Extrapolation Of Historical Trends Research Articles

Combination of Backward and Forward Approaches for Future Prediction by Business Intelligence Tools

Business intelligence tools now play an important role in data collection, processing and analyses of organizations. Managers may use outputs of such tools and make improved decisions. To provide an even better situation for managers, business intelligence tools may be used to predict future and display present and past statuses of the organization. Available business intelligence tools predict future based on historical data, i.e., they are said to enjoy backward approaches. In this study, it was tried to change extrapolation of historical trends according to our expectations of future events so that forward approaches could be employed for prediction purposes.

Short-term prognosis of development of barrier-type coasts (Southern Baltic Sea)

The indiccatory forecasting of coastal zone changes is extremely important in view of proper management of this zone. Intense pressure on the development of coastal areas makes the importance of forecasting changes increased. The study presents prognostic variants (forecasts) for various development trends of the micro-tidal, wave dominated sea coast (Polish part of the Southern Baltic Sea) in the next 15 years. The main idea was to compare changes and to analyse them using various geoprocessing and statistical techniques based on the spatial analyses of different cartographical materials and extrapolation of historical trends. The basic premise for achieving this objective was to implement the problem-solving principle that makes the fewest possible assumptions. The performed works aimed at mapping the course of the shoreline at various time periods revealed significant changes in its location. All the presented forecasts (“shoreline extrapolation models” and “averaged shoreline changes model”) are characterized by certain volatility and specific features. In authors' opinion the “averaged shoreline changes model” is the most suitable for bulk visualization of shoreline changes. It averages short-term variables that can affect transparency of the image. It also allows avoiding the accumulation of errors that can have an imprint on shoreline variations. The largest forecasted shoreline changes may exceed 100 m. However, this value is highly controversial. The forecast based on the course of the dune base shows more stable situation and the expected changes have a marginal extent. The biggest differences between the two prognostic lines generated basing on the rate from periods 2010–2016 and 2001–2016 can reach up to 40 m. The “averaged shoreline changes model” (which in authors' opinion is the most suitable for bulk visualization) indicates the shoreline changes will affect the beach-wide part of the coast (up to almost 70 m). The biggest dislocation of shoreline will occur in the area of the most intense erosion (vicinity of 144–145 km and 155.5 km) and can affect the dune base.

A Flexible Approach to Forecasting Coastline Change on Wave-Dominated Beaches

ABSTRACT Kinsela, M.A., Morris, B.D., Daley, M.J.A. and Hanslow, D.J., 2016. A Flexible Approach to Forecasting Coastline Change on Wave-Dominated Beaches. In: Vila-Concejo, A.; Bruce, E.; Kennedy, D.M., and McCarroll, R.J. (eds.), Proceedings of the 14th International Coastal Symposium (Sydney, Australia). Journal of Coastal Research, Special Issue, No. 75, pp. 952–956. Coconut Creek (Florida), ISSN 0749-0208. Standard methods of predicting coastline change typically rely on the analysis and extrapolation of historical trends, or simple geometric rules that consider the response of idealised coastal morphology to environmental change – e.g. the Bruun rule of coastline retreat due to sea level rise. In practice, predictions based on such methods are often challenged, due to the limited capacity to characterise natural geomorphic complexity, and consequently, the inability to satisfy restrictive assumptions. While statistical simulation methods offer a means to manage uncertainty in environmental forcing, ...

How China’s Options Will Determine Global Warming

Carbon dioxide emissions, global average temperature, atmospheric CO2 concentrations, and surface ocean mixed layer acidity are extrapolated using analyses calibrated against extensive time series data for nine global regions. Extrapolation of historical trends without policy-driven limitations has China responsible for about half of global CO2 emissions by the middle of the twenty-first century. Results are presented for three possible actions taken by China to limit global average temperature increase to levels it considers to be to its advantage: (1) Help develop low-carbon energy technology broadly competitive with unbridled carbon emissions from burning fossil fuels; (2) Entice other countries to join in limiting use of what would otherwise be economically competitive fossil fuels; (3) Apply geo-engineering techniques such as stratospheric sulfur injection to limit global average temperature increase, without a major global reduction in carbon emissions. Taking into account China’s expected influence and approach to limiting the impact of anthropogenic climate change allows for a narrower range of possible outcomes than for a set of scenarios that are not constrained by analysis of likely policy-driven limitations. While China could hold back on implementing geoengineering given a remarkable amount of international cooperation on limiting fossil carbon burning, an outcome where geoengineering is used to delay the perceived need to limit the atmospheric CO2 concentration may be difficult to avoid.

