Two of the main current issues in natural sciences are climatic change and human impact on ecosystems. Despite the global character of these processes, it is also vital to determine regional responses with respect to the rate and intensity of changes that influenced our society in the past, that occur today and that will determine the future of natural as well as of economic systems. Reconstruction and monitoring provide means to identify forcing mechanisms, which lead to a better understanding of the climate system and thus improve the quality of predictions. Advances in our knowledge of interactions between climate, ecosystems and human activities will promote a sustainable management of the natural and the human environment in the future.
Indispensable in this respect are continuous and precisely dated natural archives analysed with a multiproxy approach. On the continents such data are for example provided by lacustrine systems with annually laminated (varved) sediments. Such records provide a sufficiently high temporal resolution for a multitude of interdisciplinary analyses that enable a thorough interpretation and reconstruction of climatic influences as well as of various human impacts on natural ecosystems. High-resolution studies are crucial in the context of an appropriate interpretation of processes occurring now and in future on timescales relevant for human societies. Necessary information needs to have a timescale with a resolution of less than 30 years, i.e. less than one human generation, which demands for at least decadal or annual resolution.
During the last decade sequences of annually laminated sediments have frequently been used for the reconstruction of environmental changes, thus becoming a prominent source of information about local, regional and supra-regional changes on the continents. Together with tree rings, speleothems, ice cores and deep-sea sediments these records provide the knowledge that is necessary to draw conclusions about the complex dynamics of the global climate system.
With the exception of Lake Gosciaz absolute chronologies of paleoclimate and paleoenvironmental studies in Poland have been elaborated only with low temporal resolution. With regard to past climate variations there is a deficiency in detailed up-to-date studies taking into consideration short and rapid climatic and environmental changes. Therefore, we envisage a great potential for the area of northern Poland which is spotted with lakes of glacial origin and which is an appropriate region to determine interesting new varved lake records to be investigated in an interdisciplinary manner by the joint Polish-German lake study group NORPOLAR. Such multidisciplinary analyses will provide new and well-dated, continuous and high-resolution, qualitative and quantitative information about general trends and abrupt events of climate and environmental changes.
With NORPOLAR we also refer to one of the major aims of the former European Lake Drilling Programme (ELDP), i.e. to analyze past climate and environmental variability along transects throughout Europe. Lakes to be investigated in the framework of NORPOLAR are located along a W-E transect covering the entire extension of Poland: ca. 700 km from the river Odra (German/Polish international border) in the NW to the Lithuanian/Polish international border in the NE. Such a W-E transect of varve-dated lacustrine sediment records will provide completely new aspects and much more interpretative power thereby considerably increasing the overall value for subsequent climate modelling. Moreover, a spatial extension of this transect to already existing German varved lake records in the W or to emerging records from Estonia and from NW Russia in the E will become a challenging and promising perspective.