Cities hold the key to sustainable living for the world's rising population - but: cities are concentrated areas of resource consumption, and so cannot be self-sustaining
- but: a city has to be seen as part of its environment, and that whole environment can be sustainable
- because: cities consume water from the surrounding water catchment, not just from within themselves
- but: the growth of cities has created huge environmental and social problems
- Solution: reduce the use of cars to a minimum
- Effect: increase the use of public transport
- but: planners have designed cities around cars rather than people
- because: they idealised mobility and freedom
- because: e.g. cities in the U.S. were based on Frank Lloyd Wright's vision of suburban homesteads connected by highways
- Solution: reduce, re-use, recycle and re-think as much as possible
- because: many cities are made up of socially deprived neighbourhoods
- Solution: cities with multiple centres allow people to live close to their work in high-rise blocks that are also near public transport hubs
- Effect: the density of high-rises can create an heat-island effect
- Solution: green roofs, supporting plants, can help control temperatures (Wikipedia contributors (2009) )
- Solution: planting trees along the streets can help reduce air temperatures
- Solution: buildings can be designed to reduce direct sunlight through windows, increase ventilation, and cut energy absorption by painting external walls white
- because: dense cities heat the air around them
- because: they are organized into residential, commercial, and industrial zones
- because: cities expel clouds of greenhouse gases, tonnes of solid waste, and rivers of toxic effluent
- because: the high volume of pollutants over-loads the systems that dispose of them
- because: many cities already have eco-projects
- because: e.g. the eco-city of Dongtan, near Shanghai, is the first ever built from scratch (The Economist (2006) )
- because: e.g. wind turbines and solar cells generate up to 85% of the electricity used in the building that housed the Melbourne city council
- because: e.g. garbage trucks in San Diego run on methane extracted from the landfills they deliver to
- because: e.g. Germany's new parliament building in Berlin uses carbon-neutral vegetable oil to cut its CO2 emissions by 94%
- because: it's possible for cities to partly feed themselves
- because: cities can have vertical farms (Wikipedia contributors (2008) )
- but: vertical farms are only in the design stage, no real ones have been built, so there is no evidence that they are practical (Feldman (2007) Section: Final interview question)
- because: the size of a city creates economies of scale for energy generation, recycling, and public transport (Pearce (2006) )
References
Feldman, Amy (2007-07-11). "Skyscraper Farms", Popular Science. (http://www.popsci.com/environment/article/2007-07/skyscraper-farms)
Pearce, F. (2006). "Ecopolis now." New Scientist, Vol. 190, Issue 2556, p.8, June 17.
The Economist, Sept. 23, 2006. "Visions of ecopolis." Vol. 380, Issue 8496, p. 20-23.
Wikipedia contributors, 'Green roof', Wikipedia, The Free Encyclopedia, 17 January 2009, 17:31 UTC, (accessed 20 January 2009). (http://en.wikipedia.org/wiki/Green_roof)
Wikipedia contributors, 'Vertical farming', Wikipedia, The Free Encyclopedia, 19 December 2008, 01:54 UTC, (accessed 20 January 2009). (http://en.wikipedia.org/wiki/Vertical_farm)