Ancient DNA preserved in soils, ice, and sedimentary archives provides a powerful molecular window into past ecosystems, biodiversity, and environmental change. This session brings together advances in ancient environmental genomics, sedimentary ancient DNA (sedaDNA), and paleogenomics to explore how genetic traces of prokaryotes and eukaryotes can be used to reconstruct evolutionary processes, ecosystem dynamics, and Quaternary climate trajectories. While the field is rapidly expanding, it remains limited by challenges associated with DNA degradation, extraction, sequencing, and authentication. Addressing these constraints requires standardized protocols, geochemical fingerprinting, and methodological innovation across disciplines including geochemistry, microbiology, molecular biology, biochemistry, microbial ecology, genomics, and paleoclimatology. We invite contributions showcasing interdisciplinary case studies, technical developments, and integrative frameworks that leverage sedimentary molecular archives to refine reconstructions of past environmental change and inform conservation strategies for the future.