Pollution

• Petroleum generates the greenhouse gas carbon dioxide, and contains sulfur, which, when burned, causes acid rain. This sulfur mixes with atmospheric moisture and destroys forests, rock and buildings. Petroleum production produces large quantities of smoke, which contains harmful gases, such as hydrogen, carbon dioxide and carbon monoxide, which pollutes the air. It is believed that petroleum use is a main cause of global warming.
  
  

Sustainability

• Petroleum is a nonrenewable fuel, and its creation is part of a natural process that took millions of years to complete: Once it is gone, there is no more. Reliance on petroleum is not sustainable. As the world's known oil supplies are depleted, additional oil reserves are sought. This is a costly, ongoing process, with no guarantee of success.
  
  

Oil Spills

• Because petroleum is commonly shipped by sea and drilled offshore, damaging oil spills are always possible. According to the Fossil Fuel website, oil spills are rare, but when they occur, and the damage to marine life, coastlines and birds is often catastrophic. The results of oil spills endure for many years, affecting health and economic issues as well. In the continuing search for oil reserves, the 2010 Gulf of Mexico oil spill is a reminder of this potential danger.
  
  

Political Disadvantages

• Petroleum is mostly found in politically unstable areas, with 70 percent of the world's known oil believed to be in the Middle East. This fact contributes to political unrest and military actions as petroleum-dependent nations make policy decisions in the attempt to control oil production and curry favor with oil-producing nations. The political influence of big oil also affects home-based policies. According to PBS, the oil industry gave $67 million in campaign contributions between 1998 and 2004.