Das Projekt "CHILL-10000: Klimageschichte ausgehend von Untersuchungsergebnissen oekologisch empfindlicher arktischer und Alpenseenfuer die vergangenen 10000 Jahre, ein Ansatz mit mehreren beobachtbaren Groessen" wird vom Umweltbundesamt gefördert und von Universität Bern, Departement Biologie, Institut für Pflanzenwissenschaften durchgeführt. The general lack of long-term observational climate data results in uncertainties in the understanding of global change and in the ability to predict future changes. Because of the similarities in the distribution of solar radiation and Earth boundary conditions, Holocene palaeoclimates, in particular, can offer insights into the dynamics of climate change as well as providing a means to test the validity of different circulation models (GCMs). The overall goal of this study is to improve knowledge of Holocene climate evolution and variability by producing high-resolution, multi-proxy, and quantitative climate reconstructions across Europe. A particular emphasis will be paid to the spatial and temporal variation of Holocene climates and the relevance of these patterns to the validation and improvement of GCM simulations. The reconstructions will be achieved through the analysis of the extensive and unique proxy data available from the sedimentary deposits of remote high-altitude alpine and sub-arctic European lakes, largerly unaffected by human impact. The approach is highly focused, innovative, methodologically harmonized, and has an explicit multi-proxy nature. The project will improve, expand and apply existing quantitative inference models (transfer functions), based on regional quality-controlled modern organism-climate calibration data-sets, to reconstruct past climates from biological sedimentary sources such as chironomids, cladocerans, diatoms, chrysophyceans, and pollen. The most rigorous numerical techniques available, such as weighted averaging calibration and regression techniques (WA), WA partial least squares regression (WA-PLS), and modern analoque techniques (MAT) will be used in the reconstruction along with sample-spezific errors of prediction. The climate reconstructions derived from the biological data will be complemented by various geochemical and sedimentological analyses, and the overall methodology will be validated by statistical comparison with instrumentally measured climate data. Considerable effort will be paid to sediment sequence quality control, chronology, analytical quality control, and taxonomic consistency and harmonization throughout the work. The final result will be numerical, reliable, statistically-verifiable, precisely-dated, and spatially-weighted reconstructions of European climate within the last 10,000 years.