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The Big Squeeze: Can Cities Save The Earth?

Monday, April 08, 2013 - 01:18 PM

Let's get dense. If we take all the atoms inside you, all roughly 70,000,000,000,000,000,000,000,000,000 of them, and squeeze away all the space inside, then, says physicist Brian Greene:

Steve Goodwin / iStockphoto.com

That's a very tight fit. So tight that in real life, it couldn't happen. It's not physically possible. Atoms won't crunch that close. But people, it seems, are willing to try. In the last century, all over the planet, billions of us have moved from villages and farms to squeeze into tighter and tighter, ever denser spaces ... like these ...

Courtesy of Michael Wolf

They are apartment towers in Hong Kong. Photographer , who has lived there for decades, pushed his camera close, so all he shows are windows and walls; there's no street, no sky, no top, no bottom, no end. The overall effect is like staring at a frozen tidal wave of residential construction, overwhelming, yet empty. You know this place is crowded, but you don't see a soul ...

Courtesy of Michael Wolf

... well, that's not exactly true. If you look closely, you can see the occasional towel set out to dry, a hint of someone looking out one of a gazillion windows ... but for the most part, what you see is a concentrated living space, thousands and thousands of apartments ...

Courtesy of Michael Wolf

... towers of them next to towers next to more towers ...

Courtesy of Michael Wolf

...without end ...

Courtesy of Michael Wolf

... and as I look at Michael's pictures (while sitting in my box-like apartment in New York under somebody else's apartment, surrounded by similar apartments, left and right of me, up and down the block), I'm thinking, "OK, this not be the most beautiful, and certainly not the most natural way to live, but modern cities allow enormous numbers of people to spend their lives in extraordinary close proximity, piling them, literally, on top of each other, and somehow, it works!

Courtesy of Michael Wolf

Because cities, even the ugliest ones, have an obvious efficiency. After all, if all 7 billion of us had to live side-by-side in two story ranch houses, or yurts — no towers allowed — we'd overrun the planet; we'd strangle the forests, the meadows, the plains. So until we learn to have fewer babies, cities may be our salvation, no?

Well, maybe.

Tim de Chant has a wonderfully creative blog called , where he thinks about population density. Last summer, he decided to try a little experiment. He asked himself: Suppose I could move everybody on Earth into a single city. How much space would that city occupy?

Would it cover half a continent? Or could we fit all humanity into New Jersey?

Obviously, it depends on which city we choose as our model. Different cities have different densities. Hong Kong, as we've just seen, is very dense. Houston, much less so. Seven billion people living like Houstonians would occupy a lot more space than 7 billion people living like Manhattanites. But how much more? Tim did the numbers, and came up with this:

Tim de Chant / Per Square Mile

In his six-city sample, New York and Paris did the best. Had Tim used really crowded cities like Hong Kong, Manila or Cairo as his model, could he have clumped the world into even skinnier spaces like Delaware or Rhode Island? I don't know.

Warning! Warning!

But he was quick to remind his readers, that cities are NOT as planet-friendly as the graph suggests. You can't take 7 billion people, dump them into Texas and assume that the rest of the Earth will be left alone. Even if nobody lived in the other 49 states, Mexico, Canada, Asia, Africa, Australia, Europe and South America, we would still need to use some of that space.

People in the Enormous City still need food, furniture, clothing, water, electricity, building materials, still need a place to store their waste. They still need water systems, farms, ranches, electricity grids, dumps, lakes, even if they never leave their city.

One Pair Of Shoes And A Bike ...

How much extra space? Well, again, said Tim, that depends. If you are happy to live with a modest diet, one pair of shoes and a bike, you won't be drawing on as much of Earth as, say an American would. If all 7 billion of us want to live like Americans, with refrigerators and air conditioners and cars and running water and TVs and strawberries in winter — then we will have a space problem.

In a very rough way, he calculated that if everybody agreed to live like the average Bangladeshi, the world could exist largely people-free.

But as soon as we get richer — even as rich as the average Chinese — the world can't carry all 7 billion of us. We need more planet. If we all want to live American-style, we'd need four more planets ...)

Tim de Chant / Per Square Mile

Or ... let's not get all doomsday about this. We could solve this problem by making fewer babies, building more efficient buildings, machines, using new, lighter materials, creating technologies that make everything less costly or wasteful, learn to live on Mars, or, in a pinch, we can be saved by a Miracle.

But the bottom line is, we have become very numerous. The other day, The New Yorker magazine ran a cartoon that . The doctor finishes the examination, sighs, and says sadly, "I'm afraid you have humans." The Earth doesn't look too pleased.


