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Despite decades of scientific research and policy actions to control mercury, exposure to toxic methylmercury continues to pose risks to humans and the environment. This article critically reviews the linkages between scientific advancements and mercury reduction policies aimed at reducing this risk, focusing on the challenges that mercury poses as an issue that crosses both spatial and temporal scales. Scientific aspects of the mercury issue at various spatial and temporal scales are reviewed, and policy examples at global, national and local scale are analysed. Policy activity to date has focused on the mercury problem at a single level of spatial scale, and on near-term timescales. Efforts at the local scale have focused on monitoring levels in fish and addressing local contamination issues; national-scale assessments have addressed emissions from particular sources; and global-scale reports have integrated long-range transport of emissions and commercial trade concerns. However, aspects of the mercury issue that cross the political scale (such as interactions between different forms of mercury) as well as contamination problems with long timescales are at present beyond the reach of current policies. It is argued that these unaddressed aspects of the mercury problem may be more effectively addressed by (1) expanded cross-scale policy coordination on mitigation actions and (2) better incorporating adaptation into policy decision-making to minimize impacts.

© 2011 Royal Society of Chemistry

Computable general equilibrium (CGE) models seeking to evaluate the impacts of electricity policy face difficulties incorporating detail on the variable nature of renewable energy resources. To improve the accuracy of modeling renewable energy and climate policies, detailed scientific and engineering data are used to inform the parameterization of wind electricity in a new regional CGE model of China. Wind power density (WPD) in China has been constructed using boundary layer flux data from the Modern Era Retrospective-analysis for Research and Applications (MERRA) dataset with a 0.5° latitude by 0.67° longitude spatial resolution. Wind resource data are used to generate production cost functions for wind at the provincial level and offshore, incorporating technological parameters and geographical constraints. With these updated wind production cost data to parameterize the wind electricity option in a CGE model, an illustrative policy analysis of the current feed-in tariff (FIT) for wind electricity is performed. Assuming a generous penetration rate and no interprovincial interconnection, we find that the contribution of wind to total electricity generation is 215 TWh, reducing CO2 emissions by 3.5%. We discuss the relative merits of the FIT by province. Our analysis shows how wind electricity resource can be differentiated based on location and quality in a CGE model and applied to a analyze climate and energy policies.

Natural gas in China has a substantial potential to grow from its current small share of the total energy use. The growth will contribute to lower air pollution and carbon emissions. Shale gas resources provide an opportunity for expansion and their development reduces dependence on energy imports. We estimate the costs of shale gas supply in China and use the MIT Emissions Predictions and Policy Analysis (EPPA) model to consider the impact of shale gas development on production, consumption, and international trade in natural gas. China’s shale gas production is assessed to be more expensive in comparison to the current shale gas production in the U.S. The large shale resource might be a potential game changer in terms of energy production and consumption in China. However, even with favorable economic conditions, a substantial development of this resource might take a considerable amount of time.

Estimates of greenhouse gas (GHG) emissions from shale gas production and use are controversial. Here we assess the level of GHG emissions from shale gas well hydraulic fracturing operations in the United States during 2010. Data from each of the approximately 4,000 horizontal shale gas wells brought online that year is used to show that about 900 Gg CH4 of potential fugitive emissions were generated by these operations, or 228 Mg CH4 per well—a figure inappropriately used in analyses of the GHG impact of shale gas. In fact, along with simply venting gas produced during the completion of shale gas wells, two additional techniques are widely used to handle these potential emissions, gas flaring, and reduced emissions “green” completions. The use of flaring and reduced emission completions reduce the levels of actual fugitive emissions from shale well completion operations to about 216 GgCH4, or 50 Mg CH4 per well, a release substantially lower than several widely quoted estimates. Although fugitive emissions from the overall natural gas sector are a proper concern, it is incorrect to suggest that shale gas-related hydraulic fracturing has substantially altered the overall GHG intensity of natural gas production.
 

