Paging Thomas Malthus: Your nightmare finally has arrived.
Malthus, a British economist, famously predicted in 1798 that population growth eventually would outpace food production, resulting in mass starvation. Ever since his time, the phrase "Malthusian nightmare" has been applied to dystopian scenarios predicated on demographic doom and gloom.
For the most part, these predictions--including Malthus's--have turned out to be overly pessimistic. But now, the spectacular growth of Third World megacities holds the depressing possibility that Malthus may turn out to be right after all.
That doesn't necessarily mean mass starvation; the advent of advanced agricultural technologies may prevent that nightmare scenario from ever panning out. But the world's new megacities offer plenty of food for dark Malthusian thoughts.
As urbanization continues apace--60% of the world's people will be city dwellers by 2030--billions of people will be living in vast slums in the developing world, facing a long list of urban ills on which starvation may be just another bullet point.
In 1900, the world's largest city was London, which did not even qualify as a megacity. (The threshold for that dubious distinction is 10 million people; London had 6.5 million that year.) Every city in the top 10 that year was in Europe or America, with one exception: Tokyo, then the world's seventh-largest city, with 1.5 million people.
Today, Greater Tokyo is the world's largest city, with a population of 35.2 million. In 2015, it will retain the pole position with 35.5 million, according to United Nations population projections. But Tokyo's growth rate is slowing.
The demographic future belongs to cities like Mumbai, Shanghai and Dhaka.
Even as the world's overall population eventually stabilizes somewhere between 9 and 10 billion, the megacities will continue their relentless expansion, as the rural poor move to town and become the urban poor.
They will keep coming despite the daunting problems that await them in the cities: crime, pollution, crumbling infrastructure, lack of housing. Undeterred, they will pack themselves into crowded shanty towns that lack running water or sewer service, and--amazingly--they will consider themselves better off than if they had stayed in the sticks.
When America tries to police this brave new world, it will run into trouble. Picture Baghdad's Sadr City slum, multiplied a hundred-fold and metastasizing all around the globe.
That's the bad news. The good news, at least for optimists, is that the developed world already has come through the urbanization wringer and survived to tell the tale. The United States had three of the world's most populous cities in 1900--New York, Chicago and Philadelphia.
The U.S. was 50% urbanized by 1920; nowadays, most Americans live in urban areas, and live quite comfortably. The same is true for the other nations that had top 10 cities at the turn of the 20th century. America's two current megacities, New York and Los Angeles, face their share of challenges, but few of these could reasonably be described as apocalyptic.
The World's Ten Largest Cities In 1900
Rank Urban Area Population 1 London 6.5 million 2 New York 4.2 million 3 Paris 3.3 million 4 Berlin 2.7 million 5 Chicago 1.7 million 6 Vienna 1.7 million 7 Tokyo 1.5 million 8 St. Petersburg 1.4 million 9 Manchester 1.4 million 10 Philadelphia 1.4 million
Source: Four Thousand Years of Urban Growth: An Historical Census by Tertius Chandler.
When London's population multiplied exponentially during the Industrial Revolution, Malthus made some calculations and foresaw catastrophe. Similarly, Karl Marx predicted that London's teeming slums and Manchester's dark, satanic mills would breed revolution.
Instead, they sped the pace of evolution, as British society adapted to the changes and ameliorated the problems. The implications for the Third World are clear: Urbanization on an epic scale is inevitably traumatic, but it need not end in complete disaster.
Still, there is no guarantee that the pessimists' dystopian visions will not come to pass. The future will be determined in such cities as Lagos, a place that would have made Malthus shudder. In 1950, less than 300,000 people lived in Lagos. Now, a staggering 10.9 million people do.
That's bad enough, but the U.N. projects that Lagos will host 16.1 million people by 2015. That's 5 million new residents in less than a decade, added to a city already crumbling into chaos under the strain of its current population.
Can such a city survive, let alone thrive? It won't be long before we all find out.