Peak Oil - in brief

"Peak Oil" refers to the maximum extraction rate of oil, after which the rate of extraction will decline. It has been found that the extraction of oil always follows a more or less bell-shaped curve: first the oil is discovered and once it starts to be pumped out, the rate increases steadily until it reaches a peak, after which it becomes impossible to pump at the same rate: production will inexorably decline. World discovery of oil peaked in 1964 and has been declining ever since - despite considerable improvements in technology - and there is no prospect of any significant large discoveries. We are currently consuming more than six barrels of oil for every one that we discover. There is a growing consensus that we are now approaching, or are even at, the world oil peak. More on peak oil at Wikipedia.