Assessing the Impact of Climatic Change in Cold Regions

In September 1983 IIASA, together with the Austrian Government, the World Resources Institute and UNESCO, supported an International Study Conference on the Sensitivity of Ecosystems and Society to Climatic Change, which was cosponsored by the World Meteorological Organization, UNEP, and the International Council of Scientific Unions. The purpose of this meeting, which was attended by scientists from 17 countries, was to evaluate the impact of climatic fluctuations on the sensitive margins of agriculture and of natural terrestrial ecosystems. The emphasis was on climatic change that might result from increases in the amount of carbon dioxide in the atmosphere, but consideration was also given to past climatic fluctuations, both short- and long-term. This report is a summary of deliberations by participants in the workshop, of the observations that emerged, and of the recommendations made

The Effect of Climatic Variations on Agricultural Risk

The thesis of this paper is that impacts from climatic change can be evaluated effectively as changes in the frequency of short-term, anomalous climatic events. These can then be expressed as changes in the level of risk of impact from climatic extremes. To evaluate this approach, the risk of crop failure resulting from low levels of accumulated temperature is assessed for oats farming in southern Scotland. Annual accumulated temperatures are calculated for the 323-year long temperature record compiled by Manley for Central England. These are bridged across to southern Scotland and, by calculating mean levels of risk for different elevations, an average "risk surface" is constructed. 1-in-10 and 1-in-50 frequencies of crop failure are assumed to delineate a high-risk zone, which is mapped for the 323-year period by constructing isopleths of these risk levels. By re-drawing the risk isopleths for warm and cool 50-year periods, the geographical shift of the high-risk zone is delineated. The conclusion is that relatively recent and apparently minor climatic variations in the United Kingdom have in fact induced substantial spatial changes in levels of agricultural risk. An advantage of expressing climatic change as a change in agricultural risk, is that support programs for agriculture can be re-tuned to accommodate acceptable frequencies of impact by adjusting support levels to match new risk levels

Assessing Impacts of Climatic Change in Marginal Areas: The Search for an Appropriate Methodology

With the support of the UN Environmental Programme a major 2-year project is currently being initiated to investigate the impacts of short-term climatic variations and the likely long-term effects of CO2-induced climatic changes on agricultural output at the sensitive margins of food grains and livestock production. This paper sets the stage for the above-mentioned project. It reviews the notion of climate-related marginality, and proposes to measure the impact of climatic fluctuations on marginal areas by a temporal change in the level of risk of harvest failure and spatial shifts of crop pay-off boundaries. The practical usefulness of these measures is illustrated by several case examples from the US, Canada, and Northern Europe. Finally, the paper outlines the crop/climate simulation model, successfully applied for analysis of the effects of possible climatic changes on cereal yields in Northern England. Over the next two years it will be the aim of the IIASA project to further develop this methodology and to evaluate the impact on food production of possible changes in climate

A modeling framework for assessing adaptation options of Finnish agriculture to climate variability and change

To enable ex ante assessment of alternative adaptation strategies for Finnish agriculture at multiple scales, MTT Agrifood Research Finland and partner institutes recently launched a project Integrated Modeling of Agrifood Systems (IMAGES).The project aims at developing and evaluating different component (economic and biophysical) models and link them in an integrated modeling framework

