interglaciares

Interglacials are warm phases within the longer glacial–interglacial cycles of Earth's climate system. They are characterized by the retreat of continental ice sheets, higher global temperatures, and rising sea levels, as well as shifts in ecosystems toward warmer and wetter conditions.

During interglacials, polar and alpine ice cover diminishes, glaciers thin, and sea level stands at higher values than during glacials. Global precipitation patterns change, and biomes expand into higher latitudes and altitudes. Climate proxies such as marine sediment isotopes, ice core gases, and fossil pollen records document these warmer intervals.

The causes of interglacials are primarily natural and linked to orbital forcing, known as Milankovitch cycles. Variations in eccentricity, obliquity, and precession alter the distribution and intensity of solar energy received by Earth, particularly during summer in the Northern Hemisphere. Feedback processes amplify these changes: higher temperatures release greenhouse gases from oceans and soils, reduced ice and snow cover lowers albedo, and vegetation and ocean circulation respond to and further modify the climate.

Durations and frequencies vary. Most interglacials last on the order of 10,000 to 30,000 years, punctuating the glacial periods. Notable examples include the last interglacial, the Eemian (about 125,000 to 114,000 years ago), and the current interglacial, the Holocene, which began around 11,700 years ago and continues today. Studying interglacials helps scientists understand natural climate variability and the potential responses of the climate system to increased greenhouse gas concentrations.