The century of the city: top eight new megacities by 2025

A brilliant new feature by the folks at Nature explains why this century is for the city.

Called "The Century of the City," the feature outlines what's going on around the world -- and how it impacts the work of scientists and others.

The feature is full of wonderful infographics, but also contains some starting facts.

Among them:

• The United States is one of the few developed countries where cities continue to grow. Its urban population is predicted to increase by 15 percent to reach 308 million in 2025.
• Most urban growth in the U.S. isn't happening in big metro areas -- though New York City is predicted to reach 20.1 million people by 2025 -- but in smaller cities with less than a million people.
• Europe is stagnating. It's predicted to grow incrementally as a whole, but shrinking populations in the East balance out some growth in the West.
• Latin and South America are the most urban in the world, with 80 percent of the population in cities.
• Africa is the least urban in the world, with 40 percent of the population in cities. But its cities are among the fastest growing in the world.
• Asia leads the charge into urban living, and as a continent, its cities are growing faster than any other's, fueled by growth in China, India and Bangladesh.

But if you're into rankings, most interesting is the Top 10 list of megacities now -- and the cities that will join them in 2025.

According to the report, the most populous megacities now are:

1. Tokyo, Japan (36.67 million people)
2. Delhi, India (22.16 million)
3. Sao Paolo, Brazil (20.26 million)
4. Mumbai, India (20.04 million)
5. Mexico City (19.46 million)
6. New York City-Newark (19.43 million)
7. Shanghai, China (16.58 million)
8. Calcutta, India (15.55 million)
9. Dhaka, Bangladesh (14.65 million)
10. Karachi, Pakistan (13.13 million)

Please note that the figures go beyond official city limits and include the region that surrounds them.

To that list, add these predictions for 2025 (which I'll remind you is just 15 years from now):

1. Kinshasa, Congo (15.04 million)
2. Shenzhen, China (11.15 million)
3. Chongqing, China (11.07 million)
4. Guangzhou, China (10.96 million)
5. Jakarta, Indonesia  (10.85 million)
6. Bogota, Colombia (10.54 million)
7. Lima, Peru (10.53 million)
8. Lahore, Pakistan (10.31 million)

Note the nations where these cities are located. (You might argue that it's time to start teaching American children Chinese.)

Nature argues that while cities are cause of some of the world's most glaring problems, they're also home of the most innovative scientific breakthroughs -- and better still, urban scientists are beginning to use their labs to directly address urban problems.

Nature writes:

The threats to cities and the opportunities they present are attracting increasing attention from researchers in many areas. Synthetic biologists, for example, are exploring molecules that could clad skyscrapers and trap carbon dioxide. Scientists have a responsibility to supply many more advances of that nature to ensure the viability of humans as an urban species.

In fact, global climate change is one topic that has urban scientists concerned, largely because it's the cities they call home that perpetrate it. They consume far more resources than their share of the world's population permits, and worse, they emit even more carbon emissions.

Can we achieve a truly sustainable city -- one that's not only sustainable within itself, but in context of the world around it? Lots of smart folks are certainly trying.

I urge you to read their entire report -- then return to SmartPlanet and discover what scientists and others are doing to solve these problems.

This post was originally published on Smartplanet.com