Understanding How Our Planet Works

The first step to understanding how our planet works is to think about our planet as a SYSTEM.   Earth System Science (ESS) is the study of the parts of the Earth and how they work together (their interactions).   ESS is a new science, established in 1987.

Systems Thinking

Once people thought that the Earth was flat.  Now that we know it is round like a ball, and we may laugh about the flat idea!    But people of the Earth are now in the middle of an even greater change in our understanding about our planet.   Most of us don't even know about the new thinking. 

In the past we thought about the Earth as many separate places.... land, ocean, sky,  ice caps ... and separate things, such as people, animals, plants.   Now we are learning something very important.  We are discovering how Earth works as a whole system.  Earth is MORE than round.  Earth is whole:  its features and living organisms are interconnected.  They work together in important ways.   The clouds, oceans, mountains, volcanoes, plants, bacteria, people and animals all have important roles in how our planet works.  

The Six Spheres of the Earth System

The parts of the Earth system are called spheres, and there are SIX SPHERES for you to learn about

The lithosphere  - rocks (or geosphere) The Earth's solid surface is the lithosphere. It includes continental and oceanic crust as well as the various layers of the Earth's interior.

The hydrosphere  - water The hydrosphere is the sphere which includes all of the water on Earth.  71% of the Earth is covered by water and only 29% is solid land.

The cryosphere  - Ice The cryosphere is the part of the Earth's surface where water is in a solid form, usually as snow or ice, and includes glaciers, ice shelves, snow, icebergs, and snow  fields.

The atmosphere  - Air The atmosphere is a gaseous layer that surrounds the Earth.  The atmosphere consists of a mixture of gases composed primarily of nitrogen, oxygen, carbon dioxide, and water vapor.

How are the Spheres Connected?
These spheres are closely connected in many ways. For example, many birds (biosphere) fly  through the air (atmosphere), while water (hydrosphere) often flows through the  soil (lithosphere). In fact, the spheres are so closely connected that a change in  one sphere often results in a change in one or more of the other spheres.
   

Hydrosphere  atmosphere interactions

Warm water from the ocean evaporates until the atmosphere above can hold no more.  The wind (atmosphere) moves the the moisture (water vapor) over a colder part of the ocean.  The atmosphere becomes cold and the water vapor changes to rain.  The rain falls on the ocean and some islands in that area get heavy rain too. 

Other Sphere Interactions & connections

Scroll down to the bottom of this page for examples of connections between the spheres (read the tan boxes).