Fossil fuels are often described as non-renewable energy sources.
what are they called 'non-renewable'?

Non-renewable energy comes from sources that will run out or will not be replenished for thousands or even millions of years. Most sources of non-renewable energy are fossil fuels. Fossil fuels were created as the remains of marine creatures decayed millions of years ago, under huge amounts of pressure and heat.

Explanation:

affects the water bodies: excessive use of fertilizers causes eutrophication. the fertilizers which are used on plants affect the quality of land on which it is used, further causing erosion of soil. the fertilizers used on plants contain harmful chemical fumes which affect the environment.

when it is at an intermediate population density