Consumption Of Renewable Resources Research Articles

A new heuristic for the multi-mode resource investment problem

This paper considers the problem of minimizing resource investment required to execute the tasks in a project network by a given project due date. A project consists of non-pre-emptive tasks executed in a known and required precedence order. Each task is completed in one of its feasible modes, which may differ not only in task duration but also in consumption of renewable resources. A priority rule heuristic with polynomial computational complexity is presented for this computationally intractable problem. This heuristic simultaneously considers due date constraints and resource usage to select and schedule tasks with one decision rule. This differs from prior multi-mode priority rule scheduling heuristics that apply two consecutive decision rules to schedule tasks. Extensive computational testing indicates promising results.

Ecosystem appropriation by Hong Kong and its implications for sustainable development

The Hong Kong Special Administrative Region is a highly developed modern city where technical and economic advances have made it possible to support 7 million people on 120 km 2 of built-up land, resulting in 58 000 people per km 2, one of the highest population densities in the world. This population depends on a continual supply of materials, energy and information to function, and these resources are mainly supplied from outside Hong Kong's own geographical boundaries. The ecological footprint (EF) of Hong Kong due to its direct and indirect consumption of renewable resources and waste generation is presented. Additionally, the paper traces the spatial patterns of Hong Kong's EF and examines the implications of this ecosystem appropriation. The study finds an EF for Hong Kong of about 6 ha per capita, with the largest appropriation occurring for marine ecosystems. If the impacts of fish farming are included, Hong Kong appropriates a marine area nearly 2000 times its own built-up city area. Current resource consumption and waste generation patterns in Guangdong, China — where much of Hong Kong's terrestrial ecosystem appropriation occurs — are also discussed.

CONSUMPTION OF MATERIALS IN THE UNITED STATES, 1900–1995

▪ Abstract The flows of nonfood and nonfuel materials through the economy have significant impact on our lives and the world around us. Growing populations and economies demand more goods, services, and infrastructure. Since the beginning of the twentieth century, the types of materials consumed in the United States have significantly changed. In 1900, on a per-weight basis, almost half of the materials consumed were from renewable resources, such as wood, fibers, and agricultural products, the rest being derived from nonrenewable resources. By 1995, the consumption of renewable resources had declined dramatically, to only 8% of total consumption. During this century, the quantity of materials consumed has grown, from 161 million metric tons in 1900 to 2.8 billion metric tons by 1995, an equivalent of 10 metric tons per person per year. Of all the materials consumed during this century, more than half were consumed in the last 25 years. This paper examines the general historical shifts in materials consumption and presents an analysis of different measurements of materials use and the significance of their trends.

Towards sustainable development

Sustainable development is a difficult phrase to define, particularly in the context of human ecosystems. Questions have to be asked, such as “Sustainable for whom?” “Sustainable for what purposes?” “Sustainable at the subsistence or at the luxury level?” and “Sustainable under what conditions?” In this paper, development is taken to mean improving the quality of life. (If development were to mean growth , then it could not be sustained over the long term.) Studies of development must, of course, consider economic factors, particularly in the case of societies who suffer from the pollution of poverty. However, cultural and environmental factors are equally important. In fact, development is not sustainable over the long term if it is not ecologically sustainable. The terms maximum sustainable yield of a renewable resource, carrying capacity of a region and assimilative capacity of a watershed or airshed are discussed. Approaches using these resource management tools are recommended when external conditions are not changing very much. The problem today is that unprecedented rates of change are expected in the next century, not only of environmental conditions such as climate but also of socioeconomic conditions such as renewable resource consumption and populations (of both people and of automobiles)! In rapidly changing situations, policies must be adopted that strengthen resilence and ecosystem integrity ; that is, society must increase its ability to adapt. Maintaining the status quo is a long-term prescription for disaster. The problem is of course that little is known about how to design strategies that will increase resilience and ecosystem integrity, and this area of research needs to be strengthened. Some suggestions on appropriate indicators of ecosystem integrity are given in the paper but these need considerable refinement. One of the main problems with long-term environmental policy formulation is the uncertainty to be expected, including the possibility that complete surprises will occur, as the time horizon moves forward. Research programmes will of course reduce the uncertainty but will never eliminate it. There is therefore an urgent need to improve current methods of environmental policy formulation, which avoid foreclosing of options and permit continuous review and adaptation of policies. The Canadian round-table approach is mentioned, as well as the policy-exercise approach developed at IIASA (the International Institute for Applied Systems Analysis).

Differential game theoretic policies for consumption-regulation of renewable resources

Continuous unplanned consumption of renewable resources (e.g., fish) could lead to their extinction. A two-country single-renewable-resource dynamic model is formulated in a differential game-theoretic framework. A competitive market consumer benefit function is used as an objective function to be maximized by each country, subject to the resource population/growth/catch dynamics. The optimal competitive catch strategies are derived, and their economic implications are discussed. It is shown that, in general, the optimal catch strategies are not always competitive. Possibilities for each country to be idle or to apply an optimal (monopolistic) catch strategy are also feasible.