Interglacialer

Interglacialer are warm phases of Earth’s climate that occur between glacial periods within the Quaternary glacial–interglacial cycles. During an interglacialer, global temperatures rise, continental ice sheets retreat, sea levels rise, and climates become more temperate on average. They are marked by higher atmospheric greenhouse gas concentrations compared with the preceding and following glacial periods and by feedbacks such as reduced ice‑albedo, changes in vegetation, and dust dynamics.

The transition into and persistence of interglacialer are driven primarily by orbital forcing of the climate system, known as Milankovitch cycles. Variations in eccentricity, obliquity, and precession change the distribution and intensity of solar radiation received at high latitudes, promoting summer warming and ice-sheet melt. Greenhouse gases, emitted from natural sources and enhanced by feedbacks within the system, reinforce warming. The result is a relatively warmer, wetter climate that can last thousands to tens of thousands of years, though regional differences are common.

Evidence for interglacialer comes from multiple records, including marine and terrestrial sediments, oxygen isotope ratios in foraminifera, ice cores with greenhouse gas concentrations and temperature proxies, and sea‑level indicators from coastal and coral records. Notable interglacialer include the Eemian interglacial (approximately 130,000 to 115,000 years ago, MIS 5e) and the current Holocene interglacial, which began about 11,700 years ago. While interglacialer are the natural pace of Earth’s climate, recent warming trends are occurring within the Holocene and are influenced by human activities, potentially accelerating or altering future interglacial dynamics.