That sentence is an example of parallel structure.
When there is repetition of a specific grammatical form in a sentence, parallelism or a parallel structure is produced. This occurs when you mantain the same pattern for every compared word or idea in your construction. This makes the idea easier to follow by the reader.
As human populations grow, human demands for resources like water, land, trees, and energy also grow. Population growth has relatively easy and inexpensive solutions and because population impacts every environmental challenge — it is an essential element to achieve sustainability.