Projected climate change in Australian marine and freshwater environments

Changes in the physical environment of aquatic systems consistent with climate change have been reported across Australia, with impacts on many marine and freshwater species. The future state of aquatic environments can be estimated by extrapolation of historical trends. However, because the climate is a complex non-linear system, a more process-based approach is probably required, in particular the use of dynamical projections using climate models. Because global climate models operate on spatial scales that typically are too coarse for aquatic biologists, statistical or dynamical downscaling of model output is proposed. Challenges in using climate projections exist; however, projections for some marine and freshwater systems are possible. Higher oceanic temperatures are projected around Australia, particularly for south-eastern Australia. The East Australia Current is projected to transport greater volumes of water southward, whereas the Leeuwin Current on the western coast may weaken. On land, projections suggest that air temperatures will rise and rainfall will decline across much of Australia in coming decades. Together, these changes will result in reduced runoff and hence reduced stream flow and lake storage. Present climate models are particularly limited with regard to coastal and freshwater systems, making the models challenging to use for biological-impact and adaptation studies.

The Sustainability of Health Spending Growth

We evaluate the long-run sustainability of health spending growth. Under the criterion that non-health consumption does not fall, 1 percent excess cost growth appears to be an upper bound for the economy as a whole when the projection horizon extends over the century, although some groups would experience declines in non-health consumption. More generally, the increase in health spending as a share of income may lead to a signifi cant expansion of public sector fi nancing, as has been the case historically. Extrapolation of historical trends also suggests that higher health spending will lead to insurance contracts with lower out-of-pocket payment shares, putting further upward pressure on health care expenditures.

The Sustainability of Health Spending Growth

We evaluate the long-run sustainability of health spending growth. Under the criterion that non-health consumption does not fall, 1 percent excess cost growth appears to be an upper bound for the economy as a whole when the projection horizon extends over the century, although some groups would experience declines in non-health consumption. More generally, the increase in health spending as a share of income may lead to a signifi cant expansion of public sector fi nancing, as has been the case historically. Extrapolation of historical trends also suggests that higher health spending will lead to insurance contracts with lower out-of-pocket payment shares, putting further upward pressure on health care expenditures.

A Correction to the Perspective Titled "Misdirection on the Road to Shangri-La" by Olshansky et al.

Will life expectancy in the United States rise or fall in this century? The implications of either scenario are far reaching. We contend that the rise of childhood obesity in the United States in the past three decades has been so dramatic that it will soon lead to higher than expected death rates at middle ages and a possible decline in life expectancy by midcentury. The most detrimental health and longevity effects will not be seen for decades--a phenomenon that cannot be detected by current methods used to forecast life expectancy or estimate the number of deaths currently attributable to obesity. This scenario contrasts sharply with the views of mathematical demographers who generate forecasts by relying on the assumption that the U.S. pattern of longevity will follow that of other longer lived nations and on the extrapolation of historical trends in life expectancy into the future.

Misdirection on the Road to Shangri-La

Will life expectancy in the United States rise or fall in this century? The implications of either scenario are far reaching. We contend that the rise of childhood obesity in the United States in the past three decades has been so dramatic that it will soon lead to higher than expected death rates at middle ages and a possible decline in life expectancy by midcentury. The most detrimental health and longevity effects will not be seen for decades--a phenomenon that cannot be detected by current methods used to forecast life expectancy or estimate the number of deaths currently attributable to obesity. This scenario contrasts sharply with the views of mathematical demographers who generate forecasts by relying on the assumption that the U.S. pattern of longevity will follow that of other longer lived nations and on the extrapolation of historical trends in life expectancy into the future.

