An ice sheet is a massive, continent-sized body of ice that forms on land and extends over tens of thousands of square miles. Earth currently has two major ice sheets: the Antarctic Ice Sheet and the Greenland Ice Sheet. Together, they hold more than 99 percent of the planet’s freshwater ice. The Antarctic Ice Sheet is the largest, covering approximately 14 million square kilometers (about 5.4 million square miles), an area roughly the size of the contiguous United States and Mexico combined. Its volume is estimated at around 30 million cubic kilometers of ice. In contrast, the Greenland Ice Sheet covers about 1.7 million square kilometers (about 660,000 square miles), roughly 12% of the Antarctic ice sheet’s area, and contains about 2.9 million cubic kilometers of ice. Greenland’s ice sheet has been experiencing rapid and widespread melting during record warm summers, contributing significantly to sea level rise. Antarctica’s ice loss is slower and more localized at present but still substantial. These ice sheets are vital components of Earth’s climate system, acting as reservoirs of freshwater and influencing global sea levels and temperature patterns.
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