Earth Science 1.4 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 Earth’s system is powered by energy from two sources One source is the sun, which drives external processes that occur in the atmosphere, hydrosphere, and on earth’s surface Earth’s interior is the second source of 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 also a large part of this system. Our actions and our byproducts produce change in all other parts of the system  A classic example of this is Global Warming. Global Warming is brought about in large part by emissions from man, directly or indirectly.

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 soil Metallic and nonmetallic minerals energy

Resources  Resources are divided into two broad categories Renewable: 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