>> 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. As prices go up, more of this oil becomes profitable to extract. So it's not a matter of running out of oil completely, it's just that it will start to get more expensive once the "low-hanging fruit" has been harvested. (At which point the next-lowest-hanging fruit may well be some other energy source that becomes newly profitable at the higher prices, which would mean it won't matter how much oil is left.) --dougorleans@xxxxxxxxx