New Research Proves Biofuels Policy Driving Environmental Harm

Groundbreaking study provides most comprehensive assessment to date of direct connection between U.S. biofuels policy and specific habitat, water consumption, and climate change impacts.

WASHINGTON, D.C. — New research shows the Renewable Fuel Standard and its implementation are fueling environmental harm that is destroying monarch butterfly habitat and forage, draining western aquifers, accelerating climate change and numerous other effects. The new research, prepared by the University of California-Davis, Kansas State University, and University of Wisconsin, provides the most detailed and comprehensive assessment to date of the direct connection between U.S. biofuels policy and specific economic and field-level environmental changes following passage of the Renewable Fuel Standard 10 years ago.

Read an overview of the research at:

Original research can be found at:

Both sites contain maps showing which impacts are most prevalent in specific states.

The compilation of research was presented in February at the American Association for the Advancement of Science.  The new findings come at a critical time, as public officials are preparing to re-write national biofuel policy due to a mandated “re-set” of the law.

“There is no dispute that U.S. biofuels policy is driving environmental harm,” said Aaron Smith, professor, agricultural and resource economics, University of California, Davis. “The Renewable Fuel Standard created a strong economic incentive to increase domestic corn production to meet the federal mandate for new biofuels. The ensuing expansion and intensification of crop agriculture has transformed the landscape, leading to a cascade of negative impacts on wildlife habitat, water resources, and the climate.”

Main findings of the research include:

  1. The Renewable Fuel Standard (RFS) raised corn prices 31 percent and soybean prices 19 percent, driving demand for those crops.
  2. The RFS led to an intensification of corn production, as farmers planted more corn on existing cropland by an average of 6.9 million acres per year between 2008 and 2016.
  3. The RFS also led to the conversion of 1.6 million acres of grassland, shrubland, wetland and forestland into cropland between 2008 and 2016.
  4. This RFS-led land conversion contributed to the continued decline of habitat, including milkweed—the sole food source for monarch butterfly larvae
  5. Due to the RFS, an additional 1.2 million acres of cropland remained in production instead of being retired to pasture or retired through farm conservation programs.
  6. Land-use changes driven by the RFS contributed about 27.1 million metric tons of carbon dioxide per year into the atmosphere, the equivalent of more than 7 coal-fired power plants.
  7. The RFS led to increased water consumption through irrigation of newly converted crops from natural areas, and existing crops that remained in production instead of being retired. Nebraska experienced the largest irrigation expansion.

The new research follows an assessment by the EPA warning that U.S. biofuels policy was likely having negative impacts on the environment. The new research confirms those findings.

What researchers are saying:

Aaron Smith, professor, agricultural and resource economics, University of California, Davis, whose research examines the economic changes being driven by the RFS:

“Ethanol has a long history as a prospective motor fuel, but it was only able to gain market penetration recently due to government mandates. Passage of the Renewable Fuel Standard influenced farm commodity prices, substantially boosting corn and soybean prices, and creating strong incentives for farmers to plant more of those crops. These economic changes set the stage for the environmental changes we’re seeing today.”

Tyler Lark, associate researcher, Center for Sustainability and the Global Environment University of Wisconsin, whose research examines land-use changes, increased water use for irrigation, and climate change impacts related to the RFS:

“We’ve known for years that the American landscape is changing—with native prairies, wetlands and even forests being replaced by rows of corn—now we finally know how much of it is connected to biofuels. These trends are clearly observable in places like the Prairie Potholes of the Dakotas and the rolling hills of Southern Iowa and Northern Missouri, where land conversion has led to the loss of habitat for everything from migratory ducks to Monarch butterflies.  But these changes don’t just impact wildlife, they also affect our water resources and climate change, in real ways that affect everyone, almost every day.”  

Nathan Hendricks, associate professor, agricultural economics, Kansas State University, whose research examines the impact of the RFS on crop intensification and extensification:

“The Renewable Fuel Standard has changed the agricultural landscape. Farmers are planting more corn on existing cropland and are rotating crops less in the central Corn Belt. Increases in corn planting is especially prevalent in the Dakotas, Northwest Minnesota, Iowa, and Mississippi Delta regions. The impacts of the RFS on crop prices have also caused farmers to convert grassland to crop production, especially in the Dakotas, Southern Iowa, Northern Missouri, Nebraska, and Kansas. These changes have implications for greenhouse gas emissions, habitat, and water resources.”

Collin O’Mara, president and CEO, National Wildlife Federation, which is helping disseminate the research to raise awareness about the impacts of the RFS on wildlife, habitat and natural resources:

“The new research eliminates any doubt that current U.S. biofuels policy is destroying habitat, polluting waterways, and increasing climate pollution, jeopardizing the health of people, communities, and wildlife. We urge federal officials to embrace common-sense, bipartisan solutions to advance better biofuels the right way – solutions that protect our drinking water and public health, while supporting family farms and confronting the climate crisis that threatens people and wildlife alike.”

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