Suchergebnisse

The aim of this paper is to present an alternative methodology for discounting far distant future externalities genereted by an investment project: time-declining discount rates. First I present the experimental evidence on individuals' time-inconsistency. Second I consider the theoretical justification for using hyperbolic discounting in a simple uncertainty framework where marginal social utility is discounted hyperbolically if the investing Government believes that social wealth might increase or decrease over future period with a small probability that wealth will deteriorate below its current level.

This book assesses the current available information concerning the major scientific problems related to environmental consequences of a possible nuclear war. The contributors address a broad range of topics, among them the effects of blast, heat, and local radioactive fallout; the likely dispersal patterns and residence times of radioactive debris in the troposphere and stratosphere; the probable long-term effects on both the local and global biosphere and radiological consequences for humans; the effect on the global environment of widespread fires in urban and industrialized regions; and the likely significant decrease of stratospheric ozone with a resulting long-term increase in harmful UV radiation received at the ground. The authors point to problem areas where current information is inadequate or completely lacking and discuss the role of the scientist in developing such information as a contribution to the elimination of the nuclear war threat.

The aim of this thesis is to discuss environmental impacts on river quality. Pollutants from point sources including municipal and industrial sources and from nonpoint sources involving agriculture, urban runoff , mining, silviculture, construction, hydrographic modification and natural sources such as flood can usually cause adverse effects on the environment. These pollutants can be controlled by means of technology and legislation. Wastewater treatment plants can treat wastewater from point sources. Control methods f o r nonpoint source pollution are mainly based on legislation and education. It is more difficult to control the pollution from nonpoint sources than from point sources. The effectiveness of any water quality management plan may be measured in terms of how well the plan accomplishes water quality goals. These goals are usually expressed in the form of wastewater effluent standards or the receiving water quality standards. Water quality models can assist planners in identifying and evaluating possible management programs and in determining which of these best meet the required water quality standards. However, these models should design for both now and future use. The control of technological abuse of the environment, and hence land and river systems, is vital. Aspects of overuse of land f or agriculture, due to population pressures must also be considered.