Earth science is a very broad subject which encompasses all of the sciences relating to the Earth, including its environment and the atmosphere. Earth Sciences has three main sub-categories: environmental studies, geology and geography. These three sub-disciplines are all connected to the study of the Earth and thus, are integral components within this category.
Environmental studies is an interdisciplinary subject which places a large focus on analyzing the environmental problems society is facing today and also considers mitigation techniques. The subject of environmental studies is rather multi-dimensional, focusing on both the biological and physical nature of the world, as well as the cultural, political and social forces which influence the environment. Some topics of study encompassed under this subject area include environmental policy (dealing with the political side of environmental analysis and study), global water issues (dealing with the physical world) and conservation issues (dealing with the biological world).
In comparison to environmental studies, geology is a subject area analyzing the physical materials of the Earth, as well as investigating the materials which exist within the atmosphere and in space. Geology studies Earth processes, such as erosion, which have been taking place for billions of years and analyzes how these past processes can be used to make future predictions. Some subject areas which fall under this category include the study of minerals, rock processes and geophysics.
Similar to the former two subject areas, the study of geography also considers the Earth in terms of its physical environment, including the landscape and specific locations. However, geography also hones in on investigating the relationship between individuals and nature. Thus, geography can be categorized as being either physical or human-based. Physical geography considers topics such as atmospheric science and soil science, whereas human geography considers indigenous studies and urban studies, to note a few examples.