Linkage of Tradable Permit Systems in International Climate Policy Architecture

Cap-and-trade systems have emerged as the preferred national and regional instrument for reducing emissions of greenhouse gases throughout the industrialized world, and the Clean Development Mechanism — an international emission-reduction-credit system — has developed a substantial constituency, despite some concerns about its performance. Because linkage between tradable permit systems can reduce compliance costs and improve market liquidity, there is great interest in linking cap-and-trade systems to each other, as well as to the CDM and other credit systems. We examine the benefits and concerns associated with various types of linkages, and analyze the near-term and long-term role that linkage may play in a future international climate policy architecture. In particular, we evaluate linkage in three potential roles: as an independent bottom-up architecture, as a step in the evolution of a top-down architecture, and as an ongoing element of a larger climate policy agreement. We also assess how the policy elements of climate negotiations can facilitate or impede linkages. Our analysis throughout is both positive and normative.Linkage, Cap-and-Trade, Tradable Permits, Global Climate Change

Too Good to Be True? An Examination of Three Economic Assesssments of California Climate Change Policy

California's Global Warming Solutions Act of 2006 limits California's greenhouse gas (GHG) emissions in 2020 to their 1990 level. Global climate change is a pressing environmental problem, and the best possible public policies will be required to address it. Therefore, analyses of prospective policies must themselves be of high quality, so that policymakers can reasonably rely on them when making the critical decisions they inevitably will face. In 2006, three studies were released indicating that California can meet its 2020 target at no net economic cost , raising questions about whether opportunities truly exist to substantially reduce emissions at no cost, or whether studies reaching such conclusions may simply severely underestimate costs. This paper provides an evaluation of these three California studies. We find that although opportunities may exist for some no-cost emission reductions, these California studies substantially underestimate the cost of meeting California's 2020 target. The studies underestimate costs by omitting important components of the costs of emission reduction efforts, and by overestimating offsetting savings that some of those efforts yield through improved energy efficiency. In some cases, the studies focus on the costs of particular actions to reduce emissions, but fail to consider the effectiveness and costs of policies that would be necessary to bring about such actions. While quantifying the full extent of the resulting cost underestimation is beyond the scope of our study, the underestimation is clearly economically significant. A few of the identified flaws individually lead to underestimation of annual costs on the order of billions of dollars. Hence, these studies do not offer reliable estimates of the cost of meeting California's 2020 target. Better analyses are needed to inform policymakers. While the Global Warming Solutions Act of 2006 sets a 2020 emissions target, critical policy design decisions remain to be made that will fundamentally affect the cost of California's climate policy. For example, policymakers must determine emission targets for the years before and after 2020, the emission sources that will be regulated to meet those targets, and the policy instruments that will be employed. The California studies do not directly address the cost implications of these and other policy design decisions, and their overly optimistic findings may leave policymakers with an inadequate appreciation of the stakes associated with decisions that lie ahead. As such, California would benefit from studies that specifically assess the cost implications of alternative policy designs. Nonetheless, a careful evaluation of the California studies highlights some important policy design lessons that apply regardless of the extent to which no-cost emission reduction opportunities actually exist. In particular, policies should be designed to account for uncertainty regarding emission reduction costs, much of which will not be resolved before policies must be enacted. Also, consideration of the different market failures that lead to excessive GHG emissions makes clear that to reduce emissions cost-effectively, policymakers should adopt a market-based policy (such as a cap-and-trade system) as the core policy instrument. The presence of specific market failures that may lead to some no-cost emission reduction opportunities suggests the potential value of additional policies that act as complements, rather than alternatives, to a market-based policy. However, to develop complementary policies that efficiently target such no-cost opportunities, policymakers need better information than currently exists regarding the specific market failures that bring about those opportunities.

