How rapidly petroleum products become scarce will determine just how survivable this predicament is for our species. Cold turkey unavailability of oil and natural gas would surely kill most of us. If the oil and natgas really did just suddenly run out, I'd bet within just a few years the only people left would be whatever tribal folk are currently living at a stone age level and who have shunned any form of agriculture. Natural gas may taper out rather suddenly, but oil supplies will decline gradually and coal will be forced into the role of an expensive replacement. Scarcity will be gradual which means we will all get to experience the cloud cuckoo world of rising food and energy prices in the midst of a declining economic activity, job loss and falling wages: stagflation on steroids. Initially the collapse will be felt economically. Consider the hard financial times ahead sort of a prelude. Also consider it a gift. Escalating food and energy prices will act as Adam Smith's much-maligned invisible hand and shove folks however reluctant they may be to leave behind their energy-wasteful ways. This is where we see a permanent decline in the value of the suburban housing in which so many Americans live. People will be walking away from their mortgages becauses the location of their homes will make living there and the attendant driving impossibly expensive. A lot of folks commute to work (I take a train and bus combo for about 20 minutes each way), but not as many then need the car to do things like get to the grocery store. There are communities that are nothing more than a hundred houses or so many miles removed from any food source or commercial activity. It's bad enough that rising transportation costs of getting food from faraway farm to local market will make that food very expensive; imagine then having to burn a quarter gallon of $10/gal gas to get that food from the market to home.
The changes will be gradual. The exurbanites will do all the little things like making less small trips and combining as many activities as possible into the agenda per trip. Eventually, however, the notion of having to drive to do everything will be exposed for the folly it has always been. The exurban living arrangement will cease to be tenable. This is the first physical contraction of megalopolis. The outermost or exurban rings composed of those houses out with the megamalls in what used to be cornfields and nowhere near any old urban development will blow off first. The newer automobile suburbs are next. I consider these to be the suburban sprawl that grew between the small towns that used to comprise the railroad suburbs of the urban core. Eventually, there will be a noticeable decrease in car use and a return to "light rail." The metropolis will be reliant on rail and foot instead of automobiles. If it weren't for the blacktop poisoning of most of the farmland in a hundred-mile radius, I'd be more hopeful about holding the line against collapse here. Sadly, at some point just feeding the people of the shrinking metropolis will become problematic. Surely unecessary amounts of mobility represents the modern era's greatest waste of petroleum-derived energy. Yet natural gas has been feeding and heating humanity. Natural gas augmented the food yield of the soil and without the input of the gas-based fertilizers, less people will be able to be fed. Even if nuclear allows us to keep the lights on, stay warm and get around in a rail-centric metro area, there remains the issue of food production.
Food will get more expensive before there is a sheer starvation-inducing shortage. People won't be able to afford to reproduce. My fear is that we will continue to reproduce in numbers that suggest food surplus. Personally, if I see that I could not afford to feed offspring, I simply refrain from any thoughts of reproduction. If forethought is truly a trait inherent in humanity, then this would be an excellent time for the general populace to start exercising it a bit more assiduously. Nature will surely be exercising her number-culling through her usual kit of starvation and resource war when we fail to meet her depreciation quota under our own cognisance. Before this, however, price inflation for food and energy accompanying a deflation of credit and things that depend on credit like mortgaged home prices. The economic squeeze will force people out from the edges of megalopolis and back toward the nodes of the megacities and suburban town cores. Three generations under one roof may become the norm again. Rail will replace autos. People will have to live in places where getting around on foot is realistic.
Of course I'm supposing that their something to get to such as a job or food market. There's every chance that staying in the big city and suburbs will become so difficult so quickly that people flee back to towns in the midst of farmland. Metroplex living could get increasingly unbearable until a tipping point is reached and absolutely everyone left tries to get out. That's what keeps me up nights more than anything else. I'm pretty sure that my current region will be an unlivable ruin within a decade or so. I have plans to head to a smaller, more salvageable town with farmland, but I wonder how long I have left to make good on my escape plans. I do believe the first years of the collapse (having started somewhere between 2000 and 2005) will be a slow time of gathering momentum. It's like the gods are rocking the boulder back and forth to dislodge it and get it speeding down the mountain toward us. Even when this rock actually gets moving and it becomes obvious that it will strike with deadly force at the bottom of the mountain, it won't be anywhere near top speed during the initial portion of the descent. If I had known about Hubbert's Peak ten years ago when I was first employed, I'd be ready to retreat to a safe zone by now. The seriousness of this situation only became clear to me a couple years back--I initially figured we'd just lose the automobile but keep the megacities--and now I worry about how best to use the remaining time to prepare. How long do I have before my job disappears or before frequent blackouts make my neighborhood dangerous or food becomes scarce? I imagine that things won't get outright scary till after 2008 or so, but that's not far away at all. I certainly don't think I'd want to be living here in 2015.