Deglaciation
Deglaciation is the process of ice sheets and glaciers melting as the climate warms, which exposes land and raises sea levels. It can happen on large scales, like the whole planet, or on smaller scales, such as a single glacier.
The most recent major deglaciation began about 21,000 years ago after the Last Glacial Maximum and continued into the early Holocene, ending around 11,500 years ago. A previous large deglaciation occurred from about 22,000 to 11,500 years ago. During these times, summers were warmer, ice melted, and sea levels rose dramatically (roughly 120 meters in total since the peak of the last ice age).
Deglaciation happens when the balance between snowfall and melting shifts toward more melting. This is influenced by changes in Earth's orbit that affect summer warmth, as well as overall climate warming from atmospheric greenhouse gases. Ocean currents and other factors also play a role in how quickly ice retreats.
Today, human activities—especially burning fossil fuels—are driving faster, more widespread deglaciation. Some regions, like West Antarctica, are retreating quickly, and melting ice can release stored carbon and methane, which may further affect climate.
As ice melts, huge amounts of meltwater form lakes, waves erode shorelines, and ice cliffs calve to form icebergs. The landscapes that result record past climates and help scientists understand future changes. Studying these patterns helps us learn how current warming might unfold.
This page was last edited on 2 February 2026, at 21:09 (CET).