Fossil fuels were produced from the remains of ancient plants and animals. There include coal, petroleum(oil)and natural gas.Apart from its use in vehicles, many of the products we use today are made from petroleum. There include plastics, synthetic rubber, fabrics like nylon, medicines, cosmetics, waxes, cleaning products, medical devices etc. we need to conserve fossil fuels so we don't run them. However, there are other good reason the pollution caused by them when burnt, to limit our fossil fuel use. scientist are exploring alternatives to fossil fuels.