The changing environments of the past 50,000 years in the Australian region provide keys to understanding modern landscape, ecological and human processes. In reviewing these changes techniques commonly used to provide a reconstruction of the past ecology, climate, and surface processes are introduced. The source of sedimentary archives and proxy records requires landscape assessments and skills in a range of geomorphological and chronological methods. Biological techniques to be studied include analyses of pollen, charcoal, wood, seeds, insects, stable isotopes and biogenic silica. The contribution of these techniques to particular prehistoric problems such as detecting the role of human activity in environmental change is also covered.