I'm not sure if this helps but I believe that its because natural resources are what make up the earth. So if the earth is missing one, every other natural resource will be missing something they need. For example, wood is a natural resource which comes from trees. Trees need water. Without water, that tree won't grow, and without trees every living thing will die because as science explains, trees give oxygen in replacement of carbon dioxide I believe.
I'm sorry if this is wrong. This is just what I think
