Introduction The earth functions as a unit system in space. The authors’ claim that the earth is round but not perfect spheroid, scores the credibility of all scientific observations. The earth is further subdivided into four interrelated subsystems. The four systems comprise the lithosphere, atmosphere, hydrosphere, and Biosphere. These spheres of the earth interact through various processes, which include energy transfer and air circulation. The four subsystems and their interrelationships The lithosphere defines land and all associated resources while all the water bodies of the earth make up the hydrosphere. Similarly, the biosphere refers to the subsystem occupied by all living matter on the earth’s surface and the ground beneath it. Finally, the atmosphere covers all the gaseous materials that cover the earth. All the four subsystems interlock each other in well-defined ways. Thus, living matter on the earth obtains oxygen from the atmosphere while condensation in the same sphere results in precipitation on the lithosphere. Again, in the hydrological cycle, evaporation from the hydrosphere and evaporation through transpiration from the biosphere in the lithosphere leads to the formation of clouds that return to the lithosphere through precipitation (Gabler, Petersen & Tropasso, 2007, p. 13) The synergies created by perpetual interaction within the four main subsystems of the earth also result in replenishing a number of resources useful to both people and animals on earth. For example, from the atmosphere, people get fresh oxygen used in respiration and other important gases used in industries. Besides oxygen, we may consider oxygen obtain from the atmosphere through fractional distillation of air and then used as a preservative in food and beverage processing. On the other hand, oxygen, which comprises the main resource from the atmosphere supports combustion and is therefore used in the burning of material to facilitate molding them into different shapes (Strahler & Merali, 2008, p. 6). From the hydrosphere, people get both fresh and salty water. Salty water covers nearly 67% of the total water volume on the earth. However, freshwater that makes up to 16% of the earth’s total water by volume forms the primary resource in both domestic and industrial activities. At home, people drink fresh water to quench thirst while all households depend on water for cooking and a wide range of cleaning. In the real of biosphere and hydrosphere interaction, people find a variety of aquatic animals. The edible species of aquatic animals such as fishes make delicacies in most maritime communities and amongst people living in inland waters (Strahler & Merali, 2008, p. 8). The aquatic animals also contribute to the economic well-being of most traditional societies that practice fishing as means of generating revenue. In most locations where people live on the coastlines, large-scale fishing provides an important source of government revenue and food for the population. On the lithosphere, people find the land to walk and carry out all other activities (Gabler, Petersen & Tropasso, 2007, p. 13). The two main resources found in these spheres with crucial benefits to people are vegetation and rocks. From the rocks, people get minerals