The environment and climate in which we live varies continuously in time and space. For example, in Norway glaciers have expanded and retreated several times in the last 14000 years, forest composition and extent have changed, lake nutrient-status has varied, and soils have developed. A major challenge in environmental science is to define the magnitude and rates of natural environmental variability so that the extent of recent human impacts on the Earth can be assessed.

As the past environment of the last 14000 years cannot be observed directly, we have to reconstruct what the environment was like indirectly from biological and geological records preserved in lake sediments. Lakes are widespread in Norway and they can respond rapidly to environmental change. Their sediments provide a unique time record of the past environment, including climate, erosion, pollution, and atmospheric inputs.

Different components of the lake-sedimentary record provide 'proxy' time-series or archives of the past environment; sediment composition and clastic input of glacial fluctuations; pollen of regional vegetation; plant macrofossils of regional and local vegetation; chironomids of lake-water temperature; diatoms of lake-water chemistry and ice-cover; oribatid mites of local catchment soils; stable isotopes (H,C,N,O) in sediments of air and lake-water temperature. All of these are related directly or indirectly to past climate. Each 'proxy' inevitably has its strengths and weaknesses, so an essential aspect of this project is to implement quantitative, multi-proxy palaeoenvironmental studies at sites critically located in contrasting climatic areas of Norway, so as to exploit the strengths of each 'proxy' archive, to find consistencies between them, and to identify their weaknesses. Such a multi-proxy approach requires an interdisciplinary, inter-departmental project.

The major areas of research activity are in the Folgefonna peninsula, the Jotunheimen and Dovre mountains, the Lyngen Alps, around the Hammerfest area, and in south-west Norway. The types of records studied to reconstruct the past environment include pollen and spores, diatoms, plant macrofossils, chironomids, mites, sediment properties, sediment magnetism, grain sizes, and sediment composition. Particular emphasis is placed on the history of glaciers in Norway and changes in summer temperature and winter precipitation over the last 11000 years, on rapid climatic events at the last glacial-interglacial transition about 14000-10000 years ago, and on quantitative reconstructions of the past environment. Such reconstructions can be compared with predictions about past climate from climate models that are used to predict future climates. Past environments may thus help us understand the complex relationships in our environment and the interactions between the various factors that influence the environment.

To bring together 9 specialists and their students on environmental and climatic reconstruction from 5 departments within the University of Bergen and to develop an integrated, multi-disciplinary, and coordinated palaeoenvironmental and palaeoclimatic research project involving 5 doctoral students, 2 post-doctoral researchers, and 3 external researchers. The project exploits lake sedimentary archives and uses careful site-selection, innovative methods, and quantitative techniques to reconstruct the natural variability in temperature, precipitation, atmospheric CO2, and wind, over the last 14,000 yr from a range of indirect "proxy" archives preserved in lake sediments (pollen, plant macrofossils, chironomids, mites, diatoms, sediment composition, magnetic properties, stable isotopes).

Project summary

The University of Bergen has a long tradition and expertise in Quaternary geological, botanical, zoological and statistical investigation of palaeoenvironments using lake sediments. There have been nay developments in geological, biological, and statistical techniques over the last 10 years and there is thus the need to train young researchers so that today's expertise is passed on and that new multi-disciplinary approaches can be developed. Palaeoenvironmental research in Bergen has tended to consist of small research groups working more or less independently of each other. The NORPEC project brings together active researchers from different departments into an integrated, multi-disciplinary, and coordinated project that focuses on reconstructing past temperatures, precipitation, atmospheric CO2 concentrations, and wind for the last 14,000 years, thereby providing insights into the natural variability, magnitude, rate, and timing of environmental changes in contrasting areas of Norway. These reconstructions are based on lake-sediment composition and magnetism, assemblages of fossil pollen, plant macroscopic remains, diatoms, chironomids, and mites, and the stable-isotope ratios of C, O, H., and N in sediments. Many of the approaches will produce innovative and quantitative Palaeoenvironmental data. The project design involves careful site selection, multi-proxy analyses of the same cores, quantitative environmental reconstructions using modern calibration functions, and data synthesis in space and time. Five doctoral students, two post-doctoral researchers, several master students, two external researchers, and nine scientists from 5 departments comprise NOPREC. The climatic reconstructions from NORPEC can be used in validation of climate model simulations at the Bjerknes Climate Centre, Bergen. NORPEC has close affiliations with the NFR NORPAST project and the international IGCP PAGES III and LIMPACS and the EC CHILL-10000 projects.