"Oil production technology is giving us ever more expensive oil with ever diminishing returns for the ever increasing effort that needs to be invested," writes Raymond Pierrehumbert, basing his assessment on American Geophysical Union (AGU) data on the untapped shale oil reserves of the United States.
According to the AGU, there are under 3 trillion barrels of shale oil in the U.S. with a 1-2% recoverability rate. Oil trapped in shale formations requires breaking up the substrate or heating it to high temperatures.
While oil industry advocates predict endless oil abundance, geophysical data suggests the opposite scenario. Roughly 1/3 of U.S. shale oil reserves would meet consumption needs for only two years based on 2011 rates. Drilling frequency has increased five times since the year 2000, but the returns have remained static.
The U.S. is also unlikely to surpass Saudi oil production, which exceeds U.S. production by 3.5 million barrels a day.
While high oil prices can spur improved drilling technologies, they also can deplete the resource more rapidly. Because of market and environmental concerns - extracting all the oil from U.S. shale reserves would increase global temperatures by 2 degrees Celcius - the AGU predicts that these deposits will remain inaccessible.
Pierrehumbert holds out hope for improved and efficient extraction in the future and cautions against developing unconventional oil reserves like Alberta's tar sands now, while recognizing that fossil fuel dependence is not a long-term plan.