Thanks for the clarification. You've clearly given this a lot of thought. I like that you are not predicting an imminent demise that none of us can escape, but rather a creeping decay of FF infrastructure and the geopolitical systems that depend on it, due to increasing oil price. And we agree that AGW is a wild-card for which there will be no easy fix, on top of PO.
I guess we disagree on the speed at which oil prices will rise, due to new extraction technology and resources being developed, and how fast demand will increase, due to a new price regime and associated eff gains (like the US doubling our fleet mpg, if we can pull that off). I think this is what energy transitions look like. And why they take so long.
I am also not getting your numbers. The cost of FF is not 100% of the cost of food, so I don't see why 4X the cost of oil would quadruple the price of food. It is only ~50% of the cost of civil aviation, so the cost of flights would double. Tires I don't know, but they already last 50k miles, so $1600 for a set of 4@$400/bbl, adds $0.03/mile.
And more to the point, I think coal-to-liquids would kick in around $200/bbl sustained price. And while I am concerned about AGW, CTL would only be for the marginal production and wouldn't boost the average footprint of an oil barrel significantly.
As for population, it is well established that the developed world has been at or below pop replacement levels for some times. Does that count? The US is an outlier, but our pop growth is mostly from immigrants and their children born here. China has huge demographic problems, but they do not suggest a surge in population over the next few decades. India bears watching.
The cost of food is clearly a major limit/issue. But it bears noting that staple crop prices have been falling over the long term:
http://earlywarn.blogspot.com/2011/03/long-term-crop-prices.html
When LTG came out in the 70s, the cost of staple crops were ~2X
higher than they are today. During the 40s and 50s they were 3X higher than today. Of course, my parents reminded me that lots of people were starving back then, so I should clear my plate. But doubling the current staple crop price? Tripling it? Even if it happened, most people would adapt (to mid 20th century prices) and in some parts the developing world, more people would starve, maybe.
I should look more into the new 'cheerier' Club of Rome guys. The little I have read from them sounds pretty grim compared to 'conventional economics', a significant reduction in standard of living, energy services, industrial output per (world) capita by 2050, with AGW starting to bite. And that is their BEST case scenario, not the business as usual approach which is super-grim. From my POV, those pathways sound a lot like the ones you describe, not collapse in 2015 and stone age in 2020, but a choice of grim and grimmer decades ahead based upon the wisdom of our collective decisions/war/etc.
The upnote is of course, in a world where per capita 'stuff' and energy is half what it is today, it is possible, esp for folks that still have money, to put together satisfying and happy lives. Unlike the worst predictions of 2005 PO, we will not all spend our days wandering around grubbing tubers out of the ground and sleeping is dead SUVs. As for the world beyond 2050 (or 2100), sure there are deep sustainability challenges, but our imagination is limited IMO. Do you worry about AIs?
And I think offering a 'more positive' message is a very good idea. The old CoR message was 'you can't escape collapse'. The new one is 'if you do xyz, then our children can put together decent lives that they can enjoy' and most of 'xyz' sounds like sensible AGW prevention, increase eff, soil preservation, etc. Reasonable stuff. I think it will sell a LOT better to the millennials than the old message did to the boomers.