Non renewable as the word itself states that it’s simply a depleting source as we go on utilizing. The fossil fuels are formed from plants and animals deposits in sedimentary layers which lived 300 million years ago. Almost every form of energy requirement demands are met by combustion of these fossil fuels. The decomposed plants and animals within sedimentary layers convert into handy fuels like compressed natural gas, mineral oils and coal. These are categorised as non renewable as these process can’t be reprocessed or repeated again and once used its lost for ever and;These form of fuels are non sustainable as the residues of these fuels led to pollution and accumulation of greenhouse gases Non-renewable energy is sourced from fossil fuels which are formed due to the piling of rocks and sediments over dead plants and animals perished millions of years back. Due to high pressure and temperature the plant and animal deposits slowly turn into petroleum products and other gaseous fuels and;These are termed non-renewable as the fuels that are obtained can’t be harnessed overnight and neither the process of converting plants and animals carcass into handy fuels can be done in any industry as well. These are slow bio-chemical process which turns these plants and animal deposits under sediments into handy fuels. Nothing could be renewed as these processes are irreversible and hence the clock can’t be set right Most of the non-renewable fuels turn into greenhouse gasses and yet few others go into atmosphere and come down in form of dilute acid rain. . . . . . . . . . .