Cities produce waste, a lot of waste. At the same time the production of consumer goods is at such a level that we are rapidly approaching the point where we have run out of basic materials. Already some rare materials like indium (used for LCD screens), tantalum (used in cellphones and microchips) or antimony (used in drugs) are becoming exhausted and the world supply left will last us not more than a generation or even less. But even the supply of normal, everyday materials like zinc, lead, tin or silver is becoming critical in the near future. If consumption and disposal of these materials goes on the way it does now, we will be out of supply within 10 to 20 years time. Of course these materials are not really gone, they are merely hidden inside the products we use, but also - and more so - inside this huge amount of waste we produce. So it seems smart to distract these rare materials from the waste, and to recycle and reuse them in new products.
In her book 'The Economy of Cities' (1969) Jane Jacobs predicts that the cities will become the mines of the future. Since this mining of materials is best done close to the point of production (of waste) she even predicts great economical advantages for big cities.
"In the highly developed economies of the future, it is probable that cities will become huge, rich and diverse mines of raw materials. ... The largest, most prosperous cities will be the richest, the most easily worked, and the most inexhaustible mines. Cities that take the lead in reclaiming their own wastes will have high rates of related development work."
Of course mining pure materials from waste is not always easy and may only be done at high costs. But this, according to Jacobs, is no problem at all. On the contrary, it may result in economical advantage. "In the past, when acute city practical problems have been solved, the solutions have not been an economic burden upon these societies. On the contrary, solutions have increased true economic abundance, true wealth. .. All the wealth extracted from recycled wastes, plus pure air and pure water, will represent increases in true abundance."
Since the publication of Jane Jacobs book, this recycling has indeed become an industry of its own, but we certainly have not yet reached the point Jacobs predicted. Currently, cities in developed countries still burn more waste than they mine, and most recycling processes in fact downgrade the materials that are recycled. It is only in so-called underdeveloped countries, in megacities like Cairo, Delhi and Lagos, that people - always from the lowest of classes or castes - really work in these 'mines of the future'. And although this informal industry is part of the city economy, it does not seem to lead to the ‘true abundance’ Jacobs predicted. This however may be only a transitory phase. What Jacobs was rallying for was to really invest in this mining industry and to innovate new and efficient ways of subtraction. Cities that do this first, may find that they not only solved a serious environmental problem, but also that they will be at the forefront of a new industry, and thus may create a sustainable economic future for themselves.
Jane Jacobs, The Economy of Cities, 1969