• An oil refinery operates 24 hours a day.OIL image by brelsbil from Fotolia.com
  
  People are dependent on oil to produce energy for many uses. It becomes the gasoline that fills our tanks, fuel for airplanes and electricity that powers our homes and businesses. Much of our economy depends on the drilling and purchasing of this natural resource. Many are proponents of switching to more efficient and cleaner sources of energy.
  
  

Origin of Oil

• Crude oil is often referred to as a "fossil fuel" because it is formed from the remains of dead plants and animals that are millions of years old. Over the course of time, these remains were covered with layers of sand and sediment. Heat and pressure help turn the deposits into crude oil and natural gas.
  
  

Uses of Oil

• In the United States, electricity and other commercial and residential uses accounted for a total of 9 percent of oil consumption as of 2009, Low Impact Living reported, based on information from the Energy Information Administration's Annual Energy Review. Industrial production, from factories and power plants, accounted for a quarter of all oil consumption. The majority of our oil, 66 percent in 2009, is burned for transportation purposes.
  
  

Top Producers

• The top five countries producing oil as of 2009 were Saudi Arabia, Russia, the United States, Iran and China, reported Nation Master, citing The World Factbook. This accounted for 43.2 percent of the world's oil. In 1973, the U.S. was the top producer, leading the former U.S.S.R, Saudi Arabia, Iran and then China.
  
  

Top Consumers by Nation

• The United States was the top consumer of oil at 20.68 million barrels of oil per day in 2007, the latest year for which these data were available, Nation Master reported. The next highest consumer was China at 7.58 million barrels of oil per day. Saudi Arabia, the top producer, ranked ninth among consumers at 2.31 million barrels of oil per day. This was just 11.18 percent of the U.S.'s consumption.
  
  

Top Consumers Per Capita

• As of 2007, the United States ranked 23rd among nations in per capita consumption at 68.67 barrels per day per 1,000 people, Nation Master reported. This ranking was in spite of the U.S.'s leading the world in total consumption. The Virgin Islands led all other nations at 845.38 barrels per day per 1,000 people. Gibraltar was second at 809.94 barrels per day per 1,000 people.
  
  

Strategic Petroleum Reserve

• The United States government oversees a series of underground caverns that comprise an emergency supply of crude oil, known as the Strategic Petroleum Reserve. The storage capacity for these caverns is 727 million barrels of oil. As of December 2009, the Strategic Petroleum Reserve was nearly filled at 726.6 million barrels of oil.
  
  

Environmental Effects

• The burning of oil produces carbon dioxide that pollutes the atmosphere. Every gallon of gasoline burned releases 19 pounds of carbon dioxide into the air, contributing to greenhouse gases, according to Low Impact Living. In addition to this, oil spills periodically contaminate the ocean. In April 2010, for example, a broken British Petroleum pipe caused a massive leak in the Gulf of Mexico, releasing millions of barrels of oil. Such spills can create a ripple effect as the oil spreads, making the ocean toxic for sea life and creating unpredictable shifts in ecosystems.