Sir, the Times incorrectly reported that Greenland has 47 billion barrels of ‘estimated oil reserves’ (‘Global warming could help Greenland to independence’, 7 May), which is wrong on two counts.

First, the 47 billion estimate comes from a study by the United States Geological Survey published in 2000 which estimated not reserves (amounts of oil that have been proved to exist by exploration), but the amount of oil that might be discovered in future, a much more speculative figure. Second, after gaining access to new geological data, in August 2007 the USGS slashed its estimate for Greenland to less than 9 billion barrels.


The original USGS estimate was part of worldwide oil assessment that has now been widely discredited as wildly overoptimistic. In a further study published in 2005, the USGS was forced to acknowledge that while the original assessment implied worldwide oil discovery of 22 billion barrels per year until 2025, in reality the industry has been finding only 9 billion annually – 60% less than forecast. If this underperformance continues, the USGS global estimate for future oil discovery is 500 billion barrels too high.