Experience with Carbon Taxes and Greenhouse Gas Emissions Trading Systems

Carbon taxes and emissions trading systems (ETSs) to limit emissions of greenhouse gases (GHGs) are increasingly common. At the end of 2015, 17 GHG ETSs were operational in 55 jurisdictions, and 18 jurisdictions collected at least one carbon tax. This paper assesses the performance of carbon taxes and ETSs with respect to environmental effectiveness (reduction of emissions regulated by the instrument), cost-effectiveness (marginal abatement cost), economic efficiency, public finance, and administrative issues. Data on emissions subject to carbon taxes are rarely reported. We estimate the taxed emissions for 17 taxes in 12 jurisdictions from 1991 through the end of 2015. All 17 taxes have reduced emissions relative to business-as-usual. Six of the jurisdictions actually reduced emissions, although in at least three of those jurisdictions the reductions appear to be due to other policies. The small sizes of reduction in almost all 17 cases are partially due to the low tax rates; the modest and uncertain changes in tax rates over time; and the limited response of taxed sources, such as fossil fuels, to price changes. Actual emissions declined for at least six of 10 ETSs. Other policies and developments, such as the 2009 recession, contributed to the reductions, but estimates of the share of the reduction attributable to the instrument are rare. All of the ETSs have accumulated banks of surplus allowances and most have implemented measures to reduce these banks. On average, the marginal cost of compliance is substantially lower for ETSs than carbon taxes. ETS experience has been shared bilaterally and via dedicated institutions. As a result, most ETSs have increased the share of allowances auctioned; adopted declining emissions caps; specified future caps and floor prices several years into the future; shifted to benchmarking for free allowance allocations to emissions-intensive, trade-exposed (EITE) sources; reduced accessibility to foreign offset credits; and established market stability reserves. By contrast, there is little evidence of shared learning and virtually no change to the design of carbon taxes. We found no jurisdiction that routinely tracks the taxed emissions. Very few jurisdictions regularly assess the effectiveness of the tax in achieving emission reductions. Additionally, adjustments to the tax rate often are unpredictable after an introductory period of three to five years. Both instruments reduce emissions, but ETSs have performed better than carbon taxes on the principal criteria of environmental effectiveness and cost-effectiveness. Many jurisdictions have implemented both a carbon tax and a GHG ETS, and every jurisdiction that has adopted either instrument has also implemented other policies. More research is needed to improve the design of both instruments and their interaction with non-market-based carbon policies because the use of multiple instruments produces complex interactive and distributional effects. While economically inefficient, market-based policies should be supplemented by non-market-based policies to ensure sustained political support

Millimeter wave satellite concepts. Volume 1: Executive summary

The objectives of the program were: (1) development of methodology based on the technical requirements of potential services that might be assigned to millimeter wave bands for identifying the viable and appropriate technologies for future NASA millimeter research and development programs, and (2) testing of this methodology with user applications and services. The scope of the program included the entire communications network, both ground and space subsystems. The reports include: (1) cost, weight, and performance models for the subsystems, (2) conceptual design for point-to-point and broadcast communications satellites, (3) analytic relationships between subsystem parameters and an overall link performance, (4) baseline conceptual systems, (5) sensitivity studies, (6) model adjustment analyses, (7) identification of critical technologies and their risks, (8) brief R&D program scenarios for the technologies judged to be moderate or extensive risks

Role of parathyroid hormone therapy in reversing radiation‐induced nonunion and normalization of radiomorphometrics in a murine mandibular model of distraction osteogenesis

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/101851/1/hed23216.pd

The effect of Mg location on Co-Mg-Ru/gamma-Al2O3 Fischer-Tropsch catalysts

The effectiveness of Mg as a promoter of Co-Ru/γ-Al(2)O(3) Fischer–Tropsch catalysts depends on how and when the Mg is added. When the Mg is impregnated into the support before the Co and Ru addition, some Mg is incorporated into the support in the form of Mg(x)Al(2)O(3+x) if the material is calcined at 550°C or 800°C after the impregnation, while the remainder is present as amorphous MgO/MgCO(3) phases. After subsequent Co-Ru impregnation Mg(x)Co(3−x)O(4) is formed which decomposes on reduction, leading to Co(0) particles intimately mixed with Mg, as shown by high-resolution transmission electron microscopy. The process of impregnating Co into an Mg-modified support results in dissolution of the amorphous Mg, and it is this Mg which is then incorporated into Mg(x)Co(3−x)O(4). Acid washing or higher temperature calcination after Mg impregnation can remove most of this amorphous Mg, resulting in lower values of x in Mg(x)Co(3−x)O(4). Catalytic testing of these materials reveals that Mg incorporation into the Co oxide phase is severely detrimental to the site-time yield, while Mg incorporation into the support may provide some enhancement of activity at high temperature

