If energy can neither be created nor be destroyed then why we worry about our energy resources?

If energy can neither be created nor be destroyed then why we worry ab

1.	If energy can neither be created nor be destroyed then why we worry about our energy resources?
Answer» Energy comes in different form and one can be converted into another form. For example if we light a candle the process is highly exothermic in which chemical energy in candle changes into heat and light energy on burning. The total energy during the physical and chemical process remains the same but we cannot put together the heat and light generated along with products of the reaction to get back the chemical energy in the form of wax. Hence the energy in the usable form dissipated in the surroundings in less usable forms.So the sources of energy we used to do work is consumed and cannot be used again. Because according to law of thermodynamics the energy gets used up in form of heat this energy can never be regained back again thus we actually need tonworry about it