EPA’s Report on the Environmental Impacts of Biofuels

While the law nominally requires refiners to blend 26 billion gallons of biofuel into the American supply of transportation fuel in 2018, EPA had to reduce this year’s actual volume requirement by seven billion gallons, though, to account for the chronic unavailability of cellulosic biofuels. Of the many mistakes Congress made in 2007, one of its biggest was to structure the program around some exceptionally wrongheaded assumptions about the scale-up of future cellulosic biofuel production.

This particular post, however, focuses on something Congress got right. Some members worried about the environmental harm that could result from a dramatic expansion in the production of biofuels made from resource-intensive commodity crops. They added a provision to the law that directs EPA to produce a report every three years on “the impacts to date and likely future impacts [of the RFS] on air quality, water quality, water availability, soil conservation, ecosystem health and biodiversity, and other environmental issues.  

Notably, the climate impacts associated with the production and use of biofuels are outside the scope of the congressionally-mandated report. As we’ve discussed at length elsewhere, the RFS’s heavy reliance on conventional biofuels—especially corn ethanol and soybean biodiesel—is exacerbating climate change.

Seven years after issuing its first such report, and two years after being chastised for its tardiness by the Agency’s Inspector General, EPA has just released Biofuels and the Environment: Second Triennial Report to Congress.

The new Triennial Report validates the concerns about biofuels’ negative environmental impacts. It finds that evidence of biofuel production’s negative impact on the environment has grown since 2011, when the Agency issued its previous Triennial Report. In several places, the report confirms several of the concerns about environmental damage raised in the 2011 report (as well as some of the key findings from a critical report issued that same year by the National Research Council). Elsewhere, the new report goes further, pointing to studies released after 2011 that detail worse-than-expected environmental impacts from corn ethanol and soy biodiesel production. They include:

Land Use Change: RFS-driven biofuel demand is causing environmentally-damaging land use change in the United States and abroad. EPA’s report finds that corn and especially soybean acreage in the United States has increased at the expense of other crops and/or natural landscapes, “with strong indications that some of this increase is a consequence of increased biofuel production.” (p110)

The RFS is likely driving harmful land use change practices in other countries as well. “Reports suggest that demands for biofuel feedstocks have led to market-mediated land use impacts (both direct and indirect land use changes) in the past decade,” writes EPA. “Cropland expansion and natural habitat loss (including forests) have been observed internationally, and it is likely that increased biofuel production has contributed to these land use changes.” (pp108-109)

Air Quality Impacts: The production and use of biofuels can negatively impact air quality. According to the Triennial Report, emissions rates vary widely among ethanol refineries but “[f]acilities producing ethanol from corn and cellulosic feedstocks tend to have greater air pollutant emissions relative to petroleum refineries on a per-BTU of fuel produced basis.” (p59)

The Report also notes that the troubling linkage between ethanol use and NOx emissions persist. Joint research conducted on light-duty Tier 2 vehicles by EPA, the Department of Energy, and the Coordinating Research Council in 2009-2013 “continued to find that ethanol increased NOx emissions,” even though the vehicles were equipped with modern emissions controls. (p60)

Water Quality/Quantity Impacts: EPA’s original 2011 report identified several ways in which biofuel production threatened water quality and water availability. The 2018 report reinforces these concerns and suggests they could become more pronounced as policy-driven demand for biofuel pushes new cultivation of corn, soy, and other biofuel crops onto land that requires more irrigation and/or more fertilization.

“Modeling studies conducted since the 2011 Report suggest that demand for biofuel feedstocks, particularly corn grain, may contribute to harmful algal blooms, as recently observed in western Lake Erie, and to hypoxia, as observed in the northern Gulf of Mexico.” (p73)

EPA found that water consumption at irrigated corn farms increased between 2007 and 2012; the rate of land use change for corn production rose in more arid Western states that already face issues of water availability, including the depleted Ogallala aquifer region; and adverse water availability impacts are most likely to occur in already stressed aquifers and surface watersheds. (p83)

Ecosystems and Habitat Impacts: The ramp-up of the RFS has coincided with the loss of grasslands and wetlands in ecologically sensitive areas, including the Prairie Pothole Region. The resulting loss of habitat and the “simplification” of landscapes negatively impacts pollinators, birds, soil-dwelling organisms, and disrupts ecosystem services in both terrestrial and aquatic habitats. (p92)