ENVS 101 WW & WX & WY- Objective Four

Unit 1: Introduction To Environmental Science

Objective Four: To describe how the earth operates as a system composed of five major subsystems.

4.0 The Environment as a System

To better understand the natural environment, the impacts that humans are having on the environment, and ways in which humans can alter their behavior and technologies to reduce environmental impact, it is useful to think of nature or the natural environment from a "systems" perspective. A system can be viewed as a group of interacting, interrelated, or interdependent elements forming or regarded as forming a collective entity.

Think of the natural environment as a system which is composed of four parts or components, each with its own unique form, arrangement, characteristics and dynamic. These four subsystems include:

• atmosphere- blanket of gases that surrounds the earth or the gaseous earth;
• lithosphere - the solid earth, composed of rocks and minerals;
• hydrosphere - waters of the earth or liquid earth;
• biosphere - living earth, composed of plants, animals, insects, and all living things except humans.

Remember we said that our language suggests that humans are not part of the natural environment? Humans make up their own subsystem, known as the sociosphere, which includes all people on the earth and all human activity. Kenneth Boulding, a well-known economist described the sociosphere as:

"The social system consists of all human beings on the planet and all their interrelationships, such as kinship, friendship, hostility, status, exchange, money flows, conversations, information, outputs and inputs, and so on. It includes likewise the contents of every person's mind and the physical surroundings, both natural and artificial, to which he relates. This social system clings to the surface of the earth, so that it may appropriately be called the socio-sphere, even though small fragments of it are now going out into space. The sociosphere thus takes its place with the lithosphere, the hydrosphere, the atmosphere, the biosphere, and so on as one of the systems which enwrap this little globe. It has strong inter-relationships with the other spheres with which it is mingled and without which it could not survive. Nevertheless, it has a dynamic and an integrity of its own. It is rather thin in Antarctica, although present there; it is very dense in New York. It is a network rather than a solid sphere or shelf, yet no part of the earth's surface is very far from it. It is a system of enormous complexity, yet not wholly beyond our comprehension".

4.1 Important Environmental System Characteristics

First, the four environmental subsystems - atmosphere, lithosphere, hydrosphere and biosphere - together with the sociosphere, are part of a large, interconnected, inextricably linked system called the earth. Anything that happens in one of these systems affects some other element or phenomena in another system.

Second, these subsystems are anything but static. There are continual interactions and transfers of energy, chemicals, and materials between these five subsystems. Some of these transfers, such as rain, are visible to humans. Other, such as the breakdown of chemicals from formerly living organisms as they decompose are not.

Third, there is continual change throughout the subsystems. In fact, the only constant is change. Some of these changes are natural. Some of these changes are caused by human activities.