Senator Thune Introduces Bill to Change Greenhouse Gas Accounting Methodologies for Renewable Fuels

On April 30, Senator John Thune (R-SD) introduced a bill (S. 943) providing new direction to EPA in determining the carbon footprint of renewable fuels. Currently, the national Renewable Fuel Standard (RFS) requires that renewable fuels meet specific emissions reduction thresholds (greenhouse gas emissions "screens") in order to be eligible for the program. As the law is currently written, EPA is required to determine the carbon footprint of each fuel based on both direct emissions and significant indirect emissions. Direct emissions are the measurable, quantifiable emissions incurred while growing and harvesting biomass, as well as producing and using the fuel. Indirect emissions, on the other hand, are market-mediated emissions that are assumed to occur as a result of demand-driven expansion of global agriculture. The inclusion of indirect emissions in greenhouse gas accounting has been a controversial issue, with many arguing that current estimates are insufficiently supported to justify inclusion in public policy at this time.

S. 943 would require the EPA to count only the direct emissions in making this assessment. Furthermore, the bill would prohibit states from including indirect emissions in state-level policies. Both EPA and the California Air Resources Board (CARB) have recently released greenhouse gas accounting methodologies that include indirect emissions. Consequently, both methodologies come up with carbon footprints for several common renewable fuels (such as corn ethanol and soy-based biodiesel) that are higher than their petroleum counterparts.

In addition to the indirect emissions provisions, Senator Thune's bill would grant the EPA authority to waive the emissions screens altogether if they prove unachievable, if they are resulting in economic harm to the renewable fuels industry, or if they are contributing to increased petroleum dependence. On May 5, Representative Jerry Moran (R-KS) introduced similar legislation (H.R. 2283) in the House of Representatives.