All posts by Tim De Chant

About Tim De Chant

Tim De Chant is creator of Per Square Mile and a contributor to The Atlantic Cities, Ars Technica, and Grist. He received his Ph.D. in Environmental Science, Policy and Management from the University of California, Berkeley. Tim's dissertation focused on the impact of urbanization on California's coastal oak woodlands. Follow him on Twitter and Google .

At least 150 companies prep for carbon prices

Wendy Koch, reporting for USA Today:

At least 150 major companies worldwide — including ExxonMobil, Google, Microsoft and 26 others in the United States — are already making business plans that assume they will be taxed on their carbon pollution, a report out today says.

It seems like national governments will be the last ones to act.

Climate change fixes may be free—or better

Justin Gillis, reporting for the New York Times:

A global commission will announce its finding on Tuesday that an ambitious series of measures to limit emissions would cost $4 trillion or so over the next 15 years, an increase of roughly 5 percent over the amount that would likely be spent anyway on new power plants, transit systems and other infrastructure.

When the secondary benefits of greener policies — like lower fuel costs, fewer premature deaths from air pollution and reduced medical bills — are taken into account, the changes might wind up saving money, according to the findings of the group, the Global Commission on the Economy and Climate.

Where the carbon dioxide comes from

We know approximately where most of the CO2 in the atmosphere comes from—developed and more advanced developing nations. But beyond that, things have been less certain. Now, though, NASA, NOAA, and a collection of universities have developed a map using satellite data that more precisely pinpoints where emissions originate.


Source: ASU

Summer vacation is an urban creation

Sam Weber and Saskia De Melker, reporting for PBS Newshour:

“The whole idea of an agrarian calendar makes it sound like it was an unthinking decision but the current school year was really a conscious creation,” said Gold, who is the author of “School’s In: The History of Summer Education in American Public Schools.”

Urban schools had a very different school schedule, but also included summer. School was essentially open year round, but was not mandatory, and children came when they could. In 1842, New York City schools were open 248 days a year, dramatically more than the 180 or so that they are open today.

In the days before air conditioning, schools and entire cities could be sweltering places during the hot summer months. Wealthy and eventually middle-class urbanites also usually made plans to flee the city’s heat, making those months the logical time in cities to suspend school.

“It was the year 2183…”

Everyone’s favorite infographic climbed the ranks of TIL over at Reddit a couple of weeks ago, and redditor FuturePrimitive penned this alternative future based on it:

It was the year 2183. Most of the planet had become uninhabitable. Since the mid 21st century, the world’s populations gradually became refugees of severe climate change, environmental collapse, unprecedented natural disasters, subsequent mass unrest/warfare, and generally intolerable levels of pollution. Only one corner of planet Earth remained remotely hospitable… a small nation-state, formed in the year 2051 after seceding from what was formerly the United States of America; a nation called TEXAS.

Over previous decades, humanity trickled, and then flooded, into Texas during mass migrations. First establishing vast, hundred mile stretches of shanty towns, now burgeoning into what is known as the TEXAS ULTRALOPOLIS: mankind’s last oasis of life in a shrinking puddle that is evaporating within the literal and figurative desert of centuries civilization’s consequences…


Shinkansen turns 50

Missed this one from Alan Flippen at the New York Times:

Fifty years ago this week, Japan conducted the first full-length test run of the Shinkansen, or what became known in English as the bullet train. A 12-car train ran from Tokyo to Osaka and back at an average speed of just over 80 miles per hour and a peak speed of 135 m.p.h. (217 kilometers per hour).

Even then, it hit speeds that would qualify today as high-speed rail.

How much has San Francisco changed? I’ll let you know


Ten years ago this month, I packed my things, said goodbye to my good friends, and started my trip halfway across the country to San Francisco. When I arrived, I found a city robed in fog and suffused by a cool so damp that only a native San Franciscan would recognize it as summer. I had left Minnesota with some hesitation, and the weather I found there certainly wasn’t reinforcing my confidence my decision.

