ABSTRACT
This chapter is about change in the physical environment which controls ecosystems. Humans find change both exciting and threatening. For ecosystems, response to change is constant. The evolution of the planet, its ecosystems and life-support systems is a record of continual change in which there are winners and losers. Biological winners are organisms which evolve so successfully as to dominate ecosystems for long periods of time. Winners include flowering plants, particularly trees and grasses, and in the past, dinosaurs. Losers become extinct. So, as dinosaurs have shown, winners can become losers. This book has shown that the biotic and abiotic environment changes over time, and at different time scales, as well as in space at any point in time. In this section we examine global-scale environmental changes, which have had, and will continue to have, the ultimate influence on the biosphere as a whole. The principal control of environmental change as a whole is climate. In this chapter we consider how the biosphere may be changed as a result of global climatic change. This may be the most significant and threatening impact upon the biosphere which has ever confronted humankind.
