1980s and 1990s, Wright and Wimberly found.
There other negative effects as well, when environmentally sensitive grasslands are destroyed to grow corn or soy for fuel.
"In aggregate," they wrote, "conversion has been concentrated on more marginal lands characterized by high erosion potential, shallow soils, poor drainage, and less suitable climates for corn/soy production."
Wright and Wimberly suggest that, instead of planting corn and soy for ethanol, farmers plant mixed-grass prairie to harvest and convert to ethanol.