Over the next several months, the weather didn’t change much, but my opinion did. Slowly, the city revealed itself. I discovered a city that, once confident, suddenly it wasn’t so sure of itself. I could tell that the dot-com boom was still a raw memory. Software engineers still prowled the city, but probably with less confidence than a few years previous and almost certainly with less swagger than today. As a grad student, money was tight for me, but the city in 2004 was still accessible. I ate out on weekends (frugally), frequented bars (that served cheap beer), and hosted barbecues by firing up our stove’s broiler and throwing open the kitchen window (outdoor space was a luxury I couldn’t afford.)

I lasted ten months in San Francisco before the weight of a 45-minute commute and the draw of grad-school friends finally coaxed me across the Bay to Berkeley. June 2005 was the last time I spent any significant amount of time in the city. Sure, I would return to bars with my friends or spend a few hours at a concert in Golden Gate Park or wander the Haight or North Beach like a good little tourist. But usually I spent just long enough to remind myself why I had moved away—everything was so expensive and there were so many people.

Now, having hopscotched my way across the continent, I’m heading back. Just for a week, but it will be more time than I have spent there in nine years. I’ve certainly changed—I have a job, for one, and I’ve now lived in dense cities for over a decade. From what I’ve been hearing, San Francisco has changed, too. The money that was thrown around before—that turned me off before—has only multiplied. Neighborhoods have gentrified, private buses have proliferated, and old-timers have chafed at the new round of changes. These things have all been well documented in everything from Boom to Gawker to the New Yorker.

But I’m curious to see for myself. I’m wondering if, as a visitor, San Francisco’s transformation will be apparent. Is it superficial enough to pick up on in just one week? Has ten years been long enough to throw the city’s changes into relief? Or can they really only be understood with a deeper understanding of the place, the sort that requires years to acquire?

My days will be packed with reporting fresh stories for NOVA Next, but my nights will be spent catching up with old friends, revisiting favorite haunts, and getting to know parts of the city I hadn’t known that well. I’ll be snapping photos, taking notes, keeping my eyes open, and reporting back. Think of it as an amateur ethnography, sketched quickly and by an interested observer. It won’t be scientific by any means, but I’ll let you know what I find.

Photo by Marc Dalmuder

Related posts:

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Keep your eyes to yourself

Interview: Jon Christensen on California’s cities

Low testosterone could be what made us civilized humans

Rachel Feltman, writing for the Washington Post:

According to a study published in Current Anthropology, our transition into modern civilization might have coincided with our species’ drop in testosterone.

The hormone, associated with both biologically male characteristics and aggression, makes skulls grow those heavy brows we associate with our evolutionary ancestors. Lead author Robert Cieri, a graduate student of biology at the University of Utah, said in a news release that a study of 1,400 modern and ancient skulls provided insight into how these changes might have overlapped with cultural shifts.

High-speed rail’s slow progress

Ron Nixon, reporting for the New York Times:

Still, even if the California, Florida and Texas projects all succeed, transportation experts say it is unlikely that the United States will ever have the same kind of high-speed rail systems as China or Europe.

C. William Ibbs, a professor of civil engineering at the University of California, Berkeley, said countries with successful high-speed rail projects had higher population densities, higher gas prices, higher rates of public-transportation use and lower rates of car ownership. “So it wouldn’t make any sense to have a high-speed rail train in most areas of the United States,” he said. “The geography is different and other factors are just too different.”

That’s the sort of short-sighted attitude that got us to where we are today. Also, the idea that the geography of the U.S. is somehow so different that high-speed rail can’t work? Think again.

Minneapolis buildings could produce up to 18 percent of the city’s electricity

Brendon Slotterback has a nice rundown of the solar potential of Minneapolis, concluding that rooftop solar could produce nearly 20 percent of the city’s total demand. It’s a promising number, especially considering that the population density of cities reduces the potential for solar to meet 100 percent of demand. (Suburbs, on the other hand, with their larger roof area-to-population ratio, could do exactly that.)

If you think China is urbanizing quickly now…

Chris Buckley, reporting for the New York Times about changes to China’s household registration policy, which has held restricted growth in many cities:

The government document released on Wednesday brought together commitments, some already announced, to steadily and selectively lift some of these barriers. Some cities have already made such changes, including formally erasing the division between urban and rural registration for local residents. But experts have said such changes do not mean much unless welfare, housing and other policies are also changed to overcome persistent inequalities.

