The landscape of Asia's megacities

Are Asia's recent floods the result of bad luck, bad weather or bad design? Manila was left paralysed, with a third of the city under water and thousands evacuated from their homes. A few weeks earlier, the worst floods to hit Beijing in 30 years killed 77 people and affected nearly one million others. A year ago, Thailand's floods caused the deaths of more than 600 people. The estimated cost of the damage was 12 per cent of gross domestic product when Bangkok was inundated.

Simple bad luck? The scourge of climate change? Or uncontrolled urban sprawl? The answer is "all of the above".

Asia is on the move, with economic growth attracting millions to its cities. Urbanisation is happening at an unprecedented scale and speed. Infrastructure simply can't keep up. And climate change and erratic weather are altering the way cities need to function.

Asia added one billion people to its urban population in the last 30 years. That's more than every other region in the world combined. Moving from a 10 per cent to 50 per cent urban population took Latin America 210 years, North America 105 years, and Europe 150 years. It took Asia only 95 years. In fact, in the People's Republic of China, the transition happened in just 60 years. But the biggest difference is not simply speed - it's how these cities have grown.

"Megacities" - home to more than 10 million citizens - are proliferating in Asia at breakneck speed. Among the 25 densest global cities, 17 are in Asia. The three most densely populated large cities in the world are in South Asia. By 2025, 21 of the world's 37 megacities will be Asian.

This pace of urbanisation has not only led to traffic snarls and massive pressure on resources like water and sanitation, it has also created slums - 61 per cent of the world's slum dwellers are in Asia -- and contributes to rising crime.

Air pollution has also reached levels that seem barely livable. A staggering two-thirds of Asia's cities can't come close to pollution standards set by the European Union. Half a million Asians die each year because of pollution, a situation that is only likely to worsen, considering carbon emissions grew 97 per cent in Asia in the first eight years of the new millennium and are expected to triple by 2050 if nothing is done.

What this means is simple: crowded cities whose growth in numbers is not matched by a growth in infrastructure are vulnerable: susceptible to crime, pollution and, among other risks, flooding. More than 550 million urban Asians are considered already at risk of coastal and inland flooding in 2010. This is projected to rise to 760 million by 2025.

But there is hope. The problems are huge, fast accelerating, and expensive to fix. But green urbanisation, if managed properly, can also provide solutions.

Bigger cities whose growth in services outpaces that of industry will ultimately face less pollution, since the service sector is cleaner. Building decent infrastructure can allow manufacturers to relocate: where North Americans and Europeans have suburbs, Asia can keep its vibrant downtowns and instead provide incentives and transportation links to enable manufacturers to move to satellite cities, keeping dirty industry at bay.

Asia is not without good examples. In Delhi and Shanghai, metros connect to satellite cities. In Japan, the Republic of Korea and elsewhere, eco-cities are becoming the trend. Singapore has shown it can be both compact and "smart".

Building green technology is no longer for the future - it's starting now.

There are pilot bio-digester plants in the Philippines; pilot waste-to-energy plants in Singapore; and pilot biomass energy production in Thailand. Baoding City in the People's Republic of China created 20,000 "green" jobs in the past three years alone.

The Republic of Korea plans to have more than a million green jobs by the end of next year and Japan's green sector expects to create more than two million jobs by 2020.

Asia's urbanisation challenges are unique, and its solutions will be, too. For instance, mass transport systems must link satellite cities to ports and megacities without excessive reliance on private vehicles, otherwise Asia's cities will only be trading one form of pollution for another.

Perhaps the bigger challenge is protecting the poor and managing urban migration. This will take a delicate mix of innovation, public fortitude and more than a little common sense. Issuing land titles, removing slumlords, and providing rudimentary basic services can help.

Asia should not ignore the warning signs of recent floods. This is not just bad luck, nor is it merely bad weather. It is a reminder that policymakers and the private sector must act now to ensure the green urbanisation opportunities of today are not lost to the Asian megacities of tomorrow.