Petroleum is a non-renewable resource, because the natural petroleum deposits are finite and, once exhausted, there is no way to restore them. As of 2014, the Earth possesses several decades of petroleum resources to meet its needs.
The human population is shifting away from non-renewable energy sources due to the increase in awareness of harmful pollution and depleting resources. Renewable energy sources, on the other hand, can be replenished once used. Examples of such resources are solar power, wind-generated power and bio-fuels. In addition to being sustainable, these resources tend to be cleaner and are less harmful to the environment.