- Key facts
- It's a stretch, but imagine you're an Eskimo living 1,500 years ago
- Where does petroleum come from?
- How much energy does petroleum provide?
- How much petroleum is there, and how long will it last?
- Geography is against us
- Where might new oil reserves be found?
- Two unconventional sources of oil: oil shales and tar sands
- Growing worldwide competition for a dwindling resource
- If supplies are dwindling, why watch petroleum go up in smoke?
- Environmental effects of petroleum
- Petroleum exploration versus conservation of endangered species
- The bottom line
How much energy does petroleum provide?
In recent years, the United States consumed about 7.5 billion barrels of petroleum a year, dropping to 7.1 billion barrels 2008. More than 60% of petroleum is imported; 17% of this from the Persian Gulf.4 Petroleum provides about 37% of the world's energy and 41% of the energy used in the United States,5 most of which is used for transportation. The United States alone uses 8.4 billion barrels of oil a year. According to the U.S. Department of Energy, essentially all the energy used in transportation in the United States comes from fossil fuels,6 and two-thirds of all transportation energy in the United States comes from petroleum: 2.2 billion gallons a day—55% (1.2 billion gallons a day) for ground transport of people, almost 36% (789 million gallons a day) for ground transport of freight, and just under 10% (210 million gallons a day) for air transport of both people and freight.7 In contrast, petroleum provides only 1% of the electricity produced in the United States.8 Most electricity in the United States is produced from coal, hydropower, and nuclear power. To keep things simple, think about petroleum as the transportation fossil fuel.