Many of our archived lessons date back to as early as 2004 when our learning community first formed and unfortunately contain links to content that is no longer updated or exist.  Please note that some of these have been updated, and we continue to update them.  Please check ou

Background on changing albedo values.

In addition to the changes brought about by natural forces, it has recently become apparent that a relative newcomer to planet Earth — the human being — has become a powerful agent of environmental change.

Explore the energy and matter cycles found within the Earth System.