946 research outputs found
New results on the influence of climate on the distribution of population and economic activity
This paper applies G-Econ+, an updated version of the G-Econ database by Nordhaus, to analyze the influence of climatic and geographic factors on the geographic distribution of population and economic activity. I discuss options for improved treatment of several statistical problems associated with G-Econ, which are not addressed adequately in the original G-Econ analysis. Reanalysis of key results from the original G-Econ analysis corrects some surprising results therein. Extensive sensitivity analysis determines the robustness of the relationship between climatic factors and economic activity across alternative central estimators. Further analysis assesses revealed climatic preferences of population, the effects of climate parameters on different quantiles of economic variables, and synergies between temperature and precipitation. I find that population density has a much stronger influence on output density than output per capita. Furthermore, least developed countries are located in a climatic zone where all indicators of economic activity decline with increasing temperature.Climate; macroeconomics; population; cross-sectional analysis; G-Econ
Global maps of climate change impacts on the favourability for human habitation and economic activity
This paper analyzes the statistical relationship between climatic factors and the global distribution of population and economic activity. Building on this analysis, a new method is developed for assessing geographically explicit impacts of climate change on the suitability of regions for human habitation and economic activity. This method combines information about differences in the conditional distributions of population density and economic activity across climate categories with climate change projections from an ensemble of general circulation models. In contrast to other cross-sectional analyses of the economic impacts of climate change, the method applied here does not require specific assumptions about the functional form of the relationship between climatic and non-climatic factors on the one hand, and population density and economic activity on the other. The results indicate that climate change will improve the habitability of some scarcely populated regions, in particular in Canada, Scandinavia, Russia, Mongolia, northern China, Tibet, and parts of Central Asia, but it will impair the habitability of many densely populated regions in the eastern USA, southern Europe, northern and southern Africa, eastern China, and parts of Australia. Most parts of India, South-East Asia and Oceania, Central America and northern South America, the Sahara and the Sahel are projected to experience climatic conditions during this century that have no geographical analogue in the present climate. Hence, a large majority of the world’s population is living in regions whose habitability is either projected to decrease or that are projected to experience globally unprecedented climate conditions within this century under a business-as-usual emissions scenario.Climate change; macroeconomics; population; cross-sectional analysis
2010 Nebraska Population by Sex and Five-Year Age Group: Non-White or Hispanic /Lati no (Minority Population)
Source: 2010 Census (SF1: P12 and P12I), U.S. CensusBurea
Mutual Unbiasedness in Coarse-grained Continuous Variables
The notion of mutual unbiasedness for coarse-grained measurements of quantum
continuous variable systems is considered. It is shown that while the procedure
of "standard" coarse graining breaks the mutual unbiasedness between conjugate
variables, this desired feature can be theoretically established and
experimentally observed in periodic coarse graining. We illustrate our results
in an optics experiment implementing Fraunhofer diffraction through a periodic
diffraction grating, finding excellent agreement with the derived theory. Our
results are an important step in developing a formal connection between
discrete and continuous variable quantum mechanics.Comment: 5 pages, 3 figures + Supplemental Material (1 page) v2: Introduction
expanded, minor typos correcte
The erosion behaviour of pure tungsten electrodes in Gas Tungsten Arc Welding (GTAW)
A cross-time study has been made on the erosion behaviour of Gas-Tungsten Arc Welding (GTAW) for pure tungsten electrode. Its behaviour during arcing was analyzed and compared from the points of view of metallurgical changes in electrode due to long-term operation. Metallographic studies of the electrodes indicate that the crack formation and grain growth during periodic temperature variations. These observations are discussed theoretically based on the experimental results and the thermal expansion parameters of Tungsten
Climate system modeling in the framework of the tolerable windows approach: The ICLIPS climate model
The computational burden associated with applications of theTolerable Windows Approach (TWA) considerably exceeds that oftraditional integrated assessments of global climate change. Aspart of the ICLIPS (Integrated Assessment of Climate ProtectionStrategies) project, a computationally efficient climate model hasbeen developed that can be included in integrated assessmentmodels of any kind. The ICLIPS climate model (ICM) is implementedin GAMS. It is driven by anthropogenic emissions of CO2,CH4, N2O, halocarbons, SF6, andSO2. Theoutput includes transient patterns of near-surface airtemperature, total column-integrated cloud cover fraction,precipitation, humidity, and global mean sea-level rise. Thecarbon cycle module explicitly treats the nonlinear sea watercarbon chemistry and the nonlinear CO2 fertilized biosphereuptake. Patterns of the impact-relevant climate variables arederived form empirical orthogonal function (EOF) analysis andscaled by the principal component of temperature change. Theevolution of the latter is derived from a box-model-typedifferential analogue to its impulse response function convolutionintegral. We present a description of the ICM components and someresults to demonstrate the model's applicability in the TWA setting
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