Interglacial periods are warm phases in Earth's climate that occur between ice ages. During these times, glaciers retreat, and temperatures rise, leading to the expansion of forests and other ecosystems. These periods can last thousands of years and significantly impact sea levels and biodiversity. The most recent interglacial period is known as the Holocene, which began around 11,700 years ago after the last major ice age. During the Holocene, human civilizations developed, and the climate has remained relatively stable, allowing for agriculture and population growth across the globe.