Nonrenewable Energy Resources

Nonrenewable energy resources exist in limited quantities and, once used, cannot be replaced except over the course of millions of years. Nonrenewable energy resources include oil, natural gas, coal, and uranium. Such resources are currently being used much faster than they can be replaced, creating concern about how long they will last.

Oil, natural gas, and coal are known as fossil fuels because they were formed underground from the remains of once-living organisms. Currently, fossil fuels account for the great majority of the world's energy use. These fuels are not distributed evenly throughout the world. For example, about 60 percent of known oil supplies are located in a small area in the Middle East. The United States has just 2 percent of the world's oil supplies but about 25 percent of the world's coal supplies. Fossil fuels are relatively inexpensive and are usually readily available, but their use creates pollution.