An environment is made up of the circumstances, objects, or conditions by which an object is surrounded; or, in which an action occurs. In some sciences, the term "milieu" is used synonymously with "environment"; so as to avoid confusion with the definitions of environment which are used in ecology and sociology.

In politics, the term the environment generally refers to the natural world as perceived by humans, with particular reference to damage done by mankind, or impact of this damage on human beings. Efforts to reduce this impact--such as reducing pollution, advocating lower consumption of petroleum, and switching to renewable energy--are usually collectively called environmentalism.

This is in contrast to the term "ecology" which refers to the operations and cycles of life in the natural world, without reference to mankind except as observer. When used politically it refers more to preservation of natural capital for sustainable use, and the right of other species to exist for their own sake and not suffer extinction, as opposed to being part of a human environment.

See also

ecology movement, environmental movement, conservation movement, environmental engineering

list of environment topics

The term environment is also used in a technical meaning in functional programming, the lambda calculus and programming language design.

For the technical meaning in thermodynamics, see Surroundings (thermodynamics).