Making oil requires a specific series of geological accidents over
inconceivable amounts of time. First, organic-rich sediment needs to
be burried faster than it can decay. Then the stuff needs to get pushed
miles down into the earth's crust to be cooked slowly. Burried too
deep or cooked too fast and the organic molecules burn off;
trapped too shallow or not for long enough and the muck never
turns into oil. Finally, an impermeable layer needs to seal the
oil in a porous layer of rock from which it can be recovered. Then
somebody has to find it and get it out of the ground. It takes
millions of years to produce a barrel of oil; we use millions of
barrels a day. There is no question that we will run out of oil ---
the only question is when.

