Ice Age

climate · glaciers · Earth history · frozen planet

Frozen giants roam. During ice ages, enormous ice sheets called glaciers covered much of the land, and it was cold enough for large animals like woolly mammoths and saber-toothed cats to live in freezing forests and grasslands.

Earth gets chilly. Ice ages happen when Earth's temperature drops enough that ice spreads across continents and even mountain areas. Scientists think changes in Earth's orbit and the sun's energy can trigger these super-cold periods.

Warm and cold cycles. Ice ages aren't constant, they have warmer breaks called interglacials when the ice melts back and temperatures rise, then glacials return when it gets cold again. We're actually living in a warm period right now!

Mountains of ice. Some ice sheets during ice ages were so thick and heavy they covered entire continents and stretched thousands of feet tall, reshaping the landscape and carving out valleys and canyons.

Happening many times. Earth has experienced multiple ice ages over millions of years, the last major one ended about 10,000 years ago, which is when humans started farming and building civilizations.