UNIT 1: PHYSICAL GEOGRAPHY

Basics: The Key Components of the Environment

The word environment means the surroundings and comes from the french word "environ," meaning around. Thus the environment is all external things that may in any way affect an organism or an object.

The global environment is an all inclusive, interacting and interdependent system. A change to any part of this system could affect some other parts of the system. No event takes place in isolation and all events have effects on the environment. Humans are an integral part of the environment and all actions we take can have effects on other parts of the system.

The global environment has four components

1. the lithosphere - the soils and rocks of the uppermost mantle of the Earth
2. the hydrosphere - all the water in the world - liquid, solid and gaseous
3. the atmosphere - the region of gases extending above the Earth's surface
4. the biosphere.- the part of the planet within which all life is found

The interaction of the four spheres is dynamic and constant.

An ecosystem is a biological community (ie plants and animals) or system formed by the interaction of things in a particular environment with one another and their habitat.