One of the biggest disadvantages of using oil is that it is a nonrenewable source of energy, which means that once supplies are exhausted, there is no way to produce more. Oil also poses significant risks to the atmosphere and water bodies; oil spills, for instance, cause disastrous effects to local environments by destroying plants and organisms and are often expensive and time consuming to clean up.
In addition to posing threats to marine life, birds and coastlines, oil releases toxic chemicals into the air when burned. During the process of heating, oil produces carbon dioxide — a greenhouse gas that does not biodegrade when released into the atmosphere. Additionally, oil contains a wealth of sulfur, which creates sulfur dioxide and sulfur trioxide when burned. Upon reaching the atmosphere, these compounds combine with moisture to form sulfuric acid, otherwise known as acid rain. After falling to the surface of the earth, acid rain leaches into streams, reservoirs and other bodies of water.
Oil spills are both costly and deadly. Cleaning up an oil spill uses resources, and many animals in the area can be harmed by the spill. Animals can ingest the oil, and birds' feathers can become coated in oil, causing them to lose buoyancy.
Another disadvantage of oil is that it threatens political stability and national security because most developed nations rely on overseas sources of oil. As oil supplies diminish, competition for the remaining reserves becomes more fierce.
Lastly, many products derived from oil provide benefits to humans but are also toxic.