Linking a U.S. Cap-and-Trade System for Greenhouse Gas Emissions: Opportunities, Implications, and Challenges

The long-run cost of a U.S. cap-and-trade system for greenhouse gas (GHG) emissions could be significantly reduced by linking that system with other existing and emerging tradable permit systems for GHG emissions. However, along with the cost savings that it offers, linking carries with it other implications. For example, linking has distributional consequences and, under some circumstances, linked systems collectively will not achieve the same level of emission reductions as they would absent linking. Also, linking can reduce a government's control over the impacts of its tradable permit system. Thus, in considering linkages, the United States and potential linking partners may have to weigh linking's implications for potentially competing policy objectives, much as will be required in developing other elements of their respective domestic climate policies. Because linking's implications depend on the type of link that is established and the specific characteristics and design of the linked systems, in the near-term, some links will be more attractive and easier to establish than others. Importantly, those links that may be the easiest to establish - links with emission reduction credit systems such as the Clean Development Mechanism - likely can provide much of the near-term cost-saving and risk-diversifying advantages that linking can offer. Given the implications of links with other cap-and-trade systems, to facilitate such links, it may be necessary to harmonize certain elements of the design of the U.S. system and any system(s) with which it links. In particular, agreement on a unified set of measures to address cost uncertainty likely will be a necessary pre-condition for an unrestricted link with another cap-and-trade system. Also, in order to link with other cap-and-trade systems, it may be necessary to establish broader international agreements governing aspects of the design of the U.S. and linked systems beyond simply mutual recognition of allowances.

Too Good to Be True? Three Economic Assessments of California Climate Change Policy

California’s Global Warming Solutions Act of 2006 limits California’s greenhouse gas (GHG) emissions in 2020 to their 1990 level. Global climate change is a pressing environmental problem, and the best possible public policies will be required to address it. Therefore, analyses of prospective policies must themselves be of high quality, so that policymakers can reasonably rely on them when making the critical decisions they inevitably will face. In 2006, three studies were released indicating that California can meet its 2020 target at no net economic cost — raising questions about whether opportunities truly exist to substantially reduce emissions at no cost, or whether studies reaching such conclusions may simply severely underestimate costs. This paper provides an evaluation of these three California studies. We find that although opportunities may exist for some no-cost emission reductions, these California studies substantially underestimate the cost of meeting California’s 2020 target. The studies underestimate costs by omitting important components of the costs of emission reduction efforts, and by overestimating offsetting savings that some of those efforts yield through improved energy efficiency. In some cases, the studies focus on the costs of particular actions to reduce emissions, but fail to consider the effectiveness and costs of policies that would be necessary to bring about such actions. While quantifying the full extent of the resulting cost underestimation is beyond the scope of our study, the underestimation is clearly economically significant. A few of the identified flaws individually lead to underestimation of annual costs on the order of billions of dollars. Hence, these studies do not offer reliable estimates of the cost of meeting California’s 2020 target. Better analyses are needed to inform policymakers. While the Global Warming Solutions Act of 2006 sets a 2020 emissions target, critical policy design decisions remain to be made that will fundamentally affect the cost of California’s climate policy. For example, policymakers must determine emission targets for the years before and after 2020, the emission sources that will be regulated to meet those targets, and the policy instruments that will be employed. The California studies do not directly address the cost implications of these and other policy design decisions, and their overly optimistic findings may leave policymakers with an inadequate appreciation of the stakes associated with decisions that lie ahead. As such, California would benefit from studies that specifically assess the cost implications of alternative policy designs.Nonetheless, a careful evaluation of the California studies highlights some important policy design lessons that apply regardless of the extent to which no-cost emission reduction opportunities actually exist. In particular, policies should be designed to account for uncertainty regarding emission reduction costs, much of which will not be resolved before policies must be enacted. Also, consideration of the different market failures that lead to excessive GHG emissions makes clear that to reduce emissions cost-effectively, policymakers should adopt a market-based policy (such as a cap-and-trade system) as the core policy instrument. The presence of specific market failures that may lead to some no-cost emission reduction opportunities suggests the potential value of additional policies that act as complements, rather than alternatives, to a market-based policy. However, to develop complementary policies that efficiently target such no-cost opportunities, policymakers need better information than currently exists regarding the specific market failures that bring about those opportunities.

Subcellular organization of UBE3A in human cerebral cortex.

