Question

How are the earth's principal biological system being depleted?

Answer 1

Mr. Lester R. Brown has pointed out that there are four principal biological systems of the earth. They are fisheries, forests, grasslands and croplands. They are the foundation of the global economic system.

Answer 2

Answer:

In large areas of the world, human claims on the principal biological system are reaching such an unsustainable level that their productivity is being impaired.

When this happens fisheries collapse, forests disappear, grasslands are converted into wastelands and croplands deteriorate.Thus the Earth's principal biological systems are depleting day by day.