Khan Academy
Khan Academy: Introduction to Conservation Science
Consider the future of the biosphere in this video that discusses the field of conservation science. [6:44]
Bozeman Science
Bozeman Science: Earth Materials & Systems
In this video, Paul Andersen describes the four major spheres on planet Earth. The geosphere makes up the mass of the planet and includes the major landforms. The hydrosphere is all of the water and the atmosphere is all of the gases....