ABSTRACT
Editors’ note This chapter provides a useful synopsis of our understanding and recognition of the history of the Earth’s climatic and landscape change over the last million years, though concentrating on the last few hundred thousand years. Some of Neil Roberts’s findings should be recalled as later chapters are read. Changes in solar radiation due to the earth’s orbital variations correspond quite well with successive ice advances, but they may have been enhanced by the changing atmospheric concentration of greenhouse gases, which also correlates well with temperature change in the last 150,000 years. This can be borne in mind when reading Max Wallis’s chapter (Chapter 5) on costing global warming. Roberts’s conclusion that changes in precipitation at low latitudes are as important as changes in temperature at high latitude and can occur quite rapidly, and that landscapes are quite often out of equilibrium with current conditions, is of significance to a better understanding of William Beinart’s chapter (Chapter 8) on the perception of environmental change in Southern Africa.
