7,832 research outputs found
Global digital data sets of soil type, soil texture, surface slope and other properties: Documentation of archived data tape
The file structure and coding of four soils data sets derived from the Zobler (1986) world soil file is described. The data were digitized on a one-degree square grid. They are suitable for large-area studies such as climate research with general circulation models, as well as in forestry, agriculture, soils, and hydrology. The first file is a data set of codes for soil unit, land-ice, or water, for all the one-degree square cells on Earth. The second file is a data set of codes for texture, land-ice, or water, for the same soil units. The third file is a data set of codes for slope, land-ice, or water for the same units. The fourth file is the SOILWRLD data set, containing information on soil properties of land cells of both Matthews' and Food and Agriculture Organization (FAO) sources. The fourth file reconciles land-classification differences between the two and has missing data filled in
The Impacts of Climate Change, CO2, and SO2 on Agricultural Supply and Trade: An Integrated Assessment
The analysis of the impacts of alternative future energy paths on the regional supply and trade of agricultural commodities is part of an integrated assessment study undertaken a1 IIASA. For the agricultural study, results from the energy models (i.e., IIR and MESSAGE III) of IIASA's Environmentally Compatible Energy Strategies project and from the regional air pollution model RAINS developed by IIASA's Transboundary Air Pollution project were compiled to define the economic and environmental conditions for a number of simulation experiments with the BLS model.
This paper examines the impacts of climate change and altered concentrations of CO2 and SO2 in the atmosphere, on crop yields and regional food supply. Three different emission abatement scenarios are tested, representing a range of possible economic development and regulatory pathways.
Emission abatement, in terms of agricultural and environmental impacts, is a regional issue much more than a global one. While there is relatively little difference between outcomes at the global level, regional results vary greatly between scenarios
Egyptian Agriculture in the 21st Century
In order to perform a proper, integrated assessment of potential climate change impacts on Egypt it was necessary to accurately identify important and impending issues and problems which are and will be facing the Egyptian agriculture sector into the next century. To this aim, two experts in the fields of Agronomy and Irrigated Agriculture in the Middle East were asked to travel to Egypt in order to assess the current state of Egyptian agriculture and pose possible questions and scenarios that will face Egypt in light of its current agricultural practices and management strategies. The paper examines two possible future scenarios for Egypt, one from a non-climate change perspective and the other from a climate change outlook. These scenarios are derived from the authors perspective of the current state of Egyptian agriculture. One viewpoint is that of the pessimist, where Egypt continues to practice poor agriculture management; the other is that of the optimist, with Egypt adopting sound management practices - adapting its cropping pattern and water use practices. Also addressed are the potential impacts of climate change on crop yields and recommendations for agronomic research to mitigate its potential impact
A 475 years-old founder effect involving IL12RB1: a highly prevalent mutation conferring Mendelian susceptibility to mycobacterial diseases in European descendants
Mutations in IFNGR1, IFNGR2, IL12RB1, IL12B, STAT1 and NEMO result in a common clinical phenotype known as Mendelian Susceptibility to Mycobacterial Diseases (MSMD). Interleukin-12 receptor 01 (IL12R beta 1) deficiency is the most common genetic etiology for MSMD. Known mutations affecting IL12RB1 are recessively inherited and are associated with null response to both IL-12 and IL-23. Mutation IL12RB1 1623_1624delinsTT was originally described in 5 families from European origin (2 from Germany: I from Cyprus, France and Belgium). Interestingly, this same mutation was found in an unexpectedly high prevalence among IL-12R beta 1 deficient patients in Argentina: 5-out-of-6 individuals born to unrelated families carried this particular change. To determine whether mutation 1623_1624delinsTT represents a DNA mutational hotspot or a founder effect, 34 polymorphic markers internal or proximal to IL12RB1 were studied in the Argentinean and the Belgian patients. A common haplotype spanning 1.45-3.51 Mb was shared by all chromosomes carrying mutation 1623_1624delinsTT, and was not detected on 100 control chromosomes. Applying a modified likelihood-based method the age of the most recent common ancestor carrying mutation 1623_1624delinsTT was estimated in 475 years (95% CI, 175-1275), which is the time when the Spaniards initiated the colonization of the Americas. Mutation 1623_1624delinsTT represents the first founder effect described on IL-12R beta 1, the most frequently affected gene in MSMD, and affecting patients with European ancestors. The reason(s) behind the persistency of this mutation across multiple generations, its relative high prevalence, and any potential selective advantage are yet to be established
Bags vs. Strings: Hadrons in Type I and Type II Superconducting Vacua
Two popular models for hadronic structure are bags and strings. Both involve analogies with superconductivity. We claim that the most appropriate analogies are type I superconductors for bags and type II superconductors for strings. The structures of hadrons is somewhat different for the two situations. In principle, and in practice in the real world, it is the similarities which are most important. These include linear confining potentials, linearly rising Regge trajectories and short distance Coulomb potentials. These are all generic properties of bound states in a superconductor and the main distinctions between bags and strings is under what circumstances these limiting behaviors set in
Climate Change Impacts on Agriculture: Challenges, Opportunities, and AgMIP Frameworks for Foresight
