The Oil Drum

I don't even think you have to go that far. Most of the recent rural to urban migration in poor countries is really family members, that will, without a doubt, move back home to the family farm in the event of a crisis. It's not really that they are investing in social capital. They have transiently moved to where they can make better money. In the event of a famine, this tide will reverse, and the urban poor will quickly migrate back to the countryside.

Once back on the farm, they will quickly reintegrate with the village because they never really left in the first place.

Also, in the real event of a famine, the idea of mono cropping cereals for cash will be ditched quickly. These people may be poor, but they aren't so stupid they will accept death. The cereal crops they raise will be abandoned for integrated gardening just as quick as they can manage it. This will put further pressure on grain prices, but will allow much of the poor to live out a crisis. Most rural families who import food do so because it is relatively easier to grow a single crop, sell it and buy what you need than managing a complete garden, especially when several family members are earning money in the city and sending it home.

No, the 3rd world poor will quickly adapt during food scarcity. They are only a decade or two removed from it, and the knowledge hasn't been lost.

It's the first world non immigrant poor who will starve. That's where the crisis will be.

Apologies if I wasn't being clear - I am not claiming that urban areas can be self-sufficient in food, or that calorie crops produced on a larger scale are not essential - merely that, for example, those 18 days worth of calories can make the difference between starving to death and mere malnutrition - or between malnutrition and a barely adequate diet. My mention of staple vegetables was simply to observe that the idea that vegetables provide minimal calories is not always correct. Let's imagine a 200 square foot plot for a family of four, for example. Such a plot, intensively managed, could produce enough dense calories for, say four or five full days of additional survival, or more likely, 10 or 12 days of marginal survival. That's a big contribution to the yearly diet for a person suffering from malnutrition. Then add flavorings, nutritious greens, some leguminous protein crops a couple of chickens running around for eggs, fat and proteins, fed mostly on weeds, scraps and garden wastes. There are probably two full weeks of survival no one has to pay for (amortized over the course of the year) plus supplemental nutrition. Given that the majority of the world's poor spend 70% or more of their income on food, 2 weeks of not buying food is an enormous difference in their lives - think about how large a percentage of your income 2 weeks salary that can now be applied directly to future food purchases would (not a perfect analogy, I know).

Again, it isn't my claim that people can live on 100 or 150 square feet - far from it. But gardens in fairly small spaces can make a critical difference in diets, providing a margin for survival. Nor am I claiming that this will keep billions people who are being systematically starved alive - far from it. Merely that any analysis of the mitigating factors might wish to include the nutritional and caloric content of garden production.

It is also useful to think about the aggregate effects of such gardens - for example, Michael Hamm and Monique Baron have calculated that 3 million 200 square foot gardens in the state of New Jersey, *plus* existing farmland* would be sufficient to feed the state - if the gardens were planted into appropriately nutritious crops. That is, such a 200 square foot garden won't feed a person for a year, but the supplemental value does dramatically reduce the total amount of arable land required to feed a given region. Does this make sense? That is, gardens do not function as simply "supplemental, uncounted" calories - they produce some tiny percentage of needed calories, which added up on large enough scale, makes a huge dent in the practicalities of needed farmland.

There are number of fascinating analyses of this data in Koc, McRae et als _For Hunger Proof Cities_. But your larger point stands - no one is going to be producing all their food on a rooftop, and we will all need calorie crop production. Cuba kept importing rice, and Russia kept growing and importing wheat during the worst of their crises. But I think there's at least as great a tendency to underestimate the potential of small scale food production as there is to overestimate it.

Sharon

In a pinch people will be quick studies. I know crap about gardening but I know people who do and in a pinch I can count of them.

we could have community gardens on roofs, gardens on porches and in abandoned lots. parks could be converted.