Calculations of collisions between cold alkaline earth atoms in a weak laser field

We calculate the light-induced collisional loss of laser-cooled and trapped magnesium atoms for detunings up to 50 atomic linewidths to the red of the ^1S_0-^1P_1 cooling transition. We evaluate loss rate coefficients due to both radiative and nonradiative state-changing mechanisms for temperatures at and below the Doppler cooling temperature. We solve the Schrodinger equation with a complex potential to represent spontaneous decay, but also give analytic models for various limits. Vibrational structure due to molecular photoassociation is present in the trap loss spectrum. Relatively broad structure due to absorption to the Mg_2 ^1Sigma_u state occurs for detunings larger than about 10 atomic linewidths. Much sharper structure, especially evident at low temperature, occurs even at smaller detunings due to of Mg_2 ^1Pi_g absorption, which is weakly allowed due to relativistic retardation corrections to the forbidden dipole transition strength. We also perform model studies for the other alkaline earth species Ca, Sr, and Ba and for Yb, and find similar qualitative behavior as for Mg.Comment: 20 pages, RevTex, 13 eps figures embedde

Spitzer Sage Survey of the Large Magellanic Cloud. III. Star Formation and ~1000 New Candidate Young Stellar Objects

We present ~1000 new candidate Young Stellar Objects (YSOs) in the Large Magellanic Cloud selected from Spitzer Space Telescope data, as part of the Surveying the Agents of a Galaxy's Evolution (SAGE) Legacy program. The YSOs, detected by their excess infrared (IR) emission, represent early stages of evolution, still surrounded by disks and/or infalling envelopes. Previously, fewer than 20 such YSOs were known. The candidate YSOs were selected from the SAGE Point Source Catalog from regions of color-magnitude space least confused with other IR-bright populations. The YSOs are biased toward intermediate- to high-mass and young evolutionary stages, because these overlap less with galaxies and evolved stars in color-magnitude space. The YSOs are highly correlated spatially with atomic and molecular gas, and are preferentially located in the shells and bubbles created by massive stars inside. They are more clustered than generic point sources, as expected if star formation occurs in filamentary clouds or shells. We applied a more stringent color-magnitude selection to produce a subset of "high-probability" YSO candidates. We fitted the spectral-energy distributions (SEDs) of this subset and derived physical properties for those that were well fitted. The total mass of these well-fitted YSOs is ~2900 M_☉ and the total luminosity is ~2.1 × 10^6 L_☉ . By extrapolating the mass function with a standard initial mass function and integrating, we calculate a current star-formation rate of ~0.06 M_☉ yr^(–1), which is at the low end of estimates based on total ultraviolet and IR flux from the galaxy (~0.05 – 0.25 M_☉ yr^(–1)), consistent with the expectation that our current YSO list is incomplete. Follow-up spectroscopy and further data mining will better separate the different IR-bright populations and likely increase the estimated number of YSOs. The full YSO list is available as electronic tables, and the SEDs are available as an electronic figure for further use by the scientific community

Probing the Origins of the CIV and Fe Kalpha Baldwin Effect

We use UV/optical and X-ray observations of 272 radio-quiet Type 1 AGNs and quasars to investigate the CIV Baldwin Effect (BEff). The UV/optical spectra are drawn from the Hubble Space Telescope, International Ultraviolet Explorer and Sloan Digital Sky Survey archives. The X-ray spectra are from the Chandra and XMM-Newton archives. We apply correlation and partial-correlation analyses to the equivalent widths, continuum monochromatic luminosities, and alpha_ox, which characterizes the relative X-ray to UV brightness. The equivalent width of the CIV 1549 emission line is correlated with both alpha_ox and luminosity. We find that by regressing l_UV with EW(CIV) and alpha_ox, we can obtain tighter correlations than by regressing l_UV with only EW(CIV). Both correlation and regression analyses imply that l_UV is not the only factor controlling the changes of EW(CIV); alpha_ox (or, equivalently, the soft X-ray emission) plays a fundamental role in the formation and variation of CIV. Variability contributes at least 60% of the scatter of the EW(CIV)-l_UV relation and at least 75% of the scatter of the of the EW(CIV)-alpha_ox relation. In our sample, narrow Fe Kalpha 6.4 keV emission lines are detected in 50 objects. Although narrow Fe Kalpha exhibits a BEff similar to that of CIV, its equivalent width has almost no dependence on either alpha_ox or EW(CIV). This suggests that the majority of narrow Fe Kalpha emission is unlikely to be produced in the broad emission-line region. We do find suggestive correlations between the emission-line luminosities of CIV and Fe Kalpha, which could be potentially used to estimate the detectability of the Fe Kalpha line of quasars from rest-frame UV spectroscopic observations

