Non-renewable resource

A non-renewable resource is a natural resource that cannot be re-made or re-grown. Often fossil fuels, such as coal, petroleum and natural gas are considered non-renewable resources, as they do not naturally re-form at a rate that makes the way we use them sustainable. This is as opposed to natural resources such as timber, which re-grows naturally and can, in theory, be harvested sustainably at a constant rate without depleting the existing resource pool. In this sense, all mined resources, stone, metals, uranium, and various other materials and minerals should be considered non-renewable.

Human resource use

Because human needs are varied and extend from basic physical requirements, such as food and shelter, to spiritual and emotional needs that are hard to define, resources cover a vast range of items. The intellectual resources of a society – its ideas and technologies – determine which aspects of the environment meet that society's needs, and therefore become resources. For example, in the 19th century uranium was used only in the manufacture of coloured glass. Today, with the development of nuclear technology, it is a military and energy resource. Resources are often divided into human resources, such as labour, supplies, and skills, and natural resources, such as climate, fossil fuels, and water. Natural resources are divided into non-renewable resources and renewable resources.

Carbon-based non-renewables

Natural resources such as coal, oil, or natural gas, take millions of years to form naturally and cannot be replaced as fast as they are consumed. Eventually they will be used up. At present, the main energy sources used by humans are non-renewable; renewable resources, such as solar, tidal, wind, and geothermal power, have so far been less exploited. Fossil fuels like coal, oil, and gas generate a considerable amount of energy when they are burnt (the process of combustion). Non-renewable resources have a high carbon content because their origin lies in the photosynthetic activity of plants millions of years ago. The fuels release this carbon back into the atmosphere as carbon dioxide. The rate at which such fuels are being burnt is thus resulting in a rise in the concentration of carbon dioxide in the atmosphere, a cause of the greenhouse effect.

Natural resources are replaced by natural processes given reasonable amount of time. Soil, water, forests, plants, and animals are all renewable resources as long as they are properly conserved. Solar, wind, wave, and geothermal energies are based on renewable resources.

Production materials

Human society uses a huge range of non-renewable resources for producing tools, as well as toys. These include materials such as iron, copper, diamonds, and uranium. These resources exist in strictly-limited quantities. Once consumed they may not be replenished within the time-span of human history. In contrast, water supplies, timber, food crops, and similar resources can, if managed properly, provide a steady yield virtually forever; they are therefore replenishable or renewable resources. Inappropriate use of renewable resources can lead to their destruction, as for example the cutting down of rainforests, with secondary effects, such as the decrease in oxygen and the increase in carbon dioxide and the resulting greenhouse effect. Some renewable resources, such as wind or solar energy, are continuous; supply is largely independent of people's actions.

Resource demand

Demands for resources made by rich nations are causing concern that the present and future demands of industrial societies cannot be sustained for more than a century or two, and that this will be at the expense of the developing world and the global environment. Other authorities believe that new technologies will be developed, enabling resources that are now of little importance to replace those being used up.

Economic models

Hotelling's rule is a 1931 economic model of non-renewable resource management by Harold Hotelling. It shows that efficient exploitation of a nonrenewable and nonaugmentable resource would, under otherwise stable economic conditions, lead to a gradual depletion of the resource. The rule states that this would lead to a net price or "Hotelling rent" for it that rose annually at a rate equal to the rate of interest, reflecting the increasing scarcity of the resource.