Despite major oil finds off Brazil's coast, new fields in North Dakota and ongoing increases in the conversion of tar sands to oil in Canada, fresh supplies of petroleum are only just enough to offset the production decline from older fields. At best, the world is now living off an oil plateau—roughly 75 million barrels of oil produced each and every day—since at least 2005, according to a new comment published in Nature on January 26. (Scientific American is part of Nature Publishing Group.) That is a year earlier than estimated by the International Energy Agency—an energy cartel for oil consuming nations.
To support our modern lifestyles—from cars to plastics—the world has used more than one trillion barrels of oil to date. Another trillion lie underground, waiting to be tapped. But given the locations of the remaining oil, getting the next trillion is likely to cost a lot more than the previous trillion. The "supply of cheap oil has plateaued," argues chemist David King, director of the Smith School of Enterprise and the Environment at the University of Oxford and former chief scientific adviser to the U.K. government. "The global economy is severely knocked by oil prices of $100 per barrel or more, creating economic downturn and preventing economic recovery."
Nor do King and his co-author, oceanographer James Murray of the University of Washington in Seattle, hold out much hope for future discoveries. "The geologists know where the source rocks are and where the trap structures are," Murray notes. "If there was a prospect for a new giant oil field, I think it would have been found."
King and Murray based their conclusion on an analysis of oil data from the U.S. Energy Information Administration. Looking at use and production trends, the two note that since 2005 production has remained essentially unchanged whereas prices (a surrogate for demand) have fluctuated wildly. This suggests to the authors that there is no longer any spare capacity to respond to increases in demand, whether it results from political unrest that cuts supply, as in the case of Libya's political upheaval last year, or economic boom times in growing countries like China. "We are not running out of oil, but we are running out of oil that can be produced easily and cheaply," King and Murray wrote.
Other statistics, however, argue against a plateau. Oil company BP found in its most recent analysis that oil production was actually more than 82 million barrels per day in 2010, higher than the proposed plateau of 75 million. That difference may be the result of the increasing use of "unconventionals"—Canadian tar sands or the natural gas liquids co-produced with oil extraction. Rising production in the China, Nigeria, Russia and the U.S. also hints that technological improvements may allow greater production from existing fields than the new research suggests.
Plus, the price of oil may argue against any such plateau. Adjusted for inflation, today's $100 per barrel is roughly equivalent to prices in 1981, according to environmental scientist Vaclav Smil of the University of Manitoba. Smil also notes that in the last 20 years enough oil has been found to satisfy the demands of two new consumers—China and India—nations that now import more oil than is consumed by Germany and Japan.