Black Hole Mass Estimates Based on CIV are Consistent with Those Based on the Balmer Lines

Using a sample of high-redshift lensed quasars from the CASTLES project with observed-frame ultraviolet or optical and near-infrared spectra, we have searched for possible biases between supermassive black hole (BH) mass estimates based on the CIV, Halpha and Hbeta broad emission lines. Our sample is based upon that of Greene, Peng & Ludwig, expanded with new near-IR spectroscopic observations, consistently analyzed high S/N optical spectra, and consistent continuum luminosity estimates at 5100A. We find that BH mass estimates based on the FWHM of CIV show a systematic offset with respect to those obtained from the line dispersion, sigma_l, of the same emission line, but not with those obtained from the FWHM of Halpha and Hbeta. The magnitude of the offset depends on the treatment of the HeII and FeII emission blended with CIV, but there is little scatter for any fixed measurement prescription. While we otherwise find no systematic offsets between CIV and Balmer line mass estimates, we do find that the residuals between them are strongly correlated with the ratio of the UV and optical continuum luminosities. Removing this dependency reduces the scatter between the UV- and optical-based BH mass estimates by a factor of approximately 2, from roughly 0.35 to 0.18 dex. The dispersion is smallest when comparing the CIV sigma_l mass estimate, after removing the offset from the FWHM estimates, and either Balmer line mass estimate. The correlation with the continuum slope is likely due to a combination of reddening, host contamination and object-dependent SED shapes. When we add additional heterogeneous measurements from the literature, the results are unchanged.Comment: Accepted for publication in The Astrophysical Journal. 37 text pages + 8 tables + 23 figures. Updated with comments by the referee and with a expanded discussion on literature data including new observation

Using global analysis, partial specifications, and an extensible assertion language for program validation and debugging

We discuss a framework for the application of abstract interpretation as an aid during program development, rather than in the more traditional application of program optimization. Program validation and detection of errors is first performed statically by comparing (partial) specifications written in terms of assertions against information obtained from (global) static analysis of the program. The results of this process are expressed in the user assertion language. Assertions (or parts of assertions) which cannot be checked statically are translated into run-time tests. The framework allows the use of assertions to be optional. It also allows using very general properties in assertions, beyond the predefined set understandable by the static analyzer and including properties defined by user programs. We also report briefly on an implementation of the framework. The resulting tool generates and checks assertions for Prolog, CLP(R), and CHIP/CLP(fd) programs, and integrates compile-time and run-time checking in a uniform way. The tool allows using properties such as types, modes, non-failure, determinacy, and computational cost, and can treat modules separately, performing incremental analysis

The ideal healthcare: priorities of people with chronic conditions and their carers

Background It is well established that health consumer opinions should be considered in the design, delivery, and evaluation of health services. However, the opinions of people with chronic conditions and their carers and what they actually consider as ideal healthcare is limited. The aim of this study is to investigate the healthcare priorities of consumers with chronic conditions and their carers, if there are differences between these two groups, and if priorities differ depending on geographical location. Methods The nominal group technique was used as a method to identify what is currently important to, or valued by, participants. This method was also particularly suited to learning about healthcare problems and generating important solutions, thereby helping to bridge the gap between research and policy. Recruitment was carried out via purposive sampling, with the assistance of community pharmacies, general practices, various health agencies, government and non-government organisations. A total of 11 nominal groups were conducted; five groups consisted predominantly of consumers (n = 33 participants), two groups consisted predominantly of carers (n = 12 participants) and four were mixed groups, i.e. consumers, carers, and both (n = 26 participants). Results The findings suggested that to create a model of ideal healthcare for people with chronic conditions and their carers, appropriate and timely healthcare access was of paramount importance. Continuity and coordinated care, patient-centred care and affordability were equally the second most important healthcare priorities for all groups. When compared with other groups, access was discussed more frequently among participants residing in the rural area of Mount Isa. Compared to consumers, carers also discussed priorities that were more reminiscent with their caring roles, such as increased access and continuity and coordinated care. Conclusions Access to healthcare is the most important priority for people with chronic conditions and their carers. In the event of inappropriate access for certain groups, all other efforts to increase the quality of healthcare delivery, e.g. patient-centred care, may be pointless. However, health professionals alone may be limited in their ability to address the concerns related to healthcare access; structural changes by health policy makers may be needed