Reserves of oil are notoriously difficult to measure, but BP estimates that there are proven reserves of approximately 1.24 trillion barrels, and their 2008 Statistical Review of World Energy shows daily consumption running at around 85.2 million barrels, suggesting that the current proven oil reserves will only last around 40 years.

However, consumption levels increased by 1.1% in 2007, and emerging economies such as China and India are increasing this rate still further. New oil fields are being discovered, but they are typically in more remote areas or deeper seams, which has an impact on costs. All this indicates that the price of oil will continue to rise.