The first cities we know of were located in Mesopotamia, such as Eridu, Uruk, and Ur, and in Egypt along the Nile, the Indus Valley Civilization, and China. Before this time it was rare for settlements to reach significant size, although there were exceptions such as Jericho, Çatalhöyük and Mehrgarh. It is estimated that ancient Rome had a population of about a million people by the end of the first century BC, after growing continually during the 3rd, 2nd, and 1st centuries BC. It is generally considered the largest city before 19th century London. Alexandria’s population was also close to Rome’s at around the same time. Historians estimate a total population close to a million based on a census dated from 32 CE that counted 180,000 adult male citizens in Alexandria. Similar administrative, commercial, industrial and ceremonial centres emerged in other areas, most notably Baghdad, which to some urban historians later became the first city to exceed a population of one million by the 8th century instead of Rome.
Viva La Revolucion!
The industrial revolution from the late 18th century onward led to massive urbanization and the rise of new great cities, first in Europe and then in other regions, as new opportunities brought huge numbers of migrants from rural communities into urban areas. In the United States from 1860 to 1910, the invention of railroads reduced transportation costs, and large manufacturing centres began to emerge, thus allowing migration from rural to city areas possible. However, cities during those periods of time were deadly places to live in, due to health problems resulting from contaminated water, air and disease. In 1950, 30 percent of the world’s population lived in cities. In 2000 this proportion grew to 47 percent, and it is predicted to rise to 60 percent by 2030. Urbanites earn more income than rural residents, due to the fact that city living facilitates learning, innovation and specialisation. Richer workers can afford to purchase more energy-intensive durables such as cars and household appliances.
As a consequence, urban populations consume 75 per cent of the world’s natural resources while simultaneously producing 75 per cent of the planet’s waste. Nearly 200 years ago, London was the only city in the world with more than one million people. Today, across the globe, there are more than 400 cities at least that size. Modern cities have indeed become so large that they actually create their own micro-climates. This is due to the large clustering of hard surfaces that heat up in sunlight and that channel rainwater into underground ducts. As a result, city weather is often windier and cloudier than the weather in the surrounding countryside. Conversely, because these effects make cities warmer than the surrounding area they also cause significant knock-on environmental effects such as global warming.
Deforestation and Dustbowls
According to the UN’s Millennium Ecosystem Assessment report, 47% of the Earth’s land surface was covered with forests prior to the modern industrial era; today the planet is left with only 10% of that. Every day, thousands of rural poor in India move to big cities where there are few environmental policies in place. Though they have come in search of a better life, many eventually end up living in slums, with no access to safe water or sanitation facilities. Yet, they add to the increasing demands of the city population for food and energy. According to UN population surveys, India is likely to have 700 million rural poor moving to its cities by 2050 if the current trend is not reversed in the next few years. With 45,000 plant and nearly 90,000 animal species, India is considered one of the world’s most mega-diverse countries. Experts say the continued growth in its urban population could lead to enormous loss of biodiversity.
In China, a human population of 1.3 billion and a livestock population of just over 400 million are weighing heavily on the land. Huge flocks of sheep and goats in the northwest are stripping the land of its protective vegetation, creating a dust bowl on a scale not seen before. Northwestern China is on the verge of a massive ecological meltdown. Desert expansion has accelerated with each successive decade since 1950. China’s Environmental Protection Agency reports that the Gobi Desert expanded by 52,400 sq km (20,240 square miles) from 1994 to 1999. With the advancing Gobi now within 150 miles of Beijing, China’s leaders are beginning to sense the gravity of the situation.
The strong winds of late winter and early spring can remove literally millions of tons of topsoil in a single day – soil which can take centuries to replace. For the outside world, it is these dust storms that draw attention to the deserts that are forming in China. On 12 April 2002, for instance, South Korea was engulfed by a huge dust storm from China that left people in Seoul literally gasping for breath. Schools were closed, airline flights were cancelled, and clinics were overrun with patients having difficulty breathing. Koreans have come to dread the arrival of what they now call “the fifth season” – the dust storms of late winter and early spring. Japan also suffers from dust storms originating in China. Although not as directly exposed as Koreans are, the Japanese complain about the dust and the brown rain that streaks their windshields and windows.
Urban Solutions or Urban Myths?
However some argue that urban growth offers some beneficial trends. For instance, since urbanites have fewer children than rural households, cities generally have slower aggregate population growth than rural nations. Also since cities are often deemed hotbeds of innovation, urban nations are more likely to develop green technologies such as hybrid vehicles and alternative fuel sources.
Technological advance can certainly help to further reduce greenhouse gas emissions per dollar of national income. But if technology is to come to the rescue, economic factors– including countries, firms and individuals – must have sufficiently strong incentives to reduce carbon dioxide and other greenhouse gas emissions.
On 15 May 2005, Mayors from around the globe took the historic step of signing the Urban Environmental Accords in the rotunda of San Francisco City Hall in recognition of United Nations World Environment Day 2005. Delegates from 50 of the largest industrialised cities on the planet drew up a charter that they claimed to be a new and bold course toward urban environmental sustainability.
Let’s hope these so-called historic accords and protocols result in producing more than just additional bureaucratic ‘hot air’.