resources

Materials that can be used to satisfy human needs. 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.

Non-renewable resources include minerals such as coal, copper ores, and diamonds, which exist in strictly-limited quantities. Once consumed they will 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.

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.