By natural environment is meant the "environment of nature", in contrast to some other environment or external milieu that is man-made (and thus, not "natural"). The word "ecology" is often used in this same sense to mean the natural world that surrounds us and is largely outside of our obvious manipulations, although certainly not beyond mankind's ability to impact. Within the biosphere, there exists no straight-forward way to separate what belongs to the natural environment and what does not, partly for the reason that humans are part of nearly all natural environments and have been for hundreds of thousands of years. Thus, most people would admit that some level of human exploitation is allowable without the status of any particular landscape ceasing to be a natural one. At some level, urban dwellers would consider a large park to be a natural environment (despite nearly everything present having been arranged or planted) for its contrast in presentation of nature to the standard streets and buildings of the city. Thus, "natural environment" is a term whose exact meaning is often dependent upon context.

It is the common sense of a natural environment that underlies environmentalism—a broad political, social, and philosophical movement which advocates various actions and policies in the interest of protecting Nature. Typical environmentalist goals include reducing pollution and the consumption of non-renewable fuels such as petroleum and coal, development of renewable energy sources, conservation and sustainable use of scarce resources such as water, protection of pristine ecosystems, saving endangered species from extinction, establishment of nature reserves, etc.

See also

• Ecology (the science)
• The Gaia theory
• List of environment topics
• Natural capital
• Natural history
• Wildlife