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New research findings link US biofuel mandate to environmental harm – NWF

In the United States (US), new research suggests that the Renewable Fuel Standard (RFS) and its implementation are, according to the National Wildlife Federation (NWF), fueling an environmental disaster that is destroying monarch butterfly habitat and forage, draining western aquifers, accelerating climate change and numerous other effects.

On June 23, 2011, the US EPA finalised regulations to help prevent misfueling of vehicles, engines, and equipment not covered by the partial waiver decisions. These regulations require all E15 fuel dispensers to have a label that informs consumers about what vehicles can, and what vehicles and equipment cannot use E15 (image courtesy RFA).

The new research, prepared by the University of California-Davis, Kansas State University, and the University of Wisconsin-Madison, provides the most detailed and comprehensive assessment to date of the direct connection between US biofuels policy and specific economic and field-level environmental changes following passage of the Renewable Fuel Standard (RFS) a decade ago.

Back then, the federal government began requiring that ethanol and other plant-based fuels be blended into the national fuel supply. The subsequent intensification and expansion of industrial-scale agricultural production in the US  and around the world have, the NWF says, had a huge impact on the environment.

The “true scale of that impact” has become clearer over time, and newly completed research has eliminated any remaining doubt – “America’s biofuel mandate has made our environment worse, rather than better, putting at risk our health and the viability of many wildlife species, while adding billions of dollars in costs to consumers and taxpayers” the NWF says.

EPA’s Second Triennial Report to Congress

According to NWF, hundreds of scientific studies over the last 10 years have documented the negative effects of growing crops like corn and soybeans and turning them into massive quantities of fuel. The US Environmental Protection Agency (EPA) compiled the findings of many of those studies into an authoritative report to Congress last year.

The conclusions of the “Biofuels and the Environment: The Second Triennial Report to Congress” was sobering, and new research since the report has only added to the concerning tally. Citing independent university research as well as surveys conducted by the US Department of Agriculture (USDA), the EPA report confirmed that commercial crop planting had expanded following the mandate – to the tune of between 4 million and 7.8 million acres nationwide.

A recently updated analysis from the University of Wisconsin-Madison shows that conversion has continued in the years following the timeframe considered in the EPA report, bringing the total to more than 10 million acres – an area twice the size of Massachusetts that has been newly plowed for crop production, much of it for fuel crops like corn and soybeans.

This expansion countered a long-term trend of declining farmland in America as the country has become more urbanized and agricultural production has become more efficient and highly concentrated to fewer, larger farms. So while overall crop acreage today is roughly the same as it was back in 2007, cropland lost to urbanization in certain parts of the country has been offset by new acres broken out in other places.

Satellite imagery used

The University of Wisconsin has used satellite images to show exactly where this destruction is occurring, and its latest research has shown that it has continued even as biofuel production has plateaued, showing the dynamic nature of land use, and how uncultivated habitats remain at risk of conversion.

Following the creation of the Renewable Fuel Standard (RFS) in 2007, demand for corn surged in order to meet the vast new mandate for corn ethanol, with a smaller increase in demand for soybeans for biodiesel. This new market demand stimulated an enduring price signal for these crops, as well as others such as wheat that compete for the same farmland.

Milkweed stems lost due to conversion of grasslands, shrublands, and wetlands to corn and soy production in the Midwest, 2008-16 (image courtesy University of Wisconsin-Madison).
Milkweed stems lost due to the conversion of grasslands, shrublands, and wetlands to corn and soy
production in the Midwest, 2008-16 (image courtesy University of Wisconsin-Madison).