Michael Wolf's remarkable Hong Kong photographs can be found in his book , published in 2005. As for the Martian option, well, after looking at Michael's photos of Hong Kong, you can go from the most crowded of places to the most desolate and emptiest. It's a do-it-yourself panorama from the Martian surface, just in, courtesy of NASA's Rover, Curiosity. You can swing the image skyward, ground-ward, but wherever you look (you can zoom or pull), there is nothing but rock. Endless rock. Not a plant. Not a stirring, living, anything. If Hong Kong seems oppressively overbuilt, this is its achingly-empty opposite. I don't know if one image talks to the other, but there might be an invitation in there, somewhere.

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Comments [7]

Todd from Omaha

The chart that is missing is a correlation b/w urban density and how much extra-urban space is required to support it. It serves to reason that a less-dense city would be able to provide more self-support within its borders than a denser city. (More room for vegetable gardens, at least.) And then there's the question of what efficiencies arise from living closer together? The world may not be able to bear everyone at the average Chinese lifestyle, let alone the average American, but one must consider how sparsely populated those particular countries are. Surely the need to span those distances for whatever reason contributes to the consumptive nature of those cultures. Finally, the assumption that if we were all spaced evenly across the glove it would overrun the planet is one that deserves scrutiny in light of how little space it appears we might take up. Ultimately, however, I think the present arrangement--where some live close and some live far apart--is probably the best and will likely be found to be the most sustainable.

Jun. 07 2013 11:57 AM
Mark Annen from Wichita, KS

Here's the problem: population density breeds liberalism. Note that big cities are where democrats live, because they're close to the big-government programs and money they need. America's big cities are all run by democrats to provide for their democrat residents. We conservatives don't need government programs; we need our elbow room!

May. 04 2013 06:16 PM
Mark from Hong Kong

It's not really that Hong Kong's buildings are more spread out than those in Paris. It's that Hong Kong is full of mountains that can't be developed -- roughly 70% of the land is undeveloped wilderness. The actual populated area is much more dense than Paris.

This is not to say that Paris isn't a fascinating model for a densely populated city, though!

Apr. 16 2013 02:58 AM
Keith Penney from Livermore, CA

Thanks for addressing this sometimes-controversial topic. There seem to be a few "insert information here" spaces that didn't get addressed before publication. What is the name of Tim de Chant's blog? And is it photographer Michael Wolf you're speaking of in the first few paragraphs?

Also, this is encouraging news about current population growth trends:
http://www.alphagalileo.org/ViewItem.aspx?ItemId=129945&CultureCode=en

Apr. 14 2013 06:04 PM
Rob Fisher from London, UK

"The Earth doesn't look too pleased." - is pure misanthropy.

One of the efficiencies of living closer together is that people work together more so are more innovative, so invent more technology. More people means more ideas.

"We could solve this problem by making fewer babies, building more efficient buildings, machines, using new, lighter materials, creating technologies that make everything less costly" -- absolutely this. The Earth can support plenty more people in much more comfort yet.

Apr. 12 2013 11:10 AM
Eddie from New York, NY

The article begins: "So tight that in real life, it couldn't happen. It's not physically possible. Atoms won't crunch that close."

Atoms do crunch that close. Atomic nuclei packed together without their electrons are a form of degenerate matter thought to exist inside neutron stars, also known as pulsars.

Apr. 10 2013 05:36 PM
Zane Selvans from Boulder, CO

While the skyscraper canyons of Hong Kong and lower Manhattan are the canonical vision of "density", there are actually many different ways to put lots of people in close proximity to each other.

It may seem incredible, but Paris actually has a higher population density than Hong Kong, despite having a strictly enforced building height limit of 7-9 stories. The difference is that the entirety of Paris is built to that height, while Hong Kong has lots of empty spaces between their towers, and some areas of much lower density as well. We can build livable megacities if we want to. At Paris' density of ~20,000 people per km^2, a city of 10 million people takes up about 500 km^2, which means that the longest distance between two points in the city, if it's compact, is about 25 km. By bike that's just a bit more than an hour of travel to get from any point to any other point. On decent express service public transit it could be half of that time. And Paris is not an oppressive megalopolis; it's a relatively human-scale city with romantic nooks and crannies to explore. River banks and parks and promenades.

So I think it's a myth that cramming people close together to get all those efficiencies that cities are so good at necessarily means a degradation of livability. Check out Jan Gehl's book Cities for People and Andreas Dalsgaard's film The Human Scale for further exploration.

Apr. 10 2013 05:11 PM

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