From Wiki.
Peak oil, an event based on M. King Hubbert's theory, is the point in time when the maximum rate of extraction of petroleum is reached, after which it is expected to enter terminal decline.
This is worrying in terms of climate change because "difficult to harvest" usually means "energy-intensive to harvest." For example, tar sands require expending around 20-30% of their energy content to extract them in usable form, which means that CO2 emissions from burning that oil are effectively 20-30% higher.
If peak demand means we'll be able to leave the most difficult oil in the ground, that's excellent news.
Good note. Oil is fairly inelastic. I would say terminal velocity on that would be just before it costs the same amount of energy to extract energy. That can be converted to dollars just as well. That's a good thing about renewable and alternate energy, it erodes that inelasticity so when terminal velocity hits, we aren't all breeding horses again.
Some of the $3trn shows up as assets in pension funds and SWFs, but much of it is hiding in the balance sheets of oligarchs and middle eastern monarchs.
I'm not sure how likely/unlikely this is, but that's the theory.
https://www.theguardian.com/environment/2014/mar/06/could-fo...
Hm.
Overall, this should be considered a good thing.
As people convert to alternatives which are cheaper - due to renewables improving - the demand for oil in some industries decreases. Which then drives further innovation into those areas and further alternatives. In fact, this is exactly what critics of peak oil have been saying for years.
(This isn't saying demand for oil will go to zero, just that it is likely to start decreasing.)