The four main spheres of earth are the

The four main spheres of earth are lithosphere (geosphere), hydrosphere, biosphere, and the atmosphere.

Explanation:

Each of these four spheres represent an element. If one little thing happens, it could change the way the four spheres work together. The four spheres work together to make everything in the earth to keep moving. The hydrosphere represents any form of water, the geosphere represents and form of land or the rigid outer part of the earth such as mountains and rocks, the biosphere represents all living things such as animals and plants, and finally the atmosphere that represents gasses surrounding the earth such as carbon dioxide and oxygen.

Hope this helps!