Abstract: Over the last half decade, a variety of federal legislative proposals for limiting greenhouse gas (GHG) emissions have been put forward, most of which would set a price on carbon. As of early 2013, the one politically plausible policy appears to be a carbon tax, passed as part of a larger fiscal reform package. Meanwhile, the US Environmental Protection Agency has begun regulating GHG emissions from a variety of sources using its authority under the Clean Air Act. It may be necessary to choose between these two policies, however. The Waxman–Markey cap-and-trade bill that failed in 2009 would have preempted much of this authority, and it appears likely that a carbon tax law would do the same. But how can one make this choice? What are the key questions and issues to consider? The purpose of this paper is to compare these policies. Our aim here is therefore not to determine whether an exchange is wise or unwise. Instead, our intention is to give policymakers and other interested readers an impartial assessment of both policies and, in particular, the features that are important to a comparative evaluation. We don’t give answers, but hope at least to give the right questions to ask.

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: Several recent studies have used simulation models to quantify the potential effects of recent environmental regulations on power plants, including the Mercury and Air Toxics Standards (MATS), one of the US Environmental Protection Agency’s most expensive regulations. These studies have produced inconsistent results about the effects on the industry, making general conclusions difficult. We attempt to reconcile these differences by representing the variety of assumptions in these studies within a common modeling platform. We find that the assumptions, and their differences from the way MATS will be implemented, make a substantial impact on projected retirement of coal-fired capacity and generation, investments that are required, and emissions reductions. Almost uniformly, the actual regulation, when examined in its final form and in isolation, provides more flexibility than is represented in most models. We find this leads to a smaller impact on the composition of the electricity generating fleet than most studies have predicted.