Estimates of greenhouse gas (GHG) emissions from shale gas production and use are controversial. Here we assess the level of GHG emissions from shale gas well hydraulic fracturing operations in the United States during 2010. Data from each of the approximately 4000 horizontal shale gas wells brought online that year are used to show that about 900 Gg CH4 of potential fugitive emissions were generated by these operations, or 228 Mg CH4 per well—a figure inappropriately used in analyses of the GHG impact of shale gas. In fact, along with simply venting gas produced during the completion of shale gas wells, two additional techniques are widely used to handle these potential emissions: gas flaring and reduced emission ‘green’ completions. The use of flaring and reduced emission completions reduce the levels of actual fugitive emissions from shale well completion operations to about 216 Gg CH4, or 50 Mg CH4 per well, a release substantially lower than several widely quoted estimates. Although fugitive emissions from the overall natural gas sector are a proper concern, it is incorrect to suggest that shale gas-related hydraulic fracturing has substantially altered the overall GHG intensity of natural gas production.

© 2012 the authors

The United States has adopted fuel economy standards that require increases in the on-road efficiency of new passenger vehicles, with the goal of reducing petroleum use and (more recently) greenhouse gas (GHG) emissions. Understanding the cost and effectiveness of fuel economy standards, alone and in combination with economy-wide policies that constrain GHG emissions, is essential to inform coordinated design of future climate and energy policy. We use a computable general equilibrium model, the MIT Emissions Prediction and Policy Analysis (EPPA) model, to investigate the effect of combining a fuel economy standard with an economy-wide GHG emissions constraint in the United States. First, a fuel economy standard is shown to be at least six to fourteen times less cost effective than a price instrument (fuel tax) when targeting an identical reduction in cumulative gasoline use. Second, when combined with a cap-and-trade (CAT) policy, a binding fuel economy standard increases the cost of meeting the GHG emissions constraint by forcing expensive reductions in passenger vehicle gasoline use, displacing more cost-effective abatement opportunities. Third, the impact of adding a fuel economy standard to the CAT policy depends on the availability and cost of abatement opportunities in transport—if advanced biofuels provide a cost-competitive, lowcarbon alternative to gasoline, the fuel economy standard does not bind and the use of lowcarbon fuels in passenger vehicles makes a significantly larger contribution to GHG emissions abatement relative to the casewhen biofuels are not available. This analysis underscores the potentially large costs of a fuel economy standard relative to alternative policies aimed at reducing petroleumuse and GHG emissions. It further emphasizes the need to consider sensitivity to vehicle technology and alternative fuel availability and costs as well as economy-wide responses when forecasting the energy, environmental, and economic outcomes of policy combinations.

© 2013 Elsevier B.V.

The specification of parameters is a crucial task in the development of economic models. The objective of this paper is to improve the standard parameter specification of computable general equilibrium (CGE) models. On that account, we illustrate how Optimal Fingerprint Detection Methods (OFDM) can be used to identify appropriate values for various parameters. These methods originate from climate science and combine a simple model validation exercise with a structured sensitivity analysis. The new approach has three main benefits: 1) It uses a structured optimisation procedure and does not revert to ad-hoc model improvements. 2) It accounts for uncertainty in parameter estimates by using information on the distribution of parameter estimates from the literature. 3) It can be applied for the specification of a range of parameters required in CGE models; for example, for the definition of elasticities or productivity growth rates.

We estimate the potential synergy between pollution and climate control in the U.S. and China, summarizing the results as emissions cross-elasticities of control. We set a range of NOx and SO2 targets, and record the ancillary reduction in CO2 to calculate the percentage change in CO2 divided by the percentage change in NOx (SO2) denoted as ECO2,NOx (ECO2,SO2). Then we conduct the opposite experiment, setting targets for CO2 and recording the ancillary reduction in NOx and SO2 to compute ENOx,CO2 and ESO2,CO2. For ECO2,NOx and ECO2,SO2 we find low values (0.06"’0.23) in both countries with small (10%) reduction targets that rise to 0.40"’0.67 in the U.S. and 0.83"’1.03 in China when targets are more stringent (75% reduction). This pattern reflects the availability of pollution control to target individual pollutants for smaller reductions but the need for wholesale change toward non-fossil technologies when large reductions are required. We trace the especially high cross elasticities in China to its higher dependence on coal. These results are promising in that China may have more incentive to greatly reduce SO2 and NOx with readily apparent pollution benefits in China, that at the same time would significantly reduce CO2 emissions. The majority of existing studies have focused on the effect of CO2 abatement on other pollutants, typically finding strong cross effects. We find similar strong effects but with less dependence on the stringency of control, and stronger effects in the U.S. than in China.

