Overview of EMF 22 U.S. transition scenarios
Introduction
There have been a variety of different policy measures proposed to limit greenhouse gas (GHG) emissions in the United States; the most prominent of them have featured a broad cap-and-trade system as the central policy mechanism. Recent cap-and-trade proposals have put forward limits through the year 2050 and have featured banking of allowances over time and limited borrowing. Much of the focus has been on a cap set to 20% or less of current emissions by 2050, gradually reducing the amount of allowances over time. However, the actual level of domestic reduction that would occur depends on the extent to which external credits are allowed into the system and their availability. Actual domestic emissions reductions could be much less under some proposals that allow as much as 2 billion metric tons of credits per year from outside the system (e.g. H.R. 2454). The EMF 22 exercise developed three paths of allowance availability that would limit cumulative emissions through 2050. Interesting questions that are addressed include: (1) what are the costs of different levels of emissions reductions? (2) How will the reductions be allocated across time? (3) How will reductions be allocated across sectors? And (4) what are the implications of climate policy for the energy producers and consumers?
The EMF 22 U.S. transition scenarios study explores these questions through a comparison of results from six modeling teams across three standardized climate policy scenarios. Each modeling team was required to provide results related to economics, emissions, and energy systems for a reference scenario and three policy scenarios. Modelers were free to make their own decisions on demographics, baseline energy consumption, technology availability, and technology cost.
Section 2 details the study design. This section includes a list of modeling teams and scenarios, as well as a description of how these scenarios relate to existing U.S. congressional bills and the international component of the EMF 22 study. 3 Emissions pathways, 4 Primary energy and electricity generation, 5 Economic implications of meeting emissions goals provide results from the study on emissions pathways, energy systems, and economic indicators, respectively. Section 6 summarizes the results, and Section 7 provides a preview of issues explored by the individual modeling teams in their papers.
Section snippets
Modeling teams
Six modeling teams completed the U.S. transition scenarios in the EMF 22 study; the models include: the Applied Dynamic Analysis of the Global Economy model (ADAGE) from the Research Triangle Institute; the Emissions Predictions and Policy Analysis model (EPPA) from the Massachusetts Institute of Technology; the Model for Emissions Reductions in the Global Environment (MERGE), from the Electric Power Research Institute; MiniCAM, from the Pacific Northwest National Laboratory/Joint Global Change
Emissions pathways
As discussed previously, actual emissions paths will diverge from the allowance allocation paths because of banking and borrowing. Fig. 3 shows total U.S. GHG emissions in the reference and three policy scenarios for each model.4
Primary energy and electricity generation
The imposition of a climate policy changes the energy system substantially. In this section, we look at the effect of policy on the consumption of primary energy and the generation of electricity. Here we focus on a comparison of the reference and 203 GtCO2e scenarios.
Economic implications of meeting emissions goals
In this study we focus on two types of economic impacts: allowance prices and aggregate economic consumption impacts. The allowance price is a measure of the marginal cost of abating GHG emissions. The consumption impact is a measure of the change in consumption of goods and services in the economy, one measure of the aggregate economic cost. It measures how much less goods and services households can purchase given the rises in energy prices and other costs resulting from GHG abatement.
Summary
The results from the EMF 22 U.S. transition scenarios exercise presented in this paper allow for a comparison across six models that have been used for various analyses of climate change issues, and across three scenarios that span a wide range of potential U.S. emissions targets. Some of the key insights from this paper are described in this summary.
What are the costs of different levels of emissions reductions? The costs of different levels of action can be measured in different ways and vary
Other issues addressed in this study
The results of the EMF 22 U.S. transition scenarios exercise presented in this overview paper cover just the broad insights from the core scenarios of the exercise. In their individual papers, all of the modeling teams provide additional insights into the economic analysis and policy assessment of climate mitigation goals by conducting additional analyses beyond the required core U.S. transition scenarios. The range of additional issues analyzed include: the effects of technology availability
Acknowledgments
The authors wish to acknowledge the efforts of: the individual modeling teams that produced the scenarios that are presented here; Sabrina Delgado-Arias, and Haewon Chon, who helped manage the data base for these scenarios; Leon Clarke, Richard Tol, Jae Edmonds, Rich Richels, Tom Rutherford, and Chris Boehringer, who were partners in the development and management of this study; and David Goldblatt, who edited the text of this paper and of several others.
References (14)
- et al.
Feasible climate targets: The roles of economic growth, coalition development and expectations
Energy Economics
(2009) - et al.
International climate policy architectures: overview of the EMF-22 international scenarios
Energy Economics
(2009) - et al.
The structural effects of cap and trade climate policy
Energy Economics
(2009) - et al.
The value of advanced technology in meeting 2050 greenhouse gas emissions targets in the United States
Energy Economics
(2009) - et al.
The cost of climate policy in the United States
Energy Economics
(2009) - et al.
U.S. climate mitigation pathways post-2012: Transition scenarios in ADAGE
Energy Economics
(2009) - et al.
A top-down bottom-up modeling approach to climate change policy analysis
Energy Economics
(2009)