Step 1 : Introduction to the question "What percentage of Earth's surface is permanently covered with ice and snow?"
...Snow cover can change dramatically with seasonal snow falls. During the cold of winter, up to 33 percent of the Earth's land mass may have snow cover. This is temporary, however. Permanent snow and ice cover is present on only 12 percent of the Earth's surface year round, with most of this found in the polar regions. The Earth's climate is a product of sunlight absorption by snow and ice, along with the land and sea. Snow and ice have a high ratio of reflected to transmitted sunlight (albedo.) Source: Education.SeattlePI.com
