USGS world petroleum assessment 2000; new estimates of undiscovered oil and natural gas, including reserve growth, outside the United States

Oil and natural gas account for approximately 63 percent of the world’s total energy consumption. The U.S. Geological Survey periodically estimates the amount of oil and gas remaining to be found in the world. Since 1981, each of the last four of these assessments has shown a slight increase in the combined volume of identified reserves and undiscovered resources. The latest assessment estimates the volume of technically recoverable conventional oil and gas that may be added to the world's reserves, exclusive of the United States, in the next 30 years. The USGS World Petroleum Assessment 2000 reports an increase in global petroleum resources, including a 20-percent increase in undiscovered oil and a 14-percent decrease in undiscovered natural gas compared to the previous assessment (table 1). These results have important implications for energy prices, policy, security, and the global resource balance.