FROST · Frozen in time – Unravelling Younger Dryas climate variability, environmental dynamics and their impact on human recolonization in Western Europe

The Late Glacial period, at the end of the Pleistocene, is marked by dynamic climatic and environmental changes. During this time, hunter-gatherers gradually recolonized Western Europe after a retreat of several millennia, representing a pivotal phase in the region’s population history. However, during the final climatic cooling of the Late Glacial, known as the Younger Dryas (ca. 12,850 to 11,650 cal BP; YD), the number of archaeological sites drastically reduced, raising questions about population decline, migration, and adaptation to severe environmental stress. Despite its significance, the human responses to these climatic shifts remain poorly understood.The FROST project aims to bridge this gap by investigating the impact of climate fluctuations within the YD on human populations, mobility, subsistence strategies, and the ecosystems they depended on. The project uses a multi-proxy approach, integrating palaeoclimate, palaeoecological, and archaeological data from 30 key sites across Western Europe. This includes high-resolution analysis of speleothems (isotopes, trace elements), pollen, sedaDNA, sediments (granulometry, MS, LOI, micromorphology), and reindeer remains (isotopes) from archaeological sites. These data will be anchored with high-resolution dating using 14C, OSL, U/Th and tephrochronology. FROST tackles four core challenges: (1) reconstructing regional climate variability within the YD, (2) assessing ecosystem responses to these climate shifts, (3) tracking reindeer herd movements, and (4) refining the timing and spatial dynamics of human occupation patterns. By integrating these datasets into demographic and spatiotemporal models, FROST will explore how prehistoric populations adapted to environmental changes. This will not only significantly advance our understanding of human recolonization during a crucial phase in Western Europe, but also provide insights relevant to contemporary climate challenges.