Agricultural systems are currently undergoing rapid shifts owing to socioeconomic development, technological change, population growth, economic opportunity, evolving demand for commodities, and the need for sustainability amid global environmental change. It is not sufficient to maintain current harvest levels; rather, there is a need to rapidly increase production in light of a population growing to nearly 10 billion by mid-century and to more than 11 billion by 2100 (FAO, 2016; UN, 2016; Popkin et al., 2012). Current and future agricultural systems are additionally burdened by human-caused climate change, the result of accumulating greenhouse gas and aerosol emissions, ecological destruction, and land use changes that have altered the chemical composition of Earths atmosphere and trapped energy in the Earth system (IPCC, 2013; Porter et al., 2014). This increased energy has already raised average surface temperatures by approximately 1 degree Centigrade (GISTEMP Team, 2017; Hansen et al., 2010), leading early on to the term global warming, but this phenomenon is now more accurately referred to as climate change because it also modifies atmospheric circulation, adjusts regional and seasonal precipitation patterns, and shifts the distribution and characteristics of extreme events (Bindoff et al., 2013; Collins et al., 2013). Food and health systems face increasing risk owing to progressive climate change now manifesting itself as more frequent, severe extreme weather eventsheat waves, droughts, and floods (IPCC, 2013). Often without warning, weather-related shocks can have catastrophic and reverberating impacts on the increasingly exposed global food systemthrough production, processing, distribution, retail, disposal, and waste. Simultaneously, malnutrition and ill health are arising from lack of access to nutritious food, exacerbated in crises such as food price spikes or shortages. For some countries, particularly import-dependent low-income countries, weather shocks and price spikes can lead to social unrest, famine, and migration
Simulating the Socio-Economic and Biogeophysical Driving Forces of Land-Use and Land-Cover Change: The IIASA Land-Use Change Model
In 1995, a new project Modeling Land-Use and Land-Cover Changes in Europe and Northern Asia (LUC) was established at IIASA with the objective of analyzing the spatial characteristics, temporal dynamics, and environmental consequences of land-use and land-cover changes that have occurred in Europe and Northern Asia over the period 1900 to 1990 as a result of a range of socio-economic and biogeophysical driving forces. The analysis will then be used to project plausible future changes in land use and land cover for the period 1990 to 2050 under different assumptions of future demographic, economic, technological, social and political development. The study region, Europe and Northern Asia, has been selected because of its diversity in social, economic and political organization, the rapid changes in recent history, and the significant implications for current and future land-use and land-cover change.
Land-cover change is driven by a multitude of processes. Natural processes, such as vegetation dynamics, involve alterations in cover due to natural changes in climate and soils. However, changes of land cover driven by anthropogenic forcing are currently the most important and most rapid of all changes (Turner et al. 1990). Therefore, any sound effort to project the future state of land cover must consider the determinants of human requirements and activities, e.g., demand for land-based products such as food, fiber and fuel, or use of land for recreation.
In the past, major land-cover conversions have occurred as a consequence of deforestation to convert land for crop and livestock production; removal of wood for fuel and timber; conversion of wetlands to agricultural and other uses; conversion of land for habitation, infrastructure and industry; and conversion of land for mineral extraction (Turner et al. 1993). These human-induced conversions of land cover, particularly during the past two centuries, have resulted in a net release of CO2 to the atmosphere, changes in the characteristics of land surfaces (e.g., albedo and roughness), and decreased biodiversity.
More subtle processes, termed land-cover modifications, affect the character of the land cover without changing its overall classification. For instance, land-cover degradation through erosion, overgrazing, desertification, salinization and acidification, is currently considered a major environmental problem. Although the effects of land-cover modifications may be small at local scales, their aggregate impact may be considerable. For example, use of fertilizers locally has no significance for atmospheric concentrations of greenhouse gases. However, when practiced frequently in many locations, nitrogen fertilizer can make a significant contribution to emissions of nitrous oxide (N2O) globally.
The implementation of a comprehensive land-use change model poses a number of methodological challenges. These include the complexity of the issues involved and the large number of interacting agents and factors; the nonlinear interactions between prices, the supply of and the demand for land-based commodities and resources; the importance of intertemporal aspects; the intricacy of biogeophysical feedbacks; and the essential role of uncertainty in the overall evaluation of strategies.
The interaction mechanisms between biophysical cycles and economic processes have mainly been studied in dynamic simulation models that follow recursive chains of causation, where the past and present events determine what will happen tomorrow. Not surprisingly, many of these studies have led to dramatic predictions, basically because the agents whose behavior is described within the model are themselves assumed to be unable to predict at all. By contrast, in micro-economics it is usually assumed that agents do have the capacity to make informed predictions and to plan so as to avoid the probability of disaster in the future. However, even full information and rationality of individual choice are not always sufficient to avoid disaster. The coordination mechanisms that prevail among economic agents often tend to be of decisive importance.
The aim of this paper is to summarize the LUC project approach and to extend our earlier writings on modeling of land-use and land-cover change dynamics. We discuss the adequacy and applicability of welfare analysis as a conceptual framework for the LUC project at IIASA. We recognize from the outset the complexity of socio-economic and environmental driving forces and the fundamental uncertainties involved in their spatial and temporal interactions (and outcomes). Unlike physical particles, economic agents have the ability to anticipate, and they possess the freedom to change their behavior. This inherent unpredictability, in particular the multiplicity of possible outcomes, calls for a normative approach, and for comparative policy analysis rather than exact prediction. Therefore, we adopt an approach that enables the explicit representation of various policy measures, thus providing a means to search for "better futures", i.e., for trajectories of future development that may alleviate environmental stresses while improving human welfare
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