Megacities: the real story

We finally watched Andrew Marr’s Megacities last night. It’s a great piece of spectacular urbanism – endless cityscapes, vast crowds, skyscrapers, huge numbers, expansive metaphors. But it’s also quite badly wrong about what our urban future is going to look like. Let me explain.

The series has two basic premises. One, the world’s population is now majority urban. Two, we’ll be living in megacities – places with 10m people or more.

The first of these is very likely true. For urbanists it’s not an especially new fact, first appearing in this 2003 UN-Habitat report.

The second is part true at best. Megacities are telegenic, but most of the world’s population won’t be living in them. 

Sure, the number of megacities is rising – from two in 1950, three in 1975 to 19 in 2007. By 2025, the UN predicts  there’ll be 27. But the number of ‘large cities’ – five to 10m people – is already bigger, and growing faster. In 2007 there were 30: the UN suggests there’ll be at least 48 by 2025. More importantly, half the world’s urban population live in much smaller cities, of around 500,000 people. These may be the most common of all.

In fifteen years’ time, then, we’ll see far more Liverpools (around 400,000 people) and Londons (8m people) than Tokyos (26m people).

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Paradoxically, the biggest urban settlements are now hard to recognise as cities at all. Across the world cities are merging into mega-regions: notably China’s Pearl River Delta, the US Eastern seaboard, even the Greater South East.

Some of the numbers here are difficult to take in. An estimated 120m people live in the Pearl River Delta, the largest urban zone on the planet – China is now planning to merge nine cities in the Delta to create a single sprawl of 42m people. The Tokyo-Nagoya-Osaka-Kyoto-Kobe region may comprise 60m people by 2015, almost the entire population of the UK.

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All this may suggest that urbanisation is accelerating. In fact the opposite is true. Globally, cities grew fastest in the 1950s and early 60s: growth rates have been slowing ever since, from 4.1 percent to 2.5 percent today, and a predicted 1.8 percent by 2030. Developing countries are also on the same downward trend.  

Urbanisation runs in parallel with economic development, and so as developing countries industrialise, their urban systems tend towards steady state. Of course there is a lot of city by city variation. For example, the UN predicts Dhaka will keep growing – from 15.9m in 2007 to 22.8m in 2025. But Lagos, which has grown from less than half a million people in 1950 to over 13m in 2007, is predicted to reach just 16m in the next fifteen years.    

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Megacities makes much of the growth of urban slums. Again, the picture is complex. Over the past decade the share of urban slum dwellers has fallen from 39 to 32 percent, due to economic growth and policy interventions. But as people are flowing into cities faster than infrastructure can keep up, the absolute number of people in informal settlements is growing, and will keep growing.  

Marr stays the night in a Dhaka slum, discovering it’s quite like any other suburban neighbourhood – dirt streets and tin shacks aside. Marr echoes Stewart Brand, celebrating slum dwellers’ entrepreneurialism and inventiveness. Ed Glaeser describes slum neighbourhoods as ‘private energy, public failure’: the development challenges of poor public health, chaotic infrastructure and urbanised poverty remain considerable.

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Finally, we need to factor in the geography of climate change. Many megacities are coastal, and will be threatened by rising sea levels. Many will also be increasingly water-stressed in the years to come.

In his excellent book The New North, Laurence Smith explores the economic rise of the NORCS – cooler, resource-rich regions stretching across Canada, Scandinavia and parts of the US, Russia and China. He predicts new ‘hydrocarbon cities’ appearing across Canada and Russia, and new mega-regions like Cascadia – spanning Portland, Seattle, Vancouver and parts of NorCal.

Megacities are a great symbol of the global urban shift. But our urban future is going to be much richer and more complex than this.