Human population on earth has been increasing from centuries and with increase in population consumption of natural resources increasing rapidly.
Natural resources which are available on earth can be divided into renewable and non renewable sources. Renewable sources include water, air, sunlight etc which are basic necessities of life. Non renewable include fossil fuels, wood and other products.
With evolution of mankind, man has learnt to utilize the renewable and non renewable sources of energy. And energy needed for the other activities have increased hence fossil fuels is used as the major source for production of energy.
But excess use of the fossil fuels poses threat to the mankind by polluting the natural sources. Energy produced by the non renewable sources of energy is unsustainable source and these fossil fuels are going to degrade soon or later depriving mankind from its major sources of energy.
The above infograph explains you about the usage of fossil fuels.