Creating Sustainable Cities

The global environmental impact of urban resource use could well become the dominant feature of the human presence on earth and, given the reality of ever larger numbers of cities, one of humanity’s greatest challenges for the new millennium.

Only in countries that are ‘fully’ developed, such as the UK or USA, where rural lifestyles have been effectively urbanised, are levels of consumption in urban and rural areas broadly similar.

The growth of modern urban economies, then, usually means two things: increased demands on the natural capital supplying cities, as well as increased discharges of wastes into the local and global environment. The global environmental impact of urban resource use is becoming a critical issue in the future of urbanisation and the dominant feature of the human presence on earth. As humanity urbanises, it also changes its very relationship to its host planet: global urbanisation has greatly increased humanity’s use of natural resources. This can be witnessed today in developing countries, where urban people typically have much higher standards of living than rural dwellers, depending on massively increased throughput of fossil fuels, metals, meat and manufactured products.

a planet that is urbanising, industrialising and globalising—at least for the time being.

Ten main factors contribute to urban growth:

• national economic development

• urban accumulation of political and financial power

• import substitution

• economic globalisation

• access to global food resources

• technological development

• cheap energy supplies

• expansion of urban-centred transport systems

• migration from rural areas

• reproduction of urban populations

is clear that urbanisation is driven above all else by economic factors, and in discussing sustainable development we have to deal with the reality

The global economy has grown many times over in the last 50 years and it is becoming ever more integrated. “In 1950, most of the world’s workforce was employed in agriculture; by 1990 most worked in services.”

The most pronounced difference between ancient Rome and much larger modern cities such as London is their vast use of energy. Contemporary London, with 7 million people, uses around 20 million tonnes of oil equivalent per year, or two supertankers a week, discharging some 60 million tonnes of CO2 into the atmosphere.13 The critical issue is whether, and how, these figures can be reduced in the process of assuring greater sustainability. Can modern cities reduce their impact on the biosphere by processes of enlightened self-regulation and self-limitation

The cause of the exhaustion of the soil, is sought in the customs and habits of the towns people, i.e., in the construction of water closets, which do not admit of a collection and preservation of the liquid and solid excrement. They do not return in Britain to the fields, but are carried by the rivers into the sea. The equilibrium in the fertility of the soil is destroyed by this incessant removal of phosphates and can only be restored by an equivalent supply . . . If it was possible to bring back to the fields of Scotland and England all those phosphates which have been carried to the sea in the last 50 years, the crops would increase to double the quantity of former years.”

Above all else, it requires the management of soil fertility and crops for the assured supply of foodstuffs to urban populations over sustained periods of time.

be viable in the long term, presupposes a clear understanding of conditions for sustainable human interactions with nature—an understanding that was not required before urbanisation started.