This paper documents a forward looking multi-regional general equilibrium model developed from the latest version of the recursive-dynamic MIT Emissions Prediction and Policy Analysis (EPPA) model. The model represents full inter-temporal optimization (perfect foresight), which makes it possible to better address economic and policy issues such as borrowing and banking of GHG allowances, efficiency implications of environmental tax recycling, endogenous depletion of fossil resources, international capital flows, and optimal emissions abatement paths among others. It was designed with the flexibility to represent different aggregations of countries and regions, different horizon lengths, as well as the ability to accommodate different assumptions about the economy, in terms of economic growth, foreign trade closure, labor leisure choice, taxes on primary factors, vintaging of capital and data calibration. The forward-looking dynamic model provides a complementary tool for policy analyses, to assess the robustness of results from the recursive EPPA model, and to illustrate important differences in results that are driven by the perfect foresight behavior. We present some applications of the model that include the reference case and its comparison with the recursive EPPA version, as well as some greenhouse gas mitigation cases where we explore economic impacts with and without inter-temporal trade of permits.

In this study, we present a new modeling framework and a large ensemble of climate projections to investigate the uncertainty in regional climate change over the United States (US) associated with four dimensions of uncertainty. The sources of uncertainty considered in this framework are the emissions projections, global climate system parameters, natural variability and model structural uncertainty. The modeling framework revolves around the Massachusetts Institute of Technology (MIT) Integrated Global System Model (IGSM), an integrated assessment model with an Earth System Model of Intermediate Complexity (EMIC) (with a two-dimensional zonal-mean atmosphere). Regional climate change over the US is obtained through a two-pronged approach. First, we use the IGSMCAM framework, which links the IGSM to the National Center for Atmospheric Research (NCAR) Community Atmosphere Model (CAM). Second, we use a pattern-scaling method that extends the IGSM zonal mean based on climate change patterns from various climate models. Results show that the range of annual mean temperature changes are mainly driven by policy choices and the range of climate sensitivity considered. Meanwhile, the four sources of uncertainty contribute more equally to end-of-century precipitation changes, with natural variability dominating until 2050. For the set of scenarios used in this study, the choice of policy is the largest driver of uncertainty, defined as the range of warming and changes in precipitation, in future projections of climate change over the US.

© 2014 Springer Science+Business Media

How best to take action to address phenomenon of global warming has spawned a variety of scientific, political, and legal debates in the United States. This Article discusses the United States Environmental Protection Agency's (EPA) authority under the Clean Air Act (CAA) to regulate greenhouse gas emissions, which scientists have identified as leading to human-induced climate change. Further, the Article attempts to disentangle the domestic regulation of these emissions from an attempt to implement the terms of the Kyoto Protocol to the Framework Convention on Climate Change without ratification by the United States Senate. The Article concludes that EPA's regulatory authority in this area is uncertain and that Congress could control global warming effectively and legitimately by amending the CAA to explicitly authorize EPA to promulgate standards for greenhouse gas emissions.

© 2000 Environmental Law

Regulation of aviation’s contribution to the global problem of climate change is increasingly likely in the near term, but the method agreed upon by most economists—a multi-sectoral market-based approach such as a cap and trade system—is opposed by industry stakeholders. An efficient economy-wide policy would determine the optimal level of sectoral emissions reductions, but industry groups have instead proposed independent aviation-sector goals for carbon mitigation and technology adoption. This thesis asks the question: how much should airlines reduce their emissions, and which technologies will be necessary to achieve those reductions.

In order to comprehend the problem of mitigation costs and outcomes within the context of the global economy, I introduce an aviation-resolved version of the MIT Emissions Prediction and Policy Analysis model; a computable general equilibrium model of the global economy. In EPPA-A, the social accounting matrix is re-balanced to include aviation, a non-unity income elasticity of demand is introduced, and substitution elasticity parameters are estimated. Additionally, I include an additional module to analyze the potential non-market impacts of government infrastructure on aviation emissions by explicitly modeling an advanced Air Traffic Control sector.

Several policy scenarios are applied to the model including: an idealized economy- wide cap and trade system in each developed nation or region, and an aviation-sector- only cap within an economy-wide cap, both with and without trading enabled between the aviation cap and the economy-wide cap. Each policy scenario is compared to a business-as-usual case, and relative welfare loss under each policy is calculated. The business-as-usual and economy-wide cap policies are also run with the advanced Air Traffic Control module enabled, and the efficacy is determined.

I find that in the context of total economic welfare, the method of aviation regulation is of little significance; the differences in results among the different policy scenarios are very small (on the order of 0.002% in the U.S.). However, the price of aviation and sector output are more responsive. When trading between an aviation- sector-only cap and the economy-wide cap is enabled, outcomes are practically identical. When trading is not allowed, the price of aviation increases 21.8%, and output falls 32.8% compared to the economy-wide policy-only case.  I find that national welfare outcomes are sensitive to international trade, and border adjustments for aviation emissions are important. Finally, the efficacy of advanced Air Traffic Control infrastructure, and the economic welfare gained or lost, is sensitive to the parameter estimates which exhibit high uncertainty. I find that the low-efficacy parameters result in slightly lower fuel intensity, but are also net-welfare decreasing, while the high parameter estimates increase welfare, but result in an infeasible reduction in sectoral energy intensity.