Abstract: Biomass energy is expected to play a major role in the substitution of renewable energy sources for fossil fuels over the next several decades. The US Energy Information Administration (EIA 2012) forecasts increases in the share of biomass in US energy production from 8 percent in 2009 to 15 percent by 2035. The general view has been that carbon emitted into the atmosphere from biological materials is carbon neutral—part of a closed loop whereby plant regrowth simply recaptures the carbon emissions associated with the energy produced. Recently this view has been challenged, and the US Environmental Protection Agency (EPA) is considering regulations to be applied to biomass energy carbon emissions. A basic approach for analyses of environmental impacts has been the use of life cycle assessment (LCA), a methodology for assessing and measuring the environmental impact of a product over its lifetime—from raw material extraction through materials processing, manufacture, distribution, use, repair and maintenance, and disposal or recycling. However, LCA approaches vary, and the results of alternative methodologies often differ (Helin et al. 2012). This study investigates and compares the implications of these alternative approaches for emissions from wood biomass energy, the carbon footprint, and also highlights the differences in LCA environmental impacts.

Abstract: The U.S. Environmental Protection Agency (EPA) continues to move ahead with regulation of greenhouse gas emissions under the Clean Air Act (CAA). Previous work has indicated that basic forms of compliance flexibility—trading—appear to be legally permissible under the relevant part (Section 111) of the CAA. This paper takes a close look at more expansive and ambitious types of flexibility: trading between different kinds of sources, biomass co-firing, and, above all, offsets. It concludes that most types of such extended flexibility are either legally incompatible with the CAA, or so legally problematic that EPA is unlikely to adopt them. This has important implications for both the costs of CAA climate policy and the level of environmental benefits that are achievable. It also creates tension between CAA climate policy and state-level policies, such as California’s, that aim to include various forms of extended flexibility.