NASA scientist Dr. Waleed Abdalati talks about Earth's own air conditioning system. This whole combination of ice and snow covered regions of the Earth serve to reflect, or reject, a lot of the incoming solar energy. Snow and ice reflect as much as 90 percent of the sunlight striking Earth back into space. Yet most solar energy hits the Earth near the equator. Finally, some of the heat from the equator flows toward Earth's polar regions, where it encounters cold air.
Heat moves from warm to cold. . .
The Arctic regions and Antarctic regions act as heat sinks for the Earth. That's our show. With thanks to the National Science Foundation, I'm Deborah Byrd for Earth and Sky.