Climate Impact Analysis in Cold Regions

Among the many factors influencing agricultural and forest productivity worldwide, the effects of weather and climate are of considerable importance. Anomalous fluctuations of climate, particularly thermal conditions, can have a marked effect in high latitude regions where activities are already constrained by low temperatures and a short growing season. Moreover, a consideration of possible future climatic changes (e.g. those that may result from increased concentrations of atmospheric carbon dioxide) adds a further dimension to the problem of assessing the regional sensitivity of crop production to climate. In many regions, the impacts of a climatic event extend well beyond the direct, physical response of crops. For instance, the resulting changes in crop production may affect farm incomes, regional food-based industries, employment and prices, with the ripple-effects filtering through to other sectors of an economy and society. This paper outlines a methodology for assessing the sensitivity of crop productivity to climate and shows how this may be elaborated to include a consideration of the economic and social implications of crop productivity changes. The approach uses a hierarchy of models, each one representing a stage in the cascade of responses induced by an anomalous climatic event. In particular, three sets of models are identified - of climatic changes, of climate impacts on potential and actual yield, and of the down-stream economic and social effects of these. By considering a range of credible future climatic scenarios, it is possible to produce estimates of impact and to examine a range of adjustments that might be of interest to the agricultural planner or decision-maker. The methodology is being tested in ten countries as part of a two year IIASA/UNEP research project

Hall effect in the marginal Fermi liquid regime of high-Tc superconductors

The detailed derivation of a theory for transport in quasi-two-dimensional metals, with small-angle elastic scattering and angle-independent inelastic scattering is presented. The transport equation is solved for a model Fermi surface representing a typical cuprate superconductor. Using the small-angle elastic and the inelastic scattering rates deduced from angle-resolved photoemission experiments, good quantitative agreement with the observed anomalous temperature dependence of the Hall angle in optimally doped cuprates is obtained, while the resistivity remains linear in temperature. The theory is also extended to the frequency-dependent complex Hall angle

Hawking Radiation as Tunneling for Extremal and Rotating Black Holes

The issue concerning semi-classical methods recently developed in deriving the conditions for Hawking radiation as tunneling, is revisited and applied also to rotating black hole solutions as well as to the extremal cases. It is noticed how the tunneling method fixes the temperature of extremal black hole to be zero, unlike the Euclidean regularity method that allows an arbitrary compactification period. A comparison with other approaches is presented.Comment: 17 pages, Latex document, typos corrected, four more references, improved discussion in section

Tracking the tempo of a continental margin arc: insights from a forearc succession in West Antarctica

The Fossil Bluff Group of eastern Alexander Island records the exceptional preservation of more than 8 km of Mesozoic sedimentary rocks deposited into an accretionary forearc basin that developed unconformably above a late Paleozoic accretionary complex, and in proximity to a continental margin arc during a prolonged phase of enhanced magmatism. Through the Mesozoic, the Fossil Bluff Group evolved from a trench-slope environment to a forearc basin sourced from the continental margin arc. During this period, the Antarctic Peninsula’s convergent margin was characterized by episodes of magmatic flare-ups that developed during tectonic compression, crustal thickening, extension, and uplift. U-Pb and Lu-Hf detrital zircon data are used to determine the provenance of the forearc succession and as a monitor of arc magmatic tempos during the late Mesozoic. The magmatic record in the adjacent arc is poorly preserved or partially absent, but the sedimentary record of the forearc basin preserves a largely uninterrupted record of arc magmatism that can be studied with detrital zircon geochronology and geochemistry. The basal succession of the Fossil Bluff Group is sourced from the adjacent accretionary complex, but thereafter it is strongly controlled by the proximal arc in western Palmer Land and is characterized by a mixed arc/recycled signature during episodes of renewed sedimentation. However, the main phases of deposition during the Early Jurassic (ca. 180 Ma), Early Cretaceous (141–131 Ma), and mid-Cretaceous (125–102 Ma) are dominated by arc-only sources. The Lu-Hf isotopic record supports a transition from convergence to extension and a return to convergence during the Mesozoic, which is consistent with accretionary orogens from elsewhere along the West Gondwanan margin. The provenance record during the depositional history of the basin points overwhelmingly to an autochthonous origin; as such, models for parts of the western province of the Antarctic Peninsula being allochthonous are unsupported

The structure of blocks with a Klein four defect group

We prove Erdmann’s conjecture [16] stating that every block with a Klein four defect group has a simple module with trivial source, and deduce from this that Puig’s finiteness conjecture holds for source algebras of blocks with a Klein four defect group. The proof uses the classification of finite simple groups