Fossil fuels are currently used as the primary energy source for the world. They are formed over millions of years from organic materials in the Earth. Fossil fuels are considered to be non-renewable resources that were formed or created when prehistoric plants and animals died and were gradually buried by layers of rock.Examples of Fossil Fuels:1. Coal: It is the primary fuel for the production of electricity . The burning of coal and the mining process is harmful to the environment releasing air pollutants such as sulfur dioxide, nitrogen oxide, and mercury.2. Oil: Oil is the primary source for the world\’s transportation. Most oil is pumped out of underground reservoirs but may also be found in shale and tar sands. The crude oil is then refined to create the fuel such as heating oil, gasoline, petroleum gas, pesticides, fertilizers, plastics, and more.