For around 12,000 years, the Earth has been in the Holocene epoch, a warmer period following a glacial period. During this epoch, however, there have been around 22 abrupt cold phases, each lasting up to several centuries and leading to the expansion of glaciers.
Source: [Phys.org](https://phys.org/news/2026-07-volcanic-eruptions-pacific-cooled-earth.html)