History of the terrestrial environment in the Quaternary of Denmark

Changes in the environment backward in time can be reconstructed by measurement of geophysical, geochemical or palaeolontological paramenters in sediment columns. Changes in the elemental spheres of the environment are forced by changes in insolation and by mutual interactions. The glacial-interglacial cycles are provoked by minima and maxima in insolation and reflect changes in biosphere and geosphere. The last summer insolation maximum in the Northern Hemisphere coincides with the beginning of the Holocene. Decreasing insolation affected the altitudes of the glacial equilibrium line and the tree line in Norway, and air humidity in Denmark. The reestablishment of deciduous woodland coincided with the temperature maximum. The introduction of agriculture caused increasing deforestation, especially in densely populated areas, where the agricultural exploitation expanded with increasing precipitation. The environment was increasingly affected by man up towards present time. The natural climate development may be changed by air pollution. Air pollution due to industrialisation is registered by increased deposition of airborne particles on bogs and in lakes, and pollution of aquatic environments by increased adduction of nutritional elements to freshwater lakes.