Oil is a popular and readily available energy source, but it does have its downsides. Although it is relatively inexpensive when compared to renewable forms of energy production, such as solar and wind power, burning oil generates several types of pollution. Technological advancements are improving access to oil reserves, but the global supply of oil will eventually run out because it is a nonrenewable resource.

Pro: Available and Inexpensive

Several countries produce and refine oil, so the infrastructure for global distribution is already in place. Because it is a liquid, oil can easily be transported through pipeline networks, which move a large amount of oil over great distances relatively quickly. Most buildings and vehicles are made to work with energy generated by oil; the infrastructure exists to connect new buildings to power created by oil-burning power plants and gasoline is the most widely available fuel for vehicles. In contrast, alternative energy sources often require a significant initial investment to install the necessary equipment.

Con: Environmental Damage

Greenhouse gases, including carbon dioxide, methane and nitrous oxide, are released into the atmosphere when oil is burned. These gases trap heat in the atmosphere and cause changes in climate that raise sea levels, alter weather patterns and force species to migrate. As an energy source, oil causes several kinds of air pollution, in addition to polluting land and water when it leaks or spills. Massive spills, like the 2010 Deep Water Horizon spill in the Gulf of Mexico, have disastrous consequences for the environment, human health and the local economies that depend on fisheries and tourism.

Pro: Efficient Energy

Almost 50 percent of the oil used in the United States is sold as gasoline. While gasoline alternatives such as ethanol and biodiesel exist, most vehicles need to be modified to use them. Existing infrastructure and vehicle design make oil a convenient energy source. Also, oil's chemical composition makes it an efficient energy source. No other kind of transportation fuel contains as much energy per unit of volume as gasoline and diesel, according to the U.S. Energy Information Administration.

Con: Finite Resource

Oil is made when organic matter is subjected to tremendous heat and pressure for millions of years. It is not a renewable resource, so the global supply of oil will eventually be depleted. The U.S. Energy Information Administration projects that, based on known oil reserves in 2013, the oil supply will last until approximately 2063. Eventually, reliable alternative energy sources need to be developed; several, including solar, wind and geothermal power, are becoming increasingly more convenient and affordable.