Fundamentally, geology is the study of the Earth. This includes rocks and fossils, but also groundwater, streams, oceans, natural hazards, and environmental issues. Many of these are viewed in the context of plate tectonics, which explains why earthquakes and volcanoes are found in particular locations and helps us forecast future changes in the oceans, atmosphere, and ecosystems. On the economic front, modern civilization would not exist without the many earth materials mined and extracted from its surface and underground. The most valuable is by far petroleum, but geologists also seek the rare earth elements used in cellphones, displays, computers, and solar cells. Modern technology would quickly cease to exist if geologists stopped finding new rare earth deposits. So, whether you consider environmental remediation or rare earth mining, geology is a very practical science.
The environmental sciences generally focus on applied issues related to human interactions with the Earth and its ecosystems. These interactions are physical, chemical, and biological. As a result, the environmental sciences draw upon the whole of geology, as well as biology, chemistry, and atmospheric sciences. Environmental geologists deal with the positive and negative aspects of the interactions. On the positive side, environmental geologists seek the most efficient, low-impact means to obtain freshwater for human use. On the negative side, these scientists try to contain and correct groundwater pollution problems. Those are only two of the many tasks given to environmental geologists and the field is continually growing and expanding.
At the program level, coursework differs between geological and environmental science majors. Geology majors take advanced courses in earth materials (e.g., rocks), long-term evolution of earth’s physical, chemical, and biological systems, and our planet’s interior workings. Environmental majors take a different suite of advanced courses. These include courses in the flow of water underground and surface and subsurface waters chemistries. Importantly, geology and environmental majors can take each other’s advanced courses as electives.