On a teeming street in Mumbai's Dharavi slum, amid a colorful swirl of sweet lime carts and red-clay pottery, Pastor Bala Singh brings an assortment of buckets to retrieve his daily ration of water. The indoor spigot he uses provides water only three hours a day. It is the only source for the six small homes on his street, and each family has 30 minutes to fill its containers.
Pastor Singh is not complaining, though. Things are greatly improved from when he first immigrated to Dharavi -- the most crowded part of one the world's most crowded cities. "The roads were muddy," he says from his second-floor office, above the popping sizzle of a man welding, sans protective gear, downstairs. "Now they put down bricks." Singh ministers to a small congregation that meets above the church-sponsored kindergarten where his wife has taught for 17 years. Though relatives have begged him to come home to Tamil Nadu, 700 miles east, he has no plans to leave.
"Three times I tried to go back to my native place," the pastor says, explaining that there were no jobs there. "I don't want to live here ... but God's plan is different."
Singh's migration to the city, a combination of divine impulsion and the simple need to work, is part of what could be called an epic trend affecting billions of people worldwide. Sometime in 2007, for the first time in human history, more people began to live within the cacophonous swirl of cities than in rural hamlets or on countryside farms.
It's a fundamental shift that may be altering the very fabric of human life, from the intimate, intricate structures of individual families to the massive, far-flung infrastructures of human civilizations. In 1950, fewer than 30 percent of the world's 2.5 billion inhabitants lived in urban regions. By 2050, almost 70 percent of the world's estimated 10 billion inhabitants -- or more than the number of people living today -- will be part of massive urban networks, according to the Population Division of the United Nations' Department of Economic and Social Affairs.
These staggering statistical trends are driving the evolution of the "megacity," defined as an urban agglomeration of more than 10 million people. Sixty years ago there were only two: New York/Newark and Tokyo. Today there are 22 such megacities -- the majority in the developing countries of Asia, Africa, and Latin America -- and by 2025 there will probably be 30 or more.
Consider just India. Though the country is still largely one of villagers -- about 70 percent of India's 1.2 billion inhabitants live in rural areas -- immigration and internal migrations have transformed it into a country with 25 of the 100 fastest-growing cities worldwide. Two of them, Mumbai (Bombay) and Delhi, already rank among the top five most populous urban areas.
In the "developed" countries of the West, this trend had been building since the Industrial Revolution, which sparked, relatively quickly, the exponential growth of cities seen today. The quest for "efficiency" and the corresponding divisions of labor generated technological innovations that obliterated the need for farm laborers and local artisans. This drove populations from the country to the city over time and transformed the plow and the hoe into mere tools for backyard gardeners.