First part is here.
An oversimplified, drive-by version of the changing role of physical geography includes these overlapping and not mutually exclusive stages:
1. Discovery and exploration—collecting basic data and observations on topography, geology, biota, meteorology, oceanography, etc., often in conjunction with surveying, mapping, and collection of anthropological and economic data. In this stage physical geographers are simply, but not exclusively, Geographers. They are also, in various cases, anthropologists, biologists, ethnographers, geologists, meteorologists, oceanographers, and surveyors.
2. Holding up the Earth and environmental sciences end of the integrated geographical analysis of places, regions, and various geographical systems (e.g., transportation and settlement patterns, trade networks, cultural landscapes, climate zones, biomes, agricultural systems, etc.). Physical geographers in this stage were either specialists in the physical side of the discipline, or broadly trained geographers with substantive physical expertise.
3. Holding up the spatial analysis and integrative environmental sciences end of climatology, geomorphology, pedology, hydrology, ecology & biogeography. The main role of physical geographers was in making distinct contributions to the subdisciplines using perspectives and methods often neglected by non-geographers.
4. Functioning as specialists within both traditional (e.g., fluvial geomorphology, hydroclimatology, plant geography) and new or emerging (e.g., landscape ecology, global climate modeling, Earth system science) subdisciplines, somewhat independently of institutions and organizations of geography or other traditional disciplines.1 In this, the current stage, institutions associated with traditional disciplines persist and exert important political, social, and economic influence on Earth and environmental sciences. However, with respect to the actual practice of research and discovery, traditional disciplinary boundaries are increasingly irrelevant, and inter-, multi-, and transdiscplinary approaches are common.
In the current stage 4, the scientific community at large has recognized the necessity and value of geographical perspectives and methods, such as integrated environmental science, spatial analysis and modeling, and mapping sciences. Just as researchers invent or adapt mathematical or statistical methods to suit their needs, often without the direct inputs of mathematicians or statisticians, or develop computer code without computer scientists, Earth and environmental scientists now improvise and innovate “geographical” methods without direct involvement of individuals trained as geographers. Geography is more important than ever, and thus so are (physical) geographers. But the extent to which we will continue to be identified as such (by ourselves or others) remains to be seen.
1Somewhat independently means that individuals interact across academic units, professional organizations, and journals associated with two or more traditional disciplines, or newer non-traditional (sub) disciplines. By traditional disciplines I mean university academic departments as they commonly existed in most of the 20th century—geography, geology, biology, oceanography, soil science, forestry, etc. This is in contrast to more recent constructs or interdisciplinary banners such as Earth system, environmental, ecosystem or climate science; landscape ecology; critical zone studies; surficial processes, water resources, etc.