Global warming is a real problem, but would you believe that we are actually living in an ice age right now?
Most people believe that the ice age ended 20,000 years ago. When in fact, we're in a relatively warm period during the current ice age. Ice ages have occurred for roughly two-hundred of the past six- hundred million years, with each ice age lasting up to ten million years at a stretch. During an ice age, the polar regions of the earth are cold. There's a big temperature difference between the equator and the poles, and at times ice sheets cover huge chunks of the earth's land mass.
Large fluctuations in temperature during an ice age keep the entire world from being covered in ice. During the current ice age, glaciers have advanced and retreated over twenty times. We're living during one of the warmer periods when the glaciers have retreated. At some point, the glaciers will advance again and we'll be covered in ice.