hardest types of coal, bituminous and anthracite, are used in
the burning of coal. These forms of coal are fairly prevalent.
They are mined by strip mining or digging down into coal veins
with the raw material then being transported to the surface for
refinement. Coal is not clean burning, very efficient or
environmentally friendly. The material is also very hazardous to
the miners given the dangerous work environment and the coal
dust that imbeds in their lungs.
Oil is the most
widely used of the types of fossil fuels. Oil (petroleum) is
found in natural reservoirs underneath the Earth's surface.
Pumps and piping are drilled down underground to reach these
stores of oil, and then it is pumped up to the surface. Crude
oil is then refined for use as heating oil, gasoline and many
other combustible fuels. Oil's portability and easy to burn
properties make it an excellent source of energy. The burning of
oil has a number of drawbacks. It produces significant air
pollutants and carbon dioxide, which is a greenhouse gas.
Furthermore, oil reserves are not spread equally over the
planet, giving rise to political and military tensions
associated with the control of the resource.