Your grandmother gives you lot of mangoes and asked you not to eat all alone but also to distribute it to your siblings and cousins. With every person, the number of mangoes you have is decreasing and ultimately you are left with no mangoes.
Your grandmother told you that the result is same for natural resources too. She is right because?
Natural resources will be depleted with coming generation
In the beginning, natural resources were abundant in nature. But as population grew, they started using more and more of natural resources just as mangoes were depleting with every person. In the end just like mangoes, no natural resources will be available. Natural resources are not unlimited.