Geography's most radical departure from conventional disciplinary specializations can be seen in its fundamental concern for how humans use and modify the biological and physical environment (the biophysical environment) that sustains life, or environmental-societal dynamics. There are two other important domains of synthesis within geography as well: work examining interrelationships among different biophysical processes, or environmental dynamics, and work synthesizing economic, political, social, and cultural mechanisms, or human-societal dynamics. These domains cut across and draw from the concerns about place embedded in geography's way of looking at the world.
This branch of the discipline reflects, perhaps, geography's longest-standing concern and is thus heir to a rich intellectual tradition. The relationships that it studies—the dynamics relating society and its biophysical environment—today are not only a core element of geography but are also of increasingly urgent concern to other disciplines, decision makers, and the public. Although the work of geographers in this domain is too varied for easy classification, it includes three broad but overlapping fields of research: human use of and impacts on the environment, impacts on humankind of environmental change, and human perceptions of and responses to environmental change.
Human actions unavoidably modify or transform nature; in fact, they are often intended specifically to do so. These impacts of human action have been so extensive and profound that it is now difficult to speak of a "natural" environment. Geographers have contributed to at least three major global inventories of human impacts on the environment (Thomas, 1956; Turner et al., 1990; Mather and Sdasyuk, 1991) and have contributed to the literature of assessment, prescription, and argument regarding their significance. Studies at local and regional levels have clarified specific instances of human-induced landscape transformation: for example, environmental degradation in the Himalayas, patterns and processes of deforestation in the Philippines and the Amazon, desiccation of the Aral Sea, degradation of landscapes in China, and the magnitude and character of pre-Hispanic environmental change in the Americas.
Geographers study the ways in which society exploits and, in doing so,
Citations in this section do not refer to major research contributions since these are the focus of Chapter 5. They refer the reader to books and articles that provide a more detailed discussion of the topic than can be provided here.