World Bank economist Herman Daly points out the kinds of definitions of sustainability that he findsto be counterproductive. They include "sustainable development is development that sustains thehighest rate of economic growth without inflation." That's just business as usual, described a littledifferently, so that our present notion of growth will keep its course. Or: "Sustainability considers theexpanding needs of a growing world population, implying a steady and necessary growth." It impliesthat development will need to be continuous and steady, instead of requiring any leveling off to meet acarrying capacity. Formulations like these are inadequate, so Daly himself proposes three specificrules of sustainability to make sense in economic terms:1. Harvest renewable resources only at the speed at which they regenerate.2. Limit wastes to the assimilative capacity of local ecosystems.3. Require that part of the profit be put aside for investment in a renewable substitute resource.And for him, sustainable development does not follow from more free trade between production andconsumption ecosystems across global lines. For a nation to create a sustainable economy, it must stepback from the global economy. Sustainability requires a smaller scale bound in which to be tested. Itwill begin as an experiment, not as law. This is the remarkable potential of EXPO 2000. Imagined as asustainable community, it will be a model for the planet of what a sustainable settlement might looklike in our increasingly complicated world.
Examples of sustainability are not hard to cull from the history of world cultures. But most often theyare small scale social solutions that involve a small number of people who do little or no damage totheir surrounding habitat. And often there is no design or designer which guides the inhabitation ofthe place. But now the complex of human/nature interactions is more intricate and overlapping, andthe scale of change gets faster all the time. We cannot simply set up a benign situation and let aninnovative solution slowly evolve to meet ecological constraints. Design is necessary, but a very specialkind of design that does not claim to control more than it knows.We find hopeful, if distant, examples in works such as Bernard Rudofsky's Architecture withoutArchitects. Villages, cities, fortresses, and monasteries are presented from traditional cultures acrossthe globe. Buildings are arranged so that the flows of wind are channeled and harnessed, not blockedand diverted. It is clear that they have had the luxury of time: no one commissioned these structuresand demanded them built and ready for use in a year or two. Intervention was slow enough to be testedby the strength of natural forces and the sobering spirit of time. Still, the structures of less mechanisticcultures are those that have endured the longest, suggesting that sustainable building relies less on anabsolute coherent plan than on the cooperation between designers and end-users.