Following creation of the Renewable Fuel Standard 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 farm land. 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.
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.
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.
All told, the RFS resulted in 2.8 million acres more cropland.
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 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 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 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 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 habitat that was not converted, indicating that cropland expansion is disproportionately occurring on lands that were providing higher habitat quality and greater wildlife-supporting benefits.