Quaternary interglacials

Interglacials can be defined nonquantitatively as punctuations or transitions from the end of the terminations to the beginning of a new glacial stage. They are associated with high insolation in the summer of the Northern Hemisphere and a high concentration of atmospheric CO₂. They are warm, relatively stable periods with a high sea level, resulting from the total or significant melting of the Northern Hemisphere Continental Ice Sheets outside Greenland. The Earth is dominated by the development of extensive temperate forests in the mid-latitudes and reduced atmospheric dust. However, all these common characteristics of interglacials do not allow us to establish quantitative thresholds that clearly delimit them, as not all of these parameters occurred at the same time or even in an established order, and the intensity of these parameters was highly variable in each interglacial. Depending on which criterion is considered, 9 or 11 interglacials can be identified in the last 800 ka. In the last 450 ka, interglacials were more intense (higher temperatures and higher sea levels). They lasted between 10 and 30 ka. Important scientific challenges remain to be solved in their understanding, which is of particular importance for predicting possible future scenarios within the Holocene.