‘Earth system’ is a term that articulates how the Earth functions as a whole, that is, how each subsystem of the Earth is integrated and interdependent upon the other subsystems of the Earth. Another way of communicating this concept is to point out that every physical, scientific action displayed on the Earth, causes physical reactions within the other aspects of science on the Earth. We call the whole of these physical actions and reactions ‘Earth system science’.
The reason that we must consider the Earth as an entire system, is that every system is both affected and dependent on the other systems. For example, the geosphere, biosphere, hydrosphere, and atmosphere are the four major systems. The hydrosphere consists of all the water, in all forms, that is located on the Earth. The biosphere includes all life on the Earth. The biosphere can't operate and/or even exist without the hydrosphere, for all life (bio) requires water to live. So, the biosphere is completely dependent upon the hydrosphere. Likewise, the atmosphere, which is the layer of gases that stretches around the entire globe, is a necessary component if the biosphere is to continue in existence. For without the atmosphere, the sun’s heat would scorch all life on the Earth (the biosphere), its radiation would burn everything up, and life on the Earth would probably eventually cease to exist altogether. The biosphere is wholly dependent upon the atmosphere, just as it is utterly dependent upon the hydrosphere.
Likewise, without the protection of the atmosphere, the hydrosphere would likely disappear, or at least change drastically. Thus, without the hydrosphere, the biosphere would in turn, vanish, because, as already stated, life (bio) requires water to live, and of course, life also requires the protection of the atmosphere.
Now, we haven’t yet talked about the geosphere, which is the land itself. Imagine how dry the geosphere would be without the hydrosphere continually dropping water on it. Likewise, imagine where we human beings (part of the biosphere) would be in if we didn’t have a chunk of solid land to live on. Lots, if not all, of the biosphere requires land (geosphere)… this includes all kinds of sea life, which, like all life on the Earth, needs to eat. Are not minerals the building blocks of life? And where do minerals come from? The geosphere. So, in one way or another, the entire food chain seems dependent upon the geosphere, and without the geosphere would not the minerals required to sustain life, and thus the entire biosphere, cease to exist?
In summary, a chain is only as strong as its weakest link. Earth system science is a chain, and each of these subsystems is linked within that chain. One weak link can destroy the whole chain.
- Helmenstine, A. M. (2019, December 10). What Would Happen If Earth's Atmosphere Vanished? Retrieved March 12, 2020, from https://www.thoughtco.com/if-earths-atmosphere-vanished-607906
- Tarbuck, E. J., & Lutgens, F. K. (2018). Earth Science. NY, NY: Pearson.