In small cities with urban populations of up to one million, people with steady jobs and housing who meet requirements for welfare payments will be allowed to register as local residents. Similar rules will apply to larger cities, with stricter limits.

But the proposals say that for the biggest cities, with urban populations of five million or more, the number of newcomers must be stringently controlled, and a points system will be used to ration household registration opportunities.

So it’s not an out-and-out rewriting of hukou, but it’s almost certain to make cities more attractive to a broader swath of the population.

Genetically Engineering Almost Anything

Yours truly and Eleanor Nelsen, reporting for NOVA Next:

With gene drives—so named because they drive a gene through a population—researchers just have to slip a new gene into a drive system and let nature take care of the rest. Subsequent generations of whatever species we choose to modify—frogs, weeds, mosquitoes—will have more and more individuals with that gene until, eventually, it’s everywhere.

Cas9-based gene drives could be one of the most powerful technologies ever discovered by humankind. “This is one of the most exciting confluences of different theoretical approaches in science I’ve ever seen,” says Arthur Caplan, a bioethicist at New York University. “It merges population genetics, genetic engineering, molecular genetics, into an unbelievably powerful tool.”

Our ability to genetically modify organisms has largely been restricted to those under our close care—crops, for example. But this could bring genetic engineering to nearly anything, and gene drives could make it relatively simple to push a trait throughout a population without having to engineer millions or billions of individuals. (This all presumes the species being modified has a relatively short generation time. Insects and weeds are prime candidates.)

The first candidate being considered are malaria-carrying mosquitoes, but the real potential here will be engineering entire ecosystems. I think this could be one of the biggest scientific discoveries of the century.

“Big, expensive, controversial—and indispensable”

James Fallows, making the case for California’s high-speed rail project:

Plus, infrastructure! Of the right kind. You can think of big transport investments that didn’t pay off, especially if you start by thinking of Robert Moses. You can more easily think of ones that defined countries, eras, economies. For your old-world types, you have the Silk Road or the Via Appia. For the Japanese, the ancient Tōkaidō, or “Eastern Sea Way,” immortalized by Hiroshige, and the modern Shinkansen that covers much the same route. We Americans have the Erie Canal …

.. and the “National Road,” the transcontinental railroads, the early U.S. expansion of an air-travel infrastructure, the Interstate Highways, the Bay Bridge and the Golden Gate, the international effects of the Panama Canal, plus others. History’s record suggests that big investments of this sort are more often a good than a bad idea.

In disappearing Mexican jungle, it’s tribes vs. biologists

Joshua Partlow, reporting for the Washington Post:

Land struggles have a storied history in Mexico. They were at the heart of the country’s biggest political upheavals, dating to its decade-long revolution at the turn of the 20th century. During the 1994 Zapatista uprising here in Chiapas, the masked Mayan farmers who seized towns across the state demanded respect, an alternative to NAFTA-era global capitalism and the right to live by their own rules on their own land. The latest jungle conflict is a test for the Mexican government — one that is being replicated in other vanishing ecosystems across the country — over whether it is committed to conserving its protected areas or will let the pressures of development prevail.

The business of longform journalism on the web

Lauren Hazard Owen, writing for Gigaom:

Does Byliner’s failure mean that longform journalism on the web is doomed? Or are Byliner’s problems specific to Byliner?

Owen tiptoes around those questions, not explicitly answering either of them. But she does hint a bit, suggesting that Byliner had its own set of problems that haven’t affected its main competition, the Atavist. (The Atavist has managed to stay afloat selling access to their slick platform and likely plowing some of that money back into the longform journalism that gave it its name.)

But the larger question—is longform doomed on the web—I think the answer is, no. The rising popularity of longform articles on the web proves that there’s demand.

That’s not to say you can just start a longform site and expect to succeed. As someone who runs a site that focuses on longform science journalism, I can tell you it’s not an easy task. Keeping a site moving at internet speed still requires some quick hits, though I firmly believe that if you want to stay relevant, you have to deliver original, substantive content. If you’re going to be content-only, you have to find the right balance. But if you’re like Byliner and focus almost exclusively on longform articles, you should probably have a few other irons in the fire to keep the whole operation going.

Will cities of the future be built of wood?

Courtney Humphries, reporting for the Boston Globe:

On this scale, the construction industry is set up to work in concrete and steel, and doesn’t change course easily. Architects are unaccustomed to envisioning their designs in timber. They also face building codes shaped by wood’s long record as a flammable material. In that sense, its advocates are fighting history in their effort to bring it back.

The buildings they envision have been dubbed “plyscrapers.” Their halting arrival into the mainstream of architecture represents a test case for whether the goal of sustainability can motivate a reversal of both long-term construction norms and the laws that have grown around them. And in the long run, they also may offer the prospect of putting the look and feel of cities through a whole new transformation.

Is there such thing as an Islamic city?

Cairo at dusk

Cairo. Tehran. Karachi. What sets these cities apart in the world isn’t their arid climate or their massive populations. Rather, they’re all cities where Islam is the dominant religion. But are they Islamic cities? In other words, have the beliefs, rituals, and laws of Islam shaped cities in the Middle East and around the world?

The idea of an Islamic city was introduced by the French following Napoleon’s unsuccessful forays into Northern Africa and the Middle East. The French, thus exposed to Islamic cultures, grew a bit obsessed. But like many colonizers and would-be colonizers, they didn’t always get things right.¹

One of the developments of this decades-long fixation was the idea of an Islamic city. While the concept was probably bouncing around French salons for a while, William Marçais put it into words in 1928. He believed there are certain essential elements in any Islamic city. First and foremost is the mosque. Nearby there has to be a bazaar. There must also be a public bath where worshipers can prepare. William’s brother, George, elaborated some years later. Along with the bazaar, he added that booksellers must also sit next to the mosque. Farther out come the textile merchants, jewelers, hatters, furniture makers, and blacksmiths. It was all very elaborate and, in a way, a bit too orderly for reality.

The Marçais’ contemporaries wrote extensively about Islamic cities, but as sociologist Janet Abu-Lughod points out, many of them simply parroted the others without additional research of their own. And so the idea was perpetuated for several more years.

Toward the end of the 20th century, people started to earnestly question the idea of an Islamic city. Abu-Lughod and others, including Ahmad Bilal, argued that the forces that shape cities are never as simplistic as “Islam” or “Christianity.” Geography, climate, technology, society, and laws all play a role. Religion can, too—indeed it does on a smaller scale in Middle Eastern cities, influencing the design of homes and buildings—but it doesn’t enforce a strict blueprint.

Indeed, many of today’s Islamic cities are not shaped primarily by Islam, but by rapid urbanization. Cairo exploded from 2.3 million people in 1950 to over 10 million today (nearly 20 million if you count the metro area). The same thing happened in Tehran, which grew from around 1 million in 1950 to nearly 8 million today.

Oil wealth shapes others. In countries such as Saudi Arabia and the United Arab Emirates, ever-taller skyscrapers, massive malls, and expanding highways define their cities—and their populations, since construction is mostly done by huge pools of foreign laborers, many of whom come from nations with large Muslim populations like Egypt, Indonesia, and Bangladesh. Though they’re seldom awarded citizenship, they still bring their own unique urban experiences with them.

So can we say there is such a thing as an Islamic city? Grudgingly yes, but mostly no. There are cities that have been influenced by Islam, just as European cities were shaped by Christianity. But for the most part, cities in the Middle East and elsewhere with large Muslim populations have evolved just the same as cities have elsewhere—by adapting to their environment and their people.

  1. That is, perhaps, an understatement.

Photo by Frank Schulenburg


Abu-Lughod J.L. (1987). The Islamic city – Historic Myth, Islamic Essence, and Contemporary Relevance, International Journal of Middle East Studies, 19 (02) 155-176. DOI: 10.1017/s0020743800031822

Ahmad B. (1995). Urbanization and urban development in the Muslim World: From the Islamic City Model to megacities, GeoJournal, 37 (1) 113-123. DOI: 10.1007/bf00814892

Bonine M.E. (2009). Middle East and North Africa, International Encyclopedia of Human Geography, 82-88. DOI: 10.1016/b978-008044910-4.00298-4

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