NERA Analyses on Timing of GHG Emissions from Land Use Change: One of the most hotly debated issues regarding land use change analysis is how to properly account for GHG emissions from the land conversion over time. This is a crucially important issue, as the amount of lifecycle GHG emissions charged to ethanol can vary widely depending on what time accounting method is used. For example, under EPA’s analysis for the RFS2 (which uses a 100-year timeframe and a 2% discount rate), ethanol from a natural gas-powered dry mill reduces lifecycle GHGs by 16% compared to gasoline. However, if the timeframe is shortened to 30 years (which is the timeframe used by the California Air Resources Board), a 16% GHG reduction benefit moves to an 18% increase in GHGs relative to gasoline.
RFA recently contracted with NERA Economic Consulting to evaluate the various time accounting methods being proposed by CARB and the EPA. NERA completed two reports for RFA, both of which have been shared with CARB and EPA. The reports will also be useful as RFA and other stakeholders prepare comments on the RFS2 notice of proposed rulemaking.
NERA identified several weaknesses with methods being considered. For example, current approaches fail to account for the net impact of the LUC on land use and associated emissions after corn-based ethanol ceases to be produced. Will the land revert to its former use or to another that sequesters carbon in the soil and in vegetation? In general, one would expect that the LUC emissions would be negative after production ceased, but current methods simply assume that LUC emissions are zero after production ceases.
It is important to note that the “project horizon” relates to indirect changes in emissions associated with the use of land. Thus it is not appropriate to use the economic life of an ethanol production plant, because once converted the cropland could continue to be used to grow corn for use in replacement production plants if demand continued past the useful life of the original plant.
Another scenario that should be considered is that land converted today as the indirect result of corn-based ethanol production will substitute, after production of such ethanol ceases, for land that otherwise would have been converted to cropland in the future. Under this scenario, for example, if the economic lifetime of corn-based ethanol is 25 years, an acre cleared today for corn used in ethanol will substitute for an acre that other would be converted to cropland 25 years later. The availability of that land will decrease the price of cropland, thus reducing the incentive to convert other types of land to cropland. Under this scenario, LUC that occurs today as a result of increased production of corn-based ethanol effectively shifts LUC emissions closer in time. Although LUC emissions occur starting now, LUC emissions that otherwise would have started later will not occur.
RFS2 NOPR Published in Federal Register; Technical Details Posted on Docket: The Notice of Proposed Rulemaking (NOPR) for the expanded Renewable Fuels Standard (RFS) was published in the Federal Register on May 26, formally beginning the 60-day public comment period. In conjunction with publication of the NOPR in the Federal Register, more than 200 supporting documents were posted to the public docket providing additional technical details on EPA’s lifecycle GHG analysis and other technical aspects of the proposal.
RFA staff and contractors are reviewing all of the technical documentation posted on the docket, particularly the materials related to EPA’s indirect land use change analysis. To view the RFS2 docket, click here.
RFA’s Kristy Moore to Receive ASTM Award: RFA Director of Technical Services Kristy Moore will be presented with an ASTM “Award of Appreciation” at the June 23 meeting of the ASTM Subcommittee D02.A on Gasoline and Oxygenated Fuels. The award will be presented by Ken Henderson, Chair of Committee D02. According to ASTM, Kristy “…will be recognized for her valuable support of SCA providing information on ethanol and ethanol fuels and for the perspective she brings on the fuel quality interests of the ethanol industry.” Kristy, who is one of four ASTM Subcommittee D02.A participants set to receive awards, also chairs the Mid-Level Ethanol Blends Task Group.Permalink + Share This