Specifically, the RFS has inflated the price of corn by about 31 percent, and soy and wheat by about 20 percent above what they would be without the program. According to NWF, the new suite of research draws a direct line between that increased demand for fuel crops and a host of changes across the American landscape including:

Increased cropland and intensification of corn production

  • The RFS increased annual area planted to corn on existing cropland by an average of 6.9 million acres during 2009-16, or about 8.2 percent above what the levels would have been. 8 million acres shifted into continuous corn production from other crops or crop rotation.
  • 1.6 million acres of new land (typically pasture or uncultivated grasslands) were converted to cropland because of the RFS-induced demand. This occurred during a period of larger land conversion to the tune of 10 million acres converted from 2008-2016, which is 19 percent more cropland expansion than would have occurred without the RFS.
  • An additional 1.2 million acres stayed in crop production that otherwise would have been put into the Conservation Reserve Program, pasture, or left to other uses. In total, the RFS resulted in 2.8 million acres more cropland.

Carbon emissions

  • Land conversion due to the RFS released 116.2 teragrams (or million metric tons) of CO2e from 2008 to 2016, or about 14.5 Tg CO2e per year. Foregone carbon sequestration due to crop production rather than CRP enrollment totaled 102.7 Tg, 12.8 Tg annually. In total, the RFS is responsible for an additional 219 Tg CO2e climate pollution in the atmosphere.
  • The annual emissions from RFS-induced land conversion were equivalent to 5.8 million cars on the road, or 7 coal-fired power plants. Additional fertilizer use and the associated release of nitrous oxide (NOx) added nearly as much climate pollution as another coal plant.

Water use and irrigation

  • The extent of irrigated acres over the Ogallala aquifer generally increased over time from 2000 to 2017.
  • The average amount of irrigated fields in the seven years following the creation of the RFS was 9.75 percent higher than the average in the 7 years prior to the program. The year with the most irrigated land in the 7 post-RFS years saw 7.1 percent more irrigated land than the highest year pre-RFS.
  • Over the whole time period (7 years pre- and 11 years post-RFS), the average extent after the RFS was 11.6 percent higher than in the previous period, and the maximum extent was 17.3 percent higher.
  • Crops grown on new croplands due to the RFS used 10.5 billion gallons per year of more water (from any source) than the grasslands and natural vegetation they replaced. Similarly, crops that grew on cropland which otherwise would have been abandoned in absence of the RFS consumed over 6.2 billion more gallons of water annually than the grasslands with which they would have been replaced.
  • In 2012 – in the midst of a devastating drought – some ethanol refineries in arid states (AZ, ID, WY) were producing ethanol from corn that had required more than 2 000 gallons of irrigated water for each gallon of ethanol produced. Several others (in CA, NE, and OR) required more than 1 000 gallons of irrigation per gallon of ethanol.


  • 41 federally listed threatened or endangered species had at least 10 acres of land converted to crop production between 2008 and 2016 within the boundaries of their “critical habitat” as designated by the U.S. Fish and Wildlife Service.
  • 16 aquatic threatened or endangered species saw the conversion of at least 5 percent of the land in watersheds surrounding their critical habitat, increasing the risk of farm runoff. A total of 107 species saw some conversion in their watersheds.
  • An estimated 223 million milkweed stems, essential for the migratory Monarch butterfly were lost on converted grasslands, wetlands, and shrublands across the Midwest 2008-16 – 17 percent of the total remaining in the region as of 2014. This estimate is 15 times larger than a previous estimate from 2016 and goes against conservation efforts that say we need to add an additional 1.3 billion stems.
  • In the Prairie Pothole Region – known as America’s duck factory – areas estimated to support 138 000 duck pairs were recently converted to crop production. On average, habitat converted to cropland was predicted to support nearly twice as many birds as existing croplands.
  • In addition, areas of habitat that were recently converted to cropland had supported roughly 37 percent more duck pairs per acre than other remaining habitats that were not converted, indicating that cropland expansion is disproportionately occurring on lands that were providing higher habitat quality and greater wildlife-supporting benefits.

However, the EPA, as well as the ethanol industry, has repeatedly stated that there has been no link showing that the biofuel mandate was responsible for this expansion, as opposed to other factors such as increased demand for American agricultural products overseas.

The new findings, the NWF says, “explicitly make that link” to show just how much the policy has driven land-use change by providing the incentive to plant crops in new areas, and the associated environmental impacts.

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