Peak oil is an important concept but it often seems misunderstood.
Peak oil being passed does not mean oil will be unavailable immediately, which I have read people as saying. These statements then seem to lead to people arguing that because we have oil, peak oil is not a problem.
Some of this argument appears to come from the theology of the magic of The Market. The Market as god, is always supposed to produce what we need, without us having to prepare for market failure, market self-destruction, or simply running out of supplies on a finite world.
Predictions in brief
A 1956 world oil production prediction, based on historical data and future production, proposed by the geologist M. King Hubbert, had oil production peaking at 12.5 billion barrels per year in about the year 2000. This figure has been exceeded recently.
According to wiki, in the 1970s-1980s Shell, Exxon, the UK department of Energy and the World Bank, predicted peak oil would hit in the early 2000s, and the previous article I wrote gives some evidence that production has started to decline.
Oil production peaking does not mean that after we reach ‘peak oil’, there will be no oil available at all, just that it will be harder to obtain, and production will eventually start declining. It could even be the case that after peak oil, oil production will increase for a while due to desperation, price increases, or the use of crap fields, and then decline more abruptly.
Plenty of people have said it will take more and more energy to extract new oil when the easiest oil sites have already been found and exploited. And this seems true. No one would use tar sands oil with all its impurities and sludge, if normal oil was easy to find. No one would would be fracking for oil if oil was easy to find, same with deep sea oil. The energy cost and ecological risk of extracting seems to be increasing.
Eventually it is highly probable that the energy cost of obtaining oil will get close to the energy released from the oil being extracted, even if price factors drive the market onwards. When that happens we will be on a collapsing road. However, if ecological damage helps decrease the costs of obtaining oil, we could suspect that ecological damage from oil production will increase. This will have other consequences.
As the system is full of unknowns, the actual date at which oil will cease to be available at all in practical terms is uncertain, but it certainly looks as though we are on the way there.