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 .

Earth’s Land Mammals by Weight

Randall Munroe rounds ‘em up. Spoiler: Wild mammals barely make an appearance.

Being only about mammals, this is obviously biased. (Including insects, for example, would change the picture dramatically, as would bacteria, which Munroe notes in the image’s title tag.) But it does say something about our preference for similar forms of life, both for consumption and companionship.

Global Forest Watch

The World Resources Institute has assembled a comprehensive web map that tracks deforestation and aforestation since 2000. Adjust the interval to see trends over time. 

One thing I like is that it isn’t limited to the tropics. Discussions about deforestation often focus on that region of the world, as though it houses the only remaining “pristine” ecosystems. Global Forest Watch also trains the spotlight on temperate—and developed—countries, which play a significant but often overlooked role.

Google to pay for SF free Muni for youth program

John Coté and Marisa Lagos, reporting for the San Francisco Chronicle:

Tech giant Google has agreed to donate $6.8 million to San Francisco to fund free Muni passes for low- and middle-income youth, under a deal brokered by Mayor Ed Lee, city officials said Thursday.

Good on them. This probably won’t do much to stem the animosity many in the city have for Google, but it’s a start. Still, it highlights a cascading series of civic problems.

  1. This sort of thing should probably be covered by the city’s budget, which should be funded by taxes. 
  2. Problem is, Google isn’t based in San Francisco and so doesn’t have to, or actually can’t, pay taxes to the city. So they donate. But in donating they get to pick and choose which parts of the city they support. Not saying this is a bad choice, but still, they have that luxury.
  3. What this really reveals are the shortcomings of local governance. Cities are increasingly smaller parts of regions that have much bigger problems. Regional governments aren’t designed for the way we live today.

Why It Takes Decades to Produce a New Solar Material

Yours truly, writing at NOVA Next about perovskite, a new photovoltaic that’s been getting a fair amount of press:

The road from the laboratory to the rooftop can be filled with unexpected speed bumps, something known all too well by researchers and manufacturers of copper indium gallium selenide, or CIGS, a photovoltaic material that’s just recently available on the market. In fact, the story of CIGS could be viewed as a cautionary tale, one that might temper some of the excitement surrounding perovskite.

Why you could soon be buying your electricity from Elon Musk

John McDuling, writing for Quartz:

In a note published this morning, the investment bank posits that Elon Musk’s electric car company, which will unveil its plans to build  the world’s biggest lithium-ion battery pack facility this week, is poised to disrupt the $1.5 trillion electric utility industry. Tesla doesn’t just make high-performance automobiles, Morgan Stanley analyst Adam Jonas argues, it’s also producing a mobile fleet of electrical grid storage.  The 40,000 Tesla vehicles already on the US roads contain about 3.3 gigawatts of storage capacity, roughly 0.3% of US electrical production capacity and 14% of US grid storage, he estimates.

True tales of how various species went extinct

Frank Swain:

The Pyrenean ibex was a type of Iberian wild goat that lived in Cantabrian Mountains of northern Spain. No one is sure what caused the species to decline, but the last surviving individual, a female named Celia, was crushed to death under a falling tree in January 2000.

How the Netflix-Comcast deal could change the internet landscape

Shalani Ramachandran, reporting for the Wall Street Journal:

Netflix Inc. has agreed to pay Comcast Corp. to ensure Netflix movies and television shows stream smoothly to Comcast customers, a landmark pact that could set a precedent for Netflix’s dealings with other broadband providers, people familiar with the matter said.

In exchange for payment, Netflix will get direct access to Comcast’s broadband network.

Previously, these peering agreements didn’t involve money. After all, Netflix pays for their connection to the larger internet and so do consumers. By extracting payment from Netflix, Comcast is essentially double-charging for traffic that consumers already paid for. This gives Netflix a priority slot in the process, but it also violates the principle of net neutrality says that providers like Comcast shouldn’t prioritize one source of traffic over another. 

Many people have predicted (and feared) that the day would come when a content provider would pay an internet provider for priority access to broadband subscribers. Now that it’s here, I can’t help but wonder why it happened now and with Comcast, especially when you consider that Netflix and Verizon have also been duking it out over the same issue (arguably in a more public way).

The answer, I think, is that Netflix is using Comcast’s bid to buy Time Warner to its advantage. As a part of the buyout approval process, both the FCC and the Department of Justice will be scrutinizing Comcast’s moves and market power in the coming months. Having made this payment, Netflix can make the case to either the FCC or the DoJ that pre-Time Warner Comcast has used its dominance in broadband—about 27 percent of the market—to extract payments from content providers like itself. Netflix could argue that if the Time Warner deal goes through, Comcast will have nearly 50 percent of the market, and its bargaining power to demand such payments will further increase. 

Netflix’s deal with Comcast is defensive in two ways—one, it helps ensure that the streaming media company doesn’t lose customers because of poor video quality, and two, it’s an attempt to convince the government that Comcast and its peers need to be reigned in. How the government reacts to it will almost certainly shape the future of the internet.

Where children go hungry in the world

Every day, tens of millions of children go to school—or to bed—hungry. Not only does it take a toll on their studies, hindering their chances of a better life, it also stunts their growth and makes them more susceptible to illness and disease.

Scroll and click around the map to see where in the world children are underweight, which is defined as two standard deviations below the median of the NCHS/CDC/WHO International Reference Population. It’s a pretty good indicator of kids who are chronically hungry.

The data covers 1990-2002 and isn’t available for all regions (those that are unavailable appear blue on the map). The raw data was compiled by the Center for International Earth Science Information Network.

Related posts:

If the world’s population lived like…

Coaxing more food from less land

Can we feed the world and save its forests?


Geographic distribution of U.S. economic activity

I wasn’t surprised that cities are responsible for the majority, but the degree of concentration is striking.

There’s some debate in the Reddit thread about whether this actually represents where the economic activity is taking place—in other words, do people commute from cities out to worksites? I don’t think accounting for that would change things substantially. Gizmodo seems to have some issues with it, too, but they don’t specify what they are.

And while the map is thought-prokoving, I think it’s unfair to rural regions. After all, without them, cities couldn’t exist.

Highest rents in the U.S.

Alissa Walker, writing for Gizmodