THE LAKE SEDIMENTS RESPONSES TO ENVIRONMENTAL AND CLIMATIC CHANGE

The relative significance of the 20th century climatic and environmental changes must be assessed from the long term global scale perspective available from a spectrum of proxy histories,including those from lake sediments. Lake sediments are sensitive to palaeoclimatic and palaeoenvironment change and record quantitative information about the processes and forcing factors responsible for producing both abrupt and long term climate variation. Lake sediments also offer the best potential for a comprehensive interhemispheric comparision with a temporal resolution of decades to centuries .In many cases new geochemical proxies (biogenic carbonate, biogenic silica, organic matter indices) are needed to supplement the established use of stable isotope analyses for palaeotemperature and palaeohydrological modeling to understand the past environment conditions and evaluate predicative models of climate.