The Extreme Environments (ExEn) team addresses environmental, ecological and climatic research questions in extreme ecosystems, ranging from high latitude and high-altitude zones to semi- to hyper-arid regions. Being particularly sensitive to disturbances, these regions are at once at the highest risk of being impacted by future climate change while also being extremely valuable indicators of past environmental change. Our work in ExEn is to assess the impact of global changes (climatic and societal) on the functioning and structure of these extreme environments, on the species that inhabit them and on their potential resilience over long and diverse spatio-temporal scales. Our approach is multidisciplinary and multiscalar, spanning the last 50 millennia and employing the concepts and tools of paleoecology, palaeoclimatology, environmental spatialized data infrastructures, associated numerical analysis tools, modelling and environmental genetics. By combining these perspectives and capabilities, ExEn’s goal is to develop a thorough and comprehensive understanding of the drivers and responses to environmental and ecosystem change in these regions in order to contribute to the development of appropriate management strategies.