6,558 research outputs found

    Against High Interest Rates

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    In the economics of climate change, the future benefits of greenhouse gas emissions abatement are commonly discounted at a rate equal to the long-run return on corporate stocks, which averaged 6% per year during the 20th century. Since a 6% discount rate implies that one dollar of benefits obtained one century from the present attains a present value of less than one cent, this method implies that only modest steps towards greenhouse gas emissions are economically warranted. This chapter critiques this approach to discounting the future based on three distinct lines of reasoning. First, the use of high discount rates is inconsistent with classical utilitarianism, which holds that equal weight should be attached to the welfare of present and future generations. Second, the approach violates the principle of stewardship, which holds that it is morally unjust for present generations to engage in actions that impose uncompensated environmental costs on posterity. Third, the use of a 6% discount rate is appropriate in the analysis of public policies that have risk characteristics that are similar to those associated with corporate stocks. Economic theory, however, suggests that discount rates of 1% or less should be used to evaluate policies that reduce future risks. Since a main objective of climate change policies is to reduce the risks faced by future society, the use of high discount rates in the analysis of climate change policies is arguably inappropriate.

    Interview of Richard B. HOWARTH

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    Greenhouse gas emissions from domestic hot water: heat pumps compared to most commonly used systems

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    We estimate the emissions of the two most important greenhouse gasses (GHG), carbon dioxide (CO2) and methane (CH4), from the use of modern high-efficiency heat pump water heaters compared to the most commonly used domestic hot water systems: natural gas storage tanks, tankless natural gas demand heaters, electric resistance storage tanks, and tankless electric resistance heaters. We considered both natural gas-powered electric plants and coal-powered plants as the source of the electricity for the heat pumps, the thermal electric storage tanks, and the tankless electric demand heaters. The time-integrated radiative forcing associated with using a heat pump water heater was always smaller than any other means of heating water considered in this study across all time frames including at 20 and 100 years. The estimated amount of CH4 lost during its lifecycle was the most critical factor determining the relative magnitude of the climatic impact. The greatest net climatic benefit within the 20-year time frame was predicted to be achieved when a storage natural gas water heater (the most common system for domestic hot water in the United States) fueled by shale gas was replaced with a high efficiency heat pump water heater powered by coal-generated electricity; the heat pump system powered by renewable electricity would have had an even greater climatic benefit, but was not explicitly modeled in this study. Our analysis provides the first assessment of the GHG footprint associated with using a heat pump water heater, which we demonstrate to be an effective and economically viable way of reducing emissions of GHGs.This study was funded by the Wallace Global Fund, the Park Foundation, and Cornell University

    Influential publications in ecological economics revisited

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    We revisit the analysis of Costanza et al. (2004, Ecological Economics) of influential publications in ecological economics to discover what has changed a decade on. We examine which sources have been influential on the field of ecological economics in the past decade, which articles in the journal Ecological Economics have had the most influence on the field and on the rest of science, and on which areas of science the journal is having the most in- fluence.We find that the field has matured over this period, with articles published in the journal having a greater influence than before, an increase in citation links to environmental studies journals, a reduction in citation links to mainstream economics journals, and possibly a shift in themes to a more applied and empirical direction.Copyright Information: © 2016 Elsevier B.V. http://www.sherpa.ac.uk/romeo/issn/0921-8009/..."Authors pre-print on any website, including arXiv and RePEC" from SHERPA/RoMEO site (as at 3/02/16)

    The Price of Snow: Albedo Valuation and a Case Study for Forest Management

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    Several climate frameworks have included the role of carbon storage in natural landscapes as a potential mechanism for climate change mitigation. This has resulted in an incentive to grow and maintain intact long-lived forest ecosystems. However, recent research has suggested that the influence of albedo-related radiative forcing can impart equal and in some cases greater magnitudes of climate mitigation compared to carbon storage in forests where snowfall is common and biomass is slow-growing. While several methodologies exist for relating albedo-associated radiative forcing to carbon storage for the analysis of the tradeoffs of these ecosystem services, they are varied, and they have yet to be contrasted in a case study with implications for future forest management. Here we utilize four methodologies for calculating a shadow price for albedo radiative forcing and apply the resulting eight prices to an ecological and economic forest model to examine the effects on optimal rotation periods on two different forest stands in the White Mountain National Forest in New Hampshire, USA. These pricing methodologies produce distinctly different shadow prices of albedo, varying from a high of 9.36 × 10−4 and a low of 1.75 × 10−5 w1yr1intheinitialyear,toahighof0.019andalowof3.55×104w−1yr−1 in the initial year, to a high of 0.019 and a low of 3.55 × 10−4 w−1yr−1 in year 200 of the simulation. When implemented in the forest model, optimal rotation periods also varied considerably, from a low of 2 to a high of 107 years for a spruce-fir stand and from 35 to 80 years for a maple-beech-birch stand. Our results suggest that the choice of climate metrics and pricing methodologies for use with forest albedo alter albedo prices considerably, may substantially adjust optimal rotation period length, and therefore may have consequences with respect to forest land cover change

