Environmental Change Researc Unit (ECRU), headed by Atte Korhola, forms one of the many research groups in the Faculty of Biological and Environmental Sciences, being also an integral part of the Faculty’s Ecosystems and Environment Research Programme as well as the Helsinki Institute of Sustainability Science (HELSUS). The central research theme in the ECRU is the development and application of empirical, geospatial, computational and modeling tools to detect global environmental changes and to analyse their ecological and societal impacts. We are particularly interested in longer-term climatic changes, critical geo-ecological transitions, sea-ice reconstruction, carbon cycling, ecosystem feedbacks, black carbon, freshwaters, peatland and coastal ecology, biodiversity, lake optical environments, and climate mitigation and adaptation strategies. We mostly work on the arctic environment that is undergoing rapid change across the marine, terrestrial, and atmospheric systems. The research group presently comprises about 15 researchers with a wide spectrum of research interests and skills. We have six Principal Investigators (PI) that lead various sub-projects. The ECRU group is involved in many international and national research programs, including e.g. INQUA PALCOM, PAGES 2k, C-PEAT and AMAP activities.