Original sentence: By natural environment is meant the "environment of nature", in contrast to some other environment or external milieu that is man-made (thus, not "natural").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.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.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
Edited sentence: In politics and other non-technical contexts, nature or (the) (natural) environment often refers to that part of the natural world that people deem important or valuable, for any reason — economic, aesthetic, philosophical, hedonistic, sentimental, etc.. The word ecology is often used in this same sense.It is the common sense of environment that underlies environmentalism — a broad political, social, and philosophical movement which advocates various actions and policies in the interest of protecting Nature.It is the implicit value system that distinguishes the common sense of environment from its scientific meaning in ecology or biology.The same distinction can be made between the common use of nature (above) and its use in science (a synonym of material world).To a scientist, for example, a pipe dumping raw sewage into a river is the environment for any organisms that manage to thrive in it; whereas in the common sense that same pipe  would be considered damage to the environment.Typical environmentalist goals include reducing pollution and the consumption of non-renewable fuels such as petroleum and coal, develoment of renewable energy sources, conservation and sustainable use of scarce resources such as water, land, and fish, protection of pristine habitats, saving endangered species from extinction, establishment of nature reserves, etc..