BackgroundLoss of UBE3A causes Angelman syndrome, whereas excess UBE3A activity appears to increase the risk for autism. Despite this powerful association with neurodevelopmental disorders, there is still much to be learned about UBE3A, including its cellular and subcellular organization in the human brain. The issue is important, since UBE3A's localization is integral to its function.MethodsWe used light and electron microscopic immunohistochemistry to study the cellular and subcellular distribution of UBE3A in the adult human cerebral cortex. Experiments were performed on multiple tissue sources, but our results focused on optimally preserved material, using surgically resected human temporal cortex of high ultrastructural quality from nine individuals.ResultsWe demonstrate that UBE3A is expressed in both glutamatergic and GABAergic neurons, and to a lesser extent in glial cells. We find that UBE3A in neurons has a non-uniform subcellular distribution. In somata, UBE3A preferentially concentrates in euchromatin-rich domains within the nucleus. Electron microscopy reveals that labeling concentrates in the head and neck of dendritic spines and is excluded from the PSD. Strongest labeling within the neuropil was found in axon terminals.ConclusionsBy highlighting the subcellular compartments in which UBE3A is likely to function in the human neocortex, our data provide insight into the diverse functional capacities of this E3 ligase. These anatomical data may help to elucidate the role of UBE3A in Angelman syndrome and autism spectrum disorder

Habitual Behavior Is Mediated by a Shift in Response-Outcome Encoding by Infralimbic Cortex

The ability to flexibly switch between goal-directed actions and habits is critical for adaptive behavior. The infralimbic prefrontal cortex (IfL-C) has been consistently identified as a crucial structure for the regulation of response strategies. To investigate the role of the IfL-C, the present study employed two validated reinforcement schedules that either promote habits or goal-directed actions in mice. The results reveal that information about action-outcome relationships is differentially encoded in the IfL-C during actions and habits as evidenced by encoding of behavioral outcomes during goal-directed actions that is lost during habits. Optogenetic inhibition of the IfL-C selectively at press during habitual behavior (when firing rates are reduced during unreinforced goal-directed actions) resulted in restoration of sensitivity to change of action-outcome contingency. These results reveal a novel functional mechanism by which IfL-C promotes habitual behavior, and provide insight into strategies for the treatment and prevention of pathological, inflexible behavior common in neuropsychiatric illness

Theory of selective excitation in Stimulated Raman Scattering

A semiclassical model is used to investigate the possibility of selectively exciting one of two closely spaced, uncoupled Raman transitions. The duration of the intense pump pulse that creates the Raman coherence is shorter than the vibrational period of a molecule (impulsive regime of interaction). Pulse shapes are found that provide either enhancement or suppression of particular vibrational excitations.Comment: RevTeX4,10 pages, 5 figures, submitted to Phys.Rev.

Observation of coherent transients in ultrashort chirped excitation of an undamped two-level system

The effects of Coherent excitation of a two level system with a linearly chirped pulse are studied theoretically and experimentally (in Rb (5s - 5p)) in the low field regime. The Coherent Transients are measured directly on the excited state population on an ultrashort time scale. A sharp step corresponds to the passage through resonance. It is followed by oscillations resulting from interferences between off-resonant and resonant contributions. We finally show the equivalence between this experiment and Fresnel diffraction by a sharp edge.Comment: 4 pages, 4 figures, to appear in PR

Transform-limited pulses are not optimal for resonant multiphoton transitions

Maximizing nonlinear light-matter interactions is a primary motive for compressing laser pulses to achieve ultrashort transform limited pulses. Here we show how, by appropriately shaping the pulses, resonant multiphoton transitions can be enhanced significantly beyond the level achieved by maximizing the pulse's peak intensity. We demonstrate the counterintuitive nature of this effect with an experiment in a resonant two-photon absorption, in which, by selectively removing certain spectral bands, the peak intensity of the pulse is reduced by a factor of 40, yet the absorption rate is doubled. Furthermore, by suitably designing the spectral phase of the pulse, we increase the absorption rate by a factor of 7.Comment: 4 pages, 3 figure