Interdisciplinary scientific study of paleoclimate and paleoenvironment is of the great importance for prediction of future climate and environmental changes. Croatia occupies a key position between eastern and western Mediterranean basins and delimits central European and the Mediterranean regions influenced by different climates. Dinaric karst, covering half of the Croatian territory, offers exquisite potential for such a research, having the wide range of karstic forms already proven as good (paleo)environmental archives, such as terrestrial and submerged speleothems, tufa deposits and lake sediments in karstic lakes and marine algal rims in the coastal area. Within this research various carbonate sediments from different climate zones will be studied: speleothems from 3 locations in littoral Croatia, mountainous Gorski Kotar region and central Croatia, lake sediments from Plitvice Lakes, tufa deposits from Zrmanja River, and marine algal rims from ~8 locations along the eastern Adriatic coast. Research will be based on isotopic methods that include analyses of stable isotope ratios 13C/12C and 18O/16O in carbonate deposits, 2H/1H and 18O/16O in water, and radioactive isotopes 14C and U-Th series for dating. Stable isotopes in carbonates will provide information about past environmental conditions, temperature variations, lake evaporation, bioactivity and productivity, and indicate the origin of carbon and mechanisms of calcite precipitation. Algal rims serve as good and precise sea-level indicators and additionally their morphology, age and stable isotope composition could be directly linked to climate changes. The expected outcome is the estimation of regional response of the environment in Croatia to global changes during the Quaternary, and of differences in response of various carbonates to paleoenvironmental changes and their correlations. The project combines groups from Ruđer Bošković Institute, Faculty of Science (Univ. of Zagreb), and University of Zadar.