To say post-Peak Oil will result in another Great Depression is real crock. 1) The Great Depression was caused by a lack of fluid finances (no paper money available) rather than a resource lack. Farmers in the Midwest lost farms even though they continued to raise sufficient crops - no one had money to buy them. But the government still ran on paying taxes with money, not crates of potatoes or bushels of corn. 2) Doesn't take into account the prolific American innovation tradition. Already we have hybrid gas cars. Already, three acres can produce enough oil to run a family car for over 30K diesel miles a year - match this with hybrid technology and we could double that.
Where you are going to have problems is in the congested cities, where they don't have the resources to feed, clothe or fuel themselves. This is the target area, not rural ones. Rural areas will only have problems if some central government decides to run these areas the same as metropolitan areas. Fuel problems in metro areas would work if they start creating electricity from their garbage and working to grow food with the resultant mulch. Run mass transport with that electricity and you can get something done within cities themselves.
We also have other alternatives, such as making oil from high-sulfer coal or turkey manure (both of which become cheap enough to invest in when Peak Oil starts jacking prices up (like currently). However, most of the problems we are currently having are not lack of oil supply, but actually lack of refinery capacity - which is mostly some economic nonsense by feel-good environmental liberals with quack science used to "prove" their theories or "protect" species which may or may not be working to succumb all on their own, regardless of human interaction.
Anyway, the point is that there are solutions already around that would get implemented once the gas price peaks out. No, ethanol from corn and biodiesel from soybeans waste a lot of energy in order to weakly move us over to some sort of internally-produced oil base. Factually, ethanol can be created from any cellulose product, not just those which have high starch levels. The diesel engine was designed originally to run on peanut oil directly. So almost any oil can be used to run one, factually. Shift over to a canola-based agriculture (knock off those fat federal ag bail-outs and trade protections and we would quickly move over to viable production. Turn loose our genetic studies into making higher-oil producing crops and we would turn over to a diesel-run society - and away from oil problems - with less pollution and less cost.
So the problem of crude oil-based economies would disappear.
But please, take off the liberal weak-kneed sappiness from the logical and economic reality.
CommUnity of Minds : Working Together: "Rather than fighting the peak, perhaps we can work with it? Our quality of life, if not number of conveniences, might even improve in a low energy world. Examples came from local experiments in natural cob building; urban and rural permaculture properties; Cuban urban organic gardening; and experiments in local alternative currencies. Strong cases were made: through intelligently designed organic farming practices and community restructuring, healthier foods can be harvested, comparable with the yields of oil dependent industrial agriculture. Strengthened local economies can help us weather the storm of global instabilities and rebuild a sense of place and community.
The conference ended with suggestions of immediate, practical steps, which could be taken. David Holmgren recommended that everyone begin with a total audit of their household’s consumption of food, energy and water usage. Others talked about trading a car for a bicycle; insulating the attic; learning how to grow food; starting a community garden; learning natural building techniques. Richard Douthwaite stressed the importance of community involvement and creating bottom-up solutions."
Update: Cities are facing exodus to the suburbs, where people with sufficient funds are moving to raise their children. Commuting is the problem, but again solvable as above, where centralized transport could be achieved - or decentralized economy can be implemented, with Internet-based home-offices. All of this technology is already here - it just needs to be implemented. Suburbs also have far more resources than vertically-integrated cities. Larger families could supplement their food supply with small gardens as well as grid connected solar and wind-powered generators. Refuse not returned to the family garden as compost could be centrally collected and recycled - since without cheap oil, such recycling would become quite profitable. And believe me, it would be cheaper to raise more kids when they can be supported locally - despite the above link's insistence that population would decrease (factually, population decrease majorily has more to do with a rise of personal disposable income (and access to effective contraceptives). A lower personal income (meaning less access to cheap contraceptives) means increased population - as does the need for raising one's own food with cheaper labor.
Meanwhile, as Latins flood across our borders and Middle-Eastern/African Muslims flood into Europe, the Chinese are flooding into Russia. Practically, this means the merging of current Anglo-European rule with other ethnicities (as America has been doing for years). These new minorities have better work ethics than the decadent pale majorities they will be merging with. So the countries which survive these upcoming years will be far more diverse and tolerant of ethicities and intolerant of extremist intolerance of any brand or type.
Figure that the global population will still peak at 2050, regardless of Peak Oil. Figure that American ingenuity will solve the crunch problems facing or economy.
Meanwhile, drop off the fatalism and get real.