On Jan 31, 2007, at 14:50, Doug Orleans wrote:
Again, we are in absolutely no danger of running out of oil for
thousands
of years.
Thousands? I thought current conservative estimates were between 50
and
200 years.
My understanding (mostly based on reading John McCarthy's site) is
that the 50-200 years estimate is when the reserves will run out. But
"reserves" just means oil that is profitably extractable at current
prices. There's an order of magnitude more oil that is extractable
but costs more to extract than it would be worth at current prices.
McCarthy also says this:
"Q. When will we run out of oil?
A. Twenty years ago, I had been convinced that by the end of the 20th
century we would be out of oil directly pumpable from the ground.
Obviously, we aren't, and I am cautious about how much oil there is
left. Maybe 20 years, maybe 50 years, maybe 100 years, but I can't see
it lasting longer than 100 years.
However, oil can be extracted from oil shale, from tar sands (as it is
in Alberta, Canada) and synthesized from coal. These processes (except
for tar sands) are too expensive to compete with just letting it just
flow out of the ground in Saudi Arabia, but the technologies were
developed when it was thought oil would run out soon. The costs would
be affordable. Taking these sources into account we probably have
several hundred years supply of oil, provided "greenhouse" warming and
soot pollution permit its continued use."
I contend that even John McCarthy's estimate is in the hundreds, not
thousands, of years.
:-j