Cities and Sustainability
After spending tens of thousands of years living in small settlements, humans have entered an urban stage of evolution. That concentration of people gives rise to some of the world's greatest problems, such as air and water pollution, poverty-stricken slums and epidemics of violence and illness.
In less than a human lifespan, the face of Earth has been transformed. In 1950, only 29% of people lived in cities. Today that figure is 50.5% and is expected to reach 70% by 2050. At the end of the 20th century, humans lived in enlarging cities with populations in the millions; their carbon dioxide emissions are greater than the capacity of all the world’s forests to process the gas. Cities consumed two-thirds of the total energy used and emitted more than 70% of the energy-related carbon dioxide emissions. City states are depleting these resources at an alarming rate – fish stocks are depleted; soils are depleted, washed or blown away; fresh water supplies are marginal, depleted or contaminated; the air is polluted and ozone depletion combined with global warming from increased greenhouse gases threatens progressive and erratic climate changes. Climate changes threaten agriculture, as we know it.
William Rees, an economist at the University of British Columbia takes and ecological approach to economics. He is concerned that cities are growing too large to be sustainable. Cities are centers of consumption and depend on the surrounding environment to supply energy, food and to accept and disperse waste. Rees has measured the ecological footprint of cities and his results are not encouraging. One city person requires at least five square hectares of high-quality land to support him or her. The 500,000 people living in the city of Vancouver on 11,400 hectares of land actually require the output of 2.3 million hectares of land. The real capital is not money but air, water, food and other resources.
Some scientists have imagined major disruptions of city-states with civil disobedience and armed conflicts arising from the competition for scarce resources. Solutions are available but are improbable, given our basic tendencies. A sane, rational city-state would limit its growth; limit its pollution and progress toward food, water and air sustainability. If all long-distance supplies were blocked could the citizens of a city continue to live comfortable, healthy lives? One criterion of a sane city would be self-sufficiency. To make cities more livable and less polluted, car use would be reduced to less than half of current levels and car-free zones would restore healthier living conditions for many citizens.
For many urban dwellers, advanced electronic networking would reduce the need for commuting and long-distance travel would be considered a luxury and rationed. The need to transport food and goods would be reduced by increased local production. The transportation of goods would be streamlined into centrally controlled supply lines that achieve maximal efficiency. We could advance toward intelligent distribution systems such as large pneumatic or electromagnetic tubes that send containers between city centers at high speed with minimal pollution. It is absurd to have goods distributed in trucks, in traffic, chaotically with no cost effective distribution plan. Food can be grown and processed within a city by returning some of the land area to market gardens and intensive greenhouse technology.
Cities are governed by elected politicians who have a range of abilities and limited knowledge of the environment and Human Nature. Urban governments exist to provide services to citizens. Usually, planning is motivated to increase populations by expanding developments that are destructive of the surrounding environments. Cities are cancers that overwhelm their host. In 2016 the city of Vancouver has a “housing crisis.” The demand for living space has exceeded supply, the price of real estate is rising and educated young people entering the workforce cannot afford to live in the city. Planners are suggesting that green space around the city should be developed to provide rental housing. No one suggests that there must be no further city growth and increasing the population is not desirable nor feasible.
Cities are so enmeshed in their surrounding regions that it no longer makes sense for them to be the sole focus of sustainable planning. Satellite images reveal patchworks of communities, industrial zones, farmland and natural ecosystems threaded by a web of transport links. For people and nature to thrive, the arrangement of land systems and water across the urban region must be managed holistically. Essential are experts in ecosystem and landscape ecology, water quantity and quality, agricultural soil quality and productivity, economics, transportation infrastructure engineering and community development.