This chapter provides a general consideration of the biosphere, the global scale environmental system whose stability lies at the heart of the environmental crisis and which has, as McGraw Hill points out, been extensively altered by human activities. It examines the fundamental biotic processes which influence these cycles, which control ecosystem stability and dynamics, and which are of central concern to environmental management. In the natural state the biosphere can attain a state of equilibrium which is self-sustaining and ecologically efficient. The state of balance of the energy system can be of critical importance to ecological stability and to general environmental equilibrium. The availability and transfer of a wide range of chemical elements in the environment are key factors influencing the stability and continued survival of the biosphere, and the sub-system for these is composed of a series of inter-locking and delicately balanced biogeochemical cycles.