Every day, Asia's cities expand by about 120,000 people, a level of urbanization unprecedented in human history. For many, this conjures up visions of an apocalyptic urban nightmare in which Asia's population will increasingly inhabit a twilight world of teeming, filthy, polluted streets.
However, the reality could be a whole lot rosier, for both Asia's urban poor and the environment.
Many of today's Asian cities already have populations exceeding those of some medium sized countries and are 10 times larger than cities in Europe at comparable levels of development. By 2015, half of the world's 22 megacities of more than 10 million people will be in Asia.
In addition, the region is home to vast, growing "mega regions," such as that stretching from Tokyo to Osaka, Kyoto, Kobe and Nagoya that will by 2015 accommodate about 60 million people. The Hong Kong-Guangzhou-Shenzhen region will by the same year be home to double that number.
Over the next 20 years, Asia's cities will be expected to accommodate at least 1.2 billion more people. The new urban dwellers are already on the way from the farm or have been born in the cities. There is nothing that can be done to stop this urbanization process, since this generation will need jobs and services. They won't find these in the countryside.
In many ways, these urban pressures in Asia are comparable to those faced in developed countries around the last decade of the 19th century. The influx then to the cities culminated in a situation now in which most of the urban areas of the developed world contain more than 90 percent of the population.
Back in the 1890s, the life expectancy for a male worker in a city like Manchester, England, was a mere 19. At least with all our present-day medical advances, the average male life expectancy today in a country like Bangladesh is three times more.
Likewise, Charleston, S.C., in the same era saw 323 children dying within a year of birth per 1,000 live births. Even in Asia's worst slums, the average infant mortality is now one-third of this rate.
Yes, the cities then were difficult places. But just as they do now, they also offered a wealth of opportunities.
Given a choice between stagnant rural poverty and promising city squalor, history has shown that people will always choose the latter.
If you live in an urban slum in Asia you can still go to the air-conditioned mall. And there is a health clinic on the next block, even if it is a pale shadow of the facilities available to the rich.
However, new systems are needed to assimilate the large influxes of people projected. Basic needs such as water, sanitation and housing are already stretched, with the poor usually the first to lose out.
Investing in required infrastructure is not just a matter of money, something that many Asian economies have a lot of. It is a matter of getting a consensus on how projects should be implemented and who should pay for them.
There is no easy solution to these problems, as there has been insufficient time for management systems to evolve gradually, as they did in Western Europe and North America. And large migrant concentrations can, and do, become ghettoized, as was particularly seen with immigrant societies of North America and Europe. The crucial need in such circumstances is to ensure that there is a way out of this environment. If not, social tensions will build and grievances fester. Even in developed countries this is a major challenge.
So, while the reality is far from doom and gloom, symptoms of stress abound in Asia. Therefore, the region needs help in managing its cities. And it is in everyone's interest, including the developed world, that they get this help quickly.
Asia, particularly China and India, will contribute more than half of the rise in the globe's greenhouse gases over the next 20 years. Most of this contribution will come from urban development, either directly or indirectly. If global warming is to be fought, the main battleground will, therefore, be Asia's cities.
They must become less car-oriented, denser (because densities are falling rapidly), use less energy and branch out into using different types of energy. This in turn requires the provision of new types of infrastructure at an unprecedented rate.
Asia's megacities can give billions of poor people access to a standard of living the average person in industrialized countries only gained in the last decades of the 20th century.
The challenges ahead are not beyond our wit and capacity to solve. But they will require genuine partnerships taking in cities and national governments as well as richer and emerging economies.