A basic textbook introducing the principles underlying structure and function in the biosphere and outlining its historical development through geological time. This book has been designed particularly for students with little formal biological training who are engaged in degree level work n geography and other environmentally-centred subjects. High priority has been given to making the various topics discussed accessible and comprehensible to the non-specialist. The reader is introduced to investigational techniques and given an insight into the most recent ideas. Major environmental problems and human impacts on the biosphere are considered in the context of relevant natural processes.