In this study, we estimate potential synergy between pollution and climate control in the U.S. and China and conduct a cross-country comparison. When measured as cross-emissions elasticity, ancillary CO2 abatement from unit % reduction of NOx and SO2 emissions is substantially greater in China under stringent targets, though comparable between the two countries under moderate targets. In contrast, NOx and SO2 abatement from unit % reduction of CO2 emissions is much greater in the U.S. than in China, regardless of the stringency of the policy shock. These results are primarily driven by China’s higher dependence on coal, as coal has larger unit emission-reduction effects than other fossil fuels and its intensive use creates more room for less costly fuel-switching and abatement options. In addition, pollution-abatement co-benefits of carbon mitigation tend to be greater than carbon-mitigation co-benefits of NOx and SO2 reduction in the U.S., while the opposite is the case for China. The relatively low pollution-abatement effects of carbon mitigation policy in China are primarily due to the expanded role of carbon capture and storage technology, which keeps coal from being crowded out of the energy market by reducing its carbon emission factors, but without affecting NOx and SO2 emissions. Our study suggests that some countries like China may consider it more appealing to pursue the synergy from a pollution-control perspective than from a carbon-mitigation standpoint, given the former’s greater synergistic effects. In this sense, future co-benefit studies need to pay more attention to carbon co-benefits of pollution abatement—the opposite logic of the currently dominant focus.

Effectively balancing existing technology adoption and new technology development is critical for successfully managing carbon dioxide (CO2) emissions from the fossil-dominated electric power generation sector. The long infrastructure lifetimes of power plant investments mean that deployment decisions made today will influence carbon dioxide emissions long into the future. New technology development and R&D decisions can help reduce the overall costs of reducing emissions, but there are multiple technology investments to choose from, and returns to R&D are inherently uncertain. These features of the technology “deployment versus development” question create unique challenges for decision makers charged with managing cumulative carbon dioxide emissions from the electricity sector.

Unfortunately, current quantitative decision-support tools ultimately lack one or more of three overarching features jointly necessary to provide useful insights about an optimal balance between R&D program and power plant investments. They lack (1) resolution of the critical structure of the electricity sector, (2) an explicit endogenous representation of the effects of learning-by-searching technological change, and/or (3) an efficient decision-analytic framework to explore multiple technology investment options under uncertainty in the returns to R&D.

This dissertation presents a new quantitative decision-support framework that allows for the study of socially optimal R&D and capital investment decisions for the power generation sector. Through a novel integration of classical electricity generation investment planning methods, economic modeling of endogenous R&D-driven technological change, and emerging numerical stochastic optimization techniques, the new framework (1) explicitly accounts for the complementary roles that generating technologies play within the electric power system, (2) considers the characteristics of the uncertainty in the technology innovation process, and (3) identifies flexible, adaptive R&D investment strategies for multiple technologies for decision makers to consider.

A series of numerical experiments with the new model reveal that (1) the optimal near-term R&D investment strategy under technological change uncertainty and adapting between decisions can be different than the optimal strategy assuming perfect foresight, and may be higher or lower; (2) the timing that a technology should be deployed to meet a specific carbon target dictates the direction and magnitude of the difference in these decisions; (3) increasing the level of uncertainty tends to increase near-term R&D investments; and (4) increasing right-skewness of the uncertainty (i.e., decreasing the likelihood of higher than average returns), reduces R&D spending throughout the planning horizon.

[Link to "Full Document" provides the abstract only; link to full thesis is forthcoming.]

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