Earth Science 1.4

Earth System Science

Earth System Science As we study Earth, we see

that it is a dynamic planet with many separate parts that interact.

This way of looking at Earth is called Earth System Science.

It’s goal is to understand Earth as a system made up of numerous interacting parts or subsystems.

What is a system? A system can be any size group of interacting parts that

form a system.

A simple analogy is a cars cooling system. It contains a liquid that is driven from the engine to the radiator and back again. The role of this system is to transfer the heat generated by combustion in the engine, to the radiator, where moving air removes the heat from the system.

Earth as a System

Ear th ’s sys tem is powered by energy f rom two sources

• One source i s the sun , wh ich d r i ves ex te rna l p rocesses tha t occur in the a tmosphere , hydrosphere , and on ear th ’s sur face

• Ear th ’s in te r io r i s the second source o f energy

Earth’s Interior Within the Earth is heat that has been

trapped since the Earth’s formation

There is also heat continuously generated by the decay of radioactive elements.

These sources power the internal processes that produce earthquakes, volcanoes and mountains

Interconnections

The parts of the Earth’s systems are interlinked so that a change in one part can trigger or influence changes in other parts of the system

When a volcano erupts, lava may flow out at the surface and block a nearby valley. This obstruction influences the regions drainage and lakes. Ash from the volcano may block out the sun for a period and influence the amount of solar energy falling in the area affecting plant growth. Animals that eat these plants may die if the plants don’t grow from the lack of light and thus are not present as a food source. All parts connect and a change at one part will ripple through the system.

Humans Affect the System

Humans are a lso a la rge par t o f th is sys tem. Our ac t ions and our byproducts produce change in a l l o ther par ts o f the sys tem

A c lass ic example o f th is is Globa l Warming. Globa l Warming is brought about in la rge par t by emiss ions f rom man, d i rec t ly or ind i rec t ly.

Environment Environment refers to everything that

surrounds or influences an organism

Some aspects of an environment may be biological or social

Other aspects of an environment may be nonliving things such as water, soil, air, rocks,

Conditions such as temperature, humidity, and sunlight affect an environment as well.

All these factors combine to create our physical environment

Resources

Resources are an important part of the Earth Sciences. These include

Water and soilMetallic and nonmetallic

mineralsenergy

Resources

Resources are divided into two broad categoriesRenewable: resources that can be

replenished over relatively short spans of time (such as timber, solar energy, wind power)

Nonrenewable: resources that once used will take a very long period of time to renew (such as oil)

Population Earth’s population is growing rapidly.

By 2010 as many as 7 billion people may inhabit the Earth

As the population grows, so does the demand for the Earth’s resources

Many of our nonrenewable resources are being used up so rapidly that they are becoming in short supply

The search for new pockets of nonrenewable resources, and for alternative renewable approaches, has become an important part of the current paradigm of our society

Environmental Problems As populations grow and earth becomes more crowded

and industrialized, environmental problems continue to become one of our greatest challenges

Threats to the environment include

Air pollution, acid rain, ozone depletion, global warming, disposal of toxic wastes, contamination and depletion of water supplies, destruction of fertile soil areas by poor farming practices, extinction of valuable species of plants and animals, and overfishing of the ocean’s resources are but a few of the issues threatening our environment at present