1,105,398 research outputs found
Economic valuation of the impacts of climate change in agriculture in Europe
The objective of this study is to provide a European assessment of the potential effects of climate change on agricultural crop production computing monetary estimates of these impacts for the European agricultural sector. The future scenarios incorporate socio economic projections derived from several SRES scenarios and climate projections obtained from global climate models and regional climate models. The quantitative results are based simulations using the GTAP general equilibrium models system that includes all relevant economic activities. The estimated changes in the exports and imports of agricultural goods, value of GDP and crop prices under the climate and socio-economic scenarios show significant regional differences between northern and southern European countries. The patterns are positive effects except on Mediterranean countries. The most important increases seem to concern the continental region, where the productivity increases enlarge GDP more intensively due to the importance of agricultural sector in the region. The monetary estimates also show that in all cases uncertainty derived from socio-economic scenarios has a larger effect than the ones derived from climate scenarios.agriculture, climate change, computable general equilibrium models, Environmental Economics and Policy,
Development of Future Habitat Suitability Models for the Swift fox (Vulpes velox) in the American Southwest
The Swift fox (Vupes velox) is a habitat specialist species of short or mixed grass prairie. We used bioclimatic envelope models and habitat suitability models under three future climate scenarios (based on CO2 emission rates) from "www.climatewizard.org":http://www.climatewizard.org to fit species distribution models, using the maximum entropy method. Current suitable habitat for the swift fox covers an area of 161,984 km2. Under the future climate scenarios the habitat decreases by 27% in the low emission scenario, 63% for medium emissions, and 53% in the high emissions scenario. This decrease in suitable habitat corresponded to an overall decrease in total grassland landcover. The current total area of grassland is 423,440 km2. Under the future climate scenarios the grassland decreased by 12% in the low emissions scenario, 24% for medium emissions, and 16% in the high emissions scenario
Phenomenological Implications of Deflected Mirage Mediation: Comparison with Mirage Mediation
We compare the collider phenomenology of mirage mediation and deflected
mirage mediation, which are two recently proposed "mixed" supersymmetry
breaking scenarios motivated from string compactifications. The scenarios
differ in that deflected mirage mediation includes contributions from gauge
mediation in addition to the contributions from gravity mediation and anomaly
mediation also present in mirage mediation. The threshold effects from gauge
mediation can drastically alter the low energy spectrum from that of pure
mirage mediation models, resulting in some cases in a squeezed gaugino spectrum
and a gluino that is much lighter than other colored superpartners. We provide
several benchmark deflected mirage mediation models and construct model lines
as a function of the gauge mediation contributions, and discuss their discovery
potential at the LHC.Comment: 29 pages, 9 figure
A Comparison of Mixed-Higgs Scenarios In the NMSSM and the MSSM
We study scenarios in the minimal and next-to minimal supersymmetric models
in which the lightest CP-even Higgs boson can have mass below the 114 GeV
standard model LEP limit by virtue of reduced ZZ coupling due to substantial
mixing among the Higgs bosons. We pay particular attention to the size of
corrections from superpartners needed for these scenarios to be viable and
point to boundary conditions at large scales which lead to these scenarios
while at the same time keeping electroweak fine tuning modest in size. We find
that naturalness of electroweak symmetry breaking in the mixed-Higgs scenarios
of both models points to the same region of soft supersymmetry breaking terms,
namely those leading to large mixing in the stop sector at the electroweak
scale, especially if we also require that the lightest CP-even Higgs explains
the Higgs-like LEP events at about 98 GeV.Comment: 14 pages, 19 figure
Little hierarchy in the minimally specified MSSM
We study constrained versions of the minimal supersymmetric model and
investigate the hierarchy between the electroweak scale and the scale of
superpartners that can be achieved without relying on specifying model
parameters by more than one digit. This approach automatically avoids scenarios
in which a large hierarchy is obtained by special choices of parameters and yet
keeps scenarios that would be otherwise disfavored by various sensitivity
measures. We consider models with universal gaugino and scalar masses, models
with non-universal Higgs masses or non-universal gaugino masses and focus on
scenarios in which all the model parameters are either of the same order or
zero at the grand unification scale. We find that the maximal hierarchy between
the electroweak scale and stop masses, requiring that model parameters are not
specified beyond one digit, ranges from a factor of for the CMSSM
up to for models with non-universal Higgs or gaugino masses.Comment: 17 pages, 4 figures, discussion expanded, matches published versio
Development of scenarios for land cover, population density, impervious cover, and conservation in New Hampshire, 2010–2100
Future changes in ecosystem services will depend heavily on changes in land cover and land use, which, in turn, are shaped by human activities. Given the challenges of predicting long-term changes in human behaviors and activities, scenarios provide a framework for simulating the long-term consequences of land-cover change on ecosystem function. As input for process-based models of terrestrial and aquatic ecosystem function, we developed scenarios for land cover, population density, and impervious cover for the state of New Hampshire for 2020–2100. Key drivers of change were identified through information gathered from six sources: historical trends, existing plans relating to New Hampshire’s land-cover future, surveys, existing population scenarios, key informant interviews with diverse stakeholders, and input from subject-matter experts. Scenarios were developed in parallel with information gathering, with details added iteratively as new questions emerged. The final scenarios span a continuum from spatially dispersed development with a low value placed on ecosystem services (Backyard Amenities) to concentrated development with a high value placed on ecosystem services (the Community Amenities family). The Community family includes two population scenarios (Large Community and Small Community), to be combined with two scenarios for land cover (Protection of Wildlands and Promotion of Local Food), producing combinations that bring the total number of scenarios to six. Between Backyard Amenities and Community Amenities is a scenario based on linear extrapolations of current trends (Linear Trends). Custom models were used to simulate decadal change in land cover, population density, and impervious cover. We present raster maps and proportion of impervious cover for HUC10 watersheds under each scenario and discuss the trade-offs of our translation and modeling approach within the context of contemporary scenario projects
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