Stewart Brand
A cynic might agree wholeheartedly with Stewart Brand’s assessment that slums can provide a glimpse into the future of city life. Although there is likely some truth to the fact that as you pack people tighter and give them less of everything they will have a smaller environmental footprint, it seems quite ridiculous to believe that there is a significant portion of the population in developed cities that would accept such living conditions.
Although economic realities force many people in places such as NYC to live in smaller spaces than they might otherwise wish (excluding the small portion who seem to love tiny apartments), the universal goal seems to be saving up to be able to afford larger, more luxurious surroundings. Brand’s article even points out that to make city living possible, “subsidised housing could bring down the high cost of city centre living” enough to prevent families from fleeing to more realistically priced suburbs. Why are subsidies required to make this reality possible, if city living is so efficient? Because people desire space, and most don’t want to live in a space equivalent to a typical suburban walk in closet. When you pack people into less space than they really want to have, space becomes a valuable commodity, and the price skyrockets.
The quoted claims from Science that a future “farm on one city block [that] could feed 50,000 people with vegetables, fruit, eggs, and meat” seem likely to be greatly exaggerated. With the size of a standard city block between 5-10 acres, and the ability to feed 10 people from 1 acre based on the amount of energy falling from the sun, this translates to food for 100 people. With a greenhouse that is 20 times more efficient than growing in open air (the maximum gain cited in the Science article), make that 2000 people. Hoping for a build out of new hydro, solar, or geothermal plants to power this hydroponic and artificial light energy sink seems like wishful thinking. The cost and energy used in building such a 30 story farm will have a very hard time beating (not-quite-as) local produce farmed in natural sunlight and trucked in from the surrounding countryside. Even assuming that the 50,000 people fed per block number is correct, feeding its 1.7 million residents would require 32 blocks of Manhattan to be converted to farming. A more realistic number of 10,000 requires 160 blocks, or nearly 2.5% of the land in the borough.
In short, although it may be desirable to try to convince people to emulate some of the qualities of slum life (recycling, reusing) it seems unlikely that most will be willing to give up much of the convenience and luxury that sap the efficiency that comes from living in cities. Environmental planning that relies on subsistence and sacrifice (the main virtues of the slum living held up as a teaching model) as its main method of energy efficiency seems like a dark plan for the future.