Sources of energy that cannot be depleted, but can be replaced, recycled, or renewed by natural processes or the environmental cycle are known as renewable sources of energy. Non-renewable sources of energy, on the other hand, are those that cannot be reproduced, and once used cannot be replaced. These are formed naturally over a period of millions of years and therefore, they cannot be replaced easily. Moreover, there is always a danger of these resources getting extinguished. Hence, they are also known as exhaustible resources. Due to this fact, conservative use of these resources is the need of the day. Researchers are in a process of finding substitutes that will replace these resources, but until then it is our responsibility to use these non-renewable resources carefully and wisely. About 85% of the world's energy comes from non-renewable sources of energy, if we happen to use these resources at this rate; it will only intensify the entire problem further. A list of non-renewable resources is given below, which as a result of continual use may no longer exist and humanity will have to find alternate sources of energ
