Issue 54: Mega Cities Of Tomorrow

Issue 54
September/October – 2000
Story Title: Mega Cities Of Tomorrow

These are the mega cities of more than 10 million people, which have developed since 1950 (Source FAO-SOFA). In 15 years another three mega cities are expected to develop.

GEOFF WILSON reports there are 800 million people practising urban agriculture, and that inorganic and organic hydroponic technologies will play an increasing role in feeding the world’s poorest people, as well as the mega cities of tomorrow.

Worldwide, it is estimated that 800 million people are engaged in urban agriculture, which is playing an important role in feeding many of the world’s cities. This is the observation made by Urban Agriculture magazine, using 1990s data from the United Nations Development Program (UNDP), and from the UN Food and Agriculture Organisation (FAO).

According to the magazine, which launched in the Netherlands in June, urban agriculture can be expected to spread rapidly as urbanisation increases. The magazine predicts that by 2015, some 26 cities of the world can be expected to each have populations of more than 10 million, and their food needs will focus on urban agriculture that includes organic waste management. What the magazine did not say, but no doubt will in future issues, is that both inorganic and organic hydroponics will be important urban agriculture technologies to grow food in relatively small urban spaces, and offer greater urban food security.

The world’s poorer countries contain the majority of the 800 million people (7.5% of the world’s population), which are currently practising some form of urban agriculture. But this is changing as better waste management for affluent cities is required to overcome massive problems of pollution.

In 1988, when the UN agencies first began paying serious attention to urban expansion problems, only about 25% of the developing world’s absolute poor were living in urban areas. The World Resource Institute estimates that this year, around 56% of the world’s absolute poor are urban-based. Across all nations, poor and rich, FAO estimate that 2005 will be the year when urban area populations will surpass rural area populations. Food security requirements of the so-called conurbations, or mega-cities, some of which can be called ‘rich cities’, will then require close integration with enlightened waste management.

In mid 1999, the world’s population reached six billion. So, five years hence, some three billion people will live in cities, most of them in the largest 26 cities (see map).

As can be seen from Table 1, the pace of population growth has accelerated during the last 200 years. Table 1 gives a progressive total for billion people increases. The opportunity for urban agriculture in its many forms is, therefore, potentially vast.

Table 1
Year Population
1804 1 billion
1927 2 billion
1960 3 billion
1974 4 billion
1987 5 billion
1999 6 billion

In my view, future urban agriculture will be based on space-saving, water-efficient food production systems that use both inorganic and organic hydroponics. I say ‘based’ advisedly. Hydroponics can become ‘aquaponics’, or the production of fish, crustaceans and molluscs integrated with the hydroponic culture of plants. It can also be integrated with vermiculture, and the urban husbandry of certain small animals. This is where the high technology future of urban agriculture is headed.

A visit to Singapore’s magnificent agrotechnology parks gives a glimpse of the future for urban agriculture, where innovative organic and inorganic hydroponics have succeeded on the last vestiges of urban land (about 1,500 hectares) on Singapore Island. Other world cities still have urban and peri-urban land, or urban rooftops, that can be used for efficient food production, which will minimise harmful greenhouse gas emissions in two ways – organic wastes will be diverted from harmful methane-producing landfill, and petroleum-based transport energy will be reduced.

Growing food close to where it is needed by urban populations is a practice that makes great economic and environmental sense. The irony is that the 800 million or so people now practising urban agriculture are doing so for survival. Yet they are showing the way ahead for developed nations, and the mega cities of tomorrow.

Geoff Wilson is a Brisbane-based journalist and Executive Officer of The Urban Agriculture Network – Western Pacific Office.