SAN FRANCISCO - The world marks annual World Environment Day on Sunday grappling with headaches caused by fast-growing cities.
The UN Environment Programme gave the following facts about cities:
* The world is becoming more urban. In 1950, fewer than one person in three lived in a town or city. Today, nearly half the world's population is urban and by 2030 the proportion will be more than 60 per cent.
* Fastest growth in the next 25 years will be in urban areas in developed nations with fewer than 500,000 people. In 2000, there were more than 400 cities with more than one million inhabitants.
* "Mega cities" -- urban areas with more than 10 million inhabitants -- include Tokyo/Yokohama, Mexico City, Seoul, New York, Sao Paulo, Mumbai, New Delhi and Los Angeles. In 1950, New York was the only city with more than 10 million people.
* In developed countries, 75 per cent of the population is urban, with lower percentages in poorer regions.
* Urbanisation in rich countries has largely coincided with economic growth, a trend not matched in poor regions. In Africa, more than 70 per cent of the urban population -- more than 160 million people -- lives in slums.
* At least one billion people, or one-sixth of humanity, live in slums and informal squatter settlements, mainly in Asia, Africa and Latin America. The figure could double by 2020.
* One target of the UN's millennium goals is to "significantly improve the lives of at least 100 million slum dwellers by the year 2020".
* Unsafe water, inadequate sanitation and air pollution are among threats in slums. Acute respiratory infections and diarrhoea are the biggest killers of children under five.
* Power generation, industry and transport, now mainly associated with towns and cities in the developed world, are responsible for most emissions of carbon dioxide, the main greenhouse gas blamed for global warming.
* Climate change could swamp low-lying coastal towns and cities as a result of a rise in the sea level, and cause more frequent and severe storms. About 40 per cent of the world's population lives within 60 km (40 miles) of the coast.
* Municipalities can spend as much as 30 per cent of their budget on waste disposal, mostly on transport.
* An average North American city with a population of 650,000 requires 30,000 sq km (11,580 sq mile) of land to service its needs. By contrast, a similar sized but less affluent city in India requires just 2,800 sq km.
* A city of 10 million people -- such as Manila, Cairo or Rio de Janeiro -- imports at least 6,000 tonnes of food every day.
* Managed well, cities can support growing populations. Examples include tree plantings and setting aside green spaces, the use of so-called "grey water" to flush toilets, low-polluting vehicles and efficient public transport systems, low-energy lighting and waste recycling.
REUTERS NEWS SERVICE
