Over the next two decades, the world will see a burst of urban expansion at a speed and on a scale never before witnessed in human history. When you hear about the coming urban age, it's really a story about rising Asia and the two countries that will define this new era of the megacity: China and India. Half of Asia will become urbanized, and nearly a billion people will shift from countryside to cityscape.

Trillions of dollars will need to be spent on roads, trains, power plants, water systems, and social services. And it's going to happen in less than half the time that it took the West. China and India will account for two-fifths of the world's urban growth, but they are pursuing wildly different strategies for managing this shift. Beijing's approach is systematic: The government has invested ahead, allocated land, plotted out transportation networks, and given its cities the freedom to raise capital. New Delhi, meanwhile, hasn't done enough to prepare. So while China has embraced a future of office parks and high-speed rail, India is just waking up to its new urban reality.

The megacity will be home to China's and India’s growing middle classes--creating consumer markets larger than to-day’s Japan and Spain, respectively. In China, the number of urban middle-class households will quintuple; in India it will grow nearly fourfold. India's wealthiest urban households--those earning more than 1 million rupees a year (about $22,000)--could number 11 million, more than the total number of households in Australia today. In both countries, the wealth gap between rural and urban areas will grow with urbanization. Urban GDP per capita will exceed rural GDP by 3.5 times in China and more than five times in India.

Urban growth will come with a high price tag--a whopping $35-$40 trillion in China and $2.2 trillion in India over the coming two decades. In addition to all the building and public infrastructure, China and India will need to invest heavily in delivering services--everything from education to health care to social security. As China's over-65 population more than doubles and migrants flood its cities, government spending on health care will struggle to keep up, rising from 19 percent to 21 percent of GDP. Even with China’s massive economic growth, paying the bill won’t be easy. Many of China’s largest cities are self-sufficient, but other smaller and newer areas are already running deficits. India’s urban spending, meanwhile, is already very low by international standards.

> Read the full article "Megacities" at ForeignPolicy.com.

Changing How We Reach People
The urbanization of the world--a great move of people toward cities--is not limited to Asia. One hundred years ago, 80% of the world's population lived in rural areas, and just 20% lived in cities. By the middle of this century that number will be reversed--80% will live in urban areas and just 20% will live rurally. In the United States our city suburbs are considered part of the urban landscape--and it is changing how we reach people and share the Gospel as the shape of our neighborhoods change.

> Wikipedia: What is a megacity?

> National Geographic explores megacities

> Megacities feature from PBS News Hour