    Gender equality and investments in adolescents in the rural Philippines:

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    "...Many studies have looked at the way resources are distributed to men, women, and especially to small children, but one age group within the family has been largely ignored: the adolescents. Adolescence is a crucial period in that teenagers can make major contributions to their families' welfare through their labor and earnings, in and outside the household, but may sacrifice their own wishes and future well-being in the process if such contributions come at the expense of investments in their education. The research methodology in this report, combining regression analysis with ethnography, provides a lesson in how complementarities between methodological approaches can be exploited...The research finds that parents are not unduly influenced by short-term needs and are ready to make substantial sacrifices in terms of current consumption in order to invest in their children's future. The research also concludes that boys and girls in this rural area of the Philippines are generally treated equally, provid ing a contrast with other Asian settings where discrimination by gender is common." (Forward by Per Pinstrup- Andersen)Teenagers Philippines Social conditions., Rural families Philippines., Gender, Health and nutrition, Education Economic aspects Philippines., Household resource allocation, Health.,

    The Influence of Stellar Wind Variability on Measurements of Interstellar O VI Along Sightlines to Early-Type Stars

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    A primary goal of the FUSE mission is to understand the origin of the O VI ion in the interstellar medium of the Galaxy and the Magellanic Clouds. Along sightlines to OB-type stars, these interstellar components are usually blended with O VI stellar wind profiles, which frequently vary in shape. In order to assess the effects of this time-dependent blending on measurements of the interstellar O VI lines, we have undertaken a mini-survey of repeated observations toward OB-type stars in the Galaxy and the Large Magellanic Cloud. These sparse time series, which consist of 2-3 observations separated by intervals ranging from a few days to several months, show that wind variability occurs commonly in O VI (about 60% of a sample of 50 stars), as indeed it does in other resonance lines. However, in the interstellar O VI λ\lambda1032 region, the O VI λ\lambda1038 wind varies only in \sim30% of the cases. By examining cases exhibiting large amplitude variations, we conclude that stellar-wind variability {\em generally} introduces negligible uncertainty for single interstellar O VI components along Galactic lines of sight, but can result in substantial errors in measurements of broader components or blends of components like those typically observed toward stars in the Large Magellanic Cloud. Due to possible contamination by discrete absorption components in the stellar O VI line, stars with terminal velocities greater than or equal to the doublet separation (1654 km/s) should be treated with care.Comment: Accepted for publication in the Astrophysical Journal Lette

    Localization of visually indistinguishable mature lettuce heads using spatial information

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    This paper describes an approach to recognizing and localizing centers of mature lettuce heads in the field when the lettuce leaves obscure the distinctions between plants. This is of great value when using an automatic harvester in cluttered or closely planted vegetation. The aim of this work is to investigate and verify the potential use of spatial rather than visual clues for recognition and localization, with a view to implementing a more robust and sophisticated system if promise is shown. Colour/texture information was difficult to use so spatial information was used instead. A laser range finder was used to generate a height plot from above the plants. Lettuce examples were used to learn the radial distribution of the lettuce model. This was compared with the distributions of arbitrary locations in new scans to locate possible lettuce locations. Planting distance information was then used to localize the final lettuce positions. The algorithm was able to successfully locate 15 out of 16 sample lettuces

    Irreducible Killing Tensors from Third Rank Killing-Yano Tensors

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    We investigate higher rank Killing-Yano tensors showing that third rank Killing-Yano tensors are not always trivial objects being possible to construct irreducible Killing tensors from them. We give as an example the Kimura IIC metric were from two rank Killing-Yano tensors we obtain a reducible Killing tensor and from third rank Killing-Yano tensors we obtain three Killing tensors, one reducible and two irreducible.Comment: 10 page
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