The Sustainability of Health Spending Growth

We evaluate the long-run sustainability of health spending growth. Under the criterion that non-health consumption does not fall, one percent excess cost growth appears to be an upper bound for the economy as a whole when the projection horizon extends over the century, although some groups would experience declines in non-health consumption. More generally, the increase in health spending as a share of income may lead to a significant expansion of public sector financing, as has been the case historically. Extrapolation of historical trends also suggests that higher health spending will lead to insurance contracts with lower out-of-pocket payment shares, putting further upward pressure on health care expenditures.

Principal land use changes anticipated in Europe

Major changes in land use may be anticipated in Europe in the decades to come as a result of technological, socio-economic and political developments as well as global environmental change. The type and effects of these changes will strongly depend on policy decisions which are governed, amongst others, by: (i) an increasing agricultural productivity; (ii) an increasing realization of the need to conserve bio-diversity and environmental quality for current and future generations; (iii) pressure from an increasingly urban population to emphasize non-agricultural forms of land use in terms of nature and landscape conservation; (iv) increasing market-driven demand for high quality produce made with environmentally friendly forms of management; and (v) increasing food demand on the world market as the world population doubles and purchasing powers increases, particularly in Asia. These developments occur now both in Eastern and Western Europe, even though historical developments during the last 50 years have been strikingly different in these two regions. Collectivization in Eastern Europe after World War II was associated with higher yields but also with unfavourable changes in land use and cropping patterns causing acidification, soil erosion, salinization and chemical pollution. The change to democracy in the late 1980s implied a change from an essentially quantity- to a more quality-oriented type of agriculture, like in Western Europe where an industrialized agriculture had also caused environmental problems. Emphasis is now being placed on rational land use, which includes optimization of farm size and the development and implementation of economically viable crop production techniques which result in high quality produce as well as limited adverse environmental side effects. However, these ideals are far from being realized. According to some studies, the technical possibilities of modern agriculture can theoretically in future provide an adequate volume of produce from only 30 to 50% of the current agricultural area in western Europe. This implies potential for other forms of land use in the remaining land area. However, other studies emphasizing low external input agriculture or extrapolation of historical trends, indicate that the current land area may be needed to produce adequate food, certainly when considering the future world market demand. This conclusion is also supported by the fact that theoretical production levels are often much higher than real levels, because of various agronomic and socio-economic factors. A major challenge for the decades ahead is to avoid uncontrolled developments of land use with possibly adverse socio-economic and environmental effects; the latter include the time-delayed release of harmful chemicals, currently held in some soils, into the environment and the enhanced emission of radiatively active trace gases from soils to atmosphere. Controlled developments yielding sustainable forms of agricultural land use in some areas and nature development in others, is to be preferred and should ideally be based on eco-regional approaches. The authors advocate initiation of comprehensive, exploratory studies for Europe in which sustainable production of major land units is defined as a function of different types of land management and in which Europe is seen as part of the world economy. Six exploratory studies are reviewed in this paper; however, none of these scenario studies has the necessary comprehensive character and none is based on adequate land data.

Raising the Productivity of Energy Utilization

A detailed economic analysis is made of the physical options for energy conservation. The study shows that savings of 30 to 40 percent of the expected future total energy demand in the US would be far less expensive than supplying the increased amounts of fuel and electricity dictated by the extrapolation of historical trends. Information is included on the interrelationships of energy use, energy sources, energy conservation economics, standard-of-living, employment, political action, and the quality of the environment. 156 references. (LCL)

Forecasting water use in a constrained environment

Traditional water use forecasting methodologies have been based primarily upon extrapolation of historical trends into the future, using either single or multidimensional regression analysis. However mathematically eloquent, these techniques are in many cases today totally inadequate for providing planners and decision makers with meaningful guidance on expected future water use.The primary reason for this lies with the pure and simple fact that in more and more cases within the United States, the ‘limits to growth’ concepts are beginning to be felt in both the heavy water using portions of the economy and the portions not related to water. The direct and indirect effects of this on future water use are impossible to predict with any confidence by using forecasting techniques based on the analysis and extrapolation of historical trends. To correct this, the following basic concepts should guide the development and utilization of future water use forecasting procedures.