Answer :
In terms of their direct harm to the environment, when we use fossil fuels we burn them, which releases carbon dioxide. This carbon dioxide causes global warming by trapping heat in the atmosphere.
The advantage of the Fossil use in producing fuels is the fact that it is cheaper than alternative forms of energy, its mechanism of use is simpler and Finally, fossils are abundant in nature.
The drawbacks: This source of energy is not eternal, especially with the speed at which we consume it. Another disadvantage is that the use of this source is very polluting.