The oceans, atmosphere, and land all play critical roles
in sustaining life on Earth. The characteristics of ocean currents, wind patterns, and
topography can make one area a desert and another a rain forest.
greatly affect Earth's plant life or vegetation. The shades of
green and yellow show how leaf bearing plants "green up" and decline through the
seasons of a year. The vast deserts of North Africa, the Arabian Peninsula, and central
Asia are easily recongnized because of the lack of vegetation.