Global Environmental Change: The Causes and Consequences of Disruption to Biogeochemical Cycles

Abstract

Since the Earth first came into existence environmental change has involved the redistribution of elements and compounds via biogeochemical cycles. Such cycles link the lithosphere, biosphere and atmosphere within reciprocal relationships. These relationships have been profoundly altered by human activity but remain reciprocal. Examples are given to illustrate the magnitude of anthropogenic perturbations to the global biogeochemical cycles of carbon, nitrogen and sulphur. The major issues concern fossil fuel consumption which influences all three cycles, and agriculture which affects the carbon and nitrogen cycles in particular. Anthropogenic perturbations of these cycles has given rise to some of the most important environmental issues of the 1990s, notably global climatic change, acidification and cultural eutrophication. Policies and protocols to mitigate these problems indirectly represent efforts to manage biogeochemical cycles. In view of a likely 46 per cent increase in human population in the next three decades, biogeochemical perturbations will undoubtedly intensify, the impact of which will require increasingly close management. This will need to take into account the interactions between the cycles.