1.2 bn and still counting - the vehicles!

Spare a moment to think this - where are our cities headed to in the coming decades? Especially in the context of transportation needs.

Urban areas already account for about two-thirds of world energy use, and they'll hit 73 percent by 2030, according to the International Energy Agency. The cities of the future will be bigger, and there will be more of them.

According to the United Nations, there were 21 "megacities" in 2009 -- urban agglomerations whose population exceeds 10 million. By 2025, there will be 29 -- and they'll hold one-tenth of humanity. Unless someone guides cities' development, they could lock in a high-carbon infrastructure that makes it far tougher to fight climate change.

A big chunk of this carbon will come from transportation and its infrastructure needs. In 2010, the world holds some 1.2 billion cars, trucks, buses and motorcycles.

A think-tank, Forum for the Future, recently released "Megacities on the Move," a thought exercise about where the world's cities are headed -- toward infinite sprawl and traffic, or hyper-computerized commutes marching by each other in a synchronized flow? Will they adjust by cutting carbon and pollution, or could these become permanent scourges of urban life?

Will it be Sprawlville where the personal car triumphs, at the cost of gridlock? Or Planned-opolis where computerized lives reign supreme? Or the low carbon Renewabad, where public transit takes over, or Communi-city where neighbourhoods become independent centres of innovation?

Interesting scenarios are examined. What will work may not be exactly what is pleasant, especially if we compare cities as they are now. At least model cities! For sure, the world of tomorrow will be very different. But unless we wish for chaos, and irreversible climate scenarios, it is time we started planning for sustainable cities. Not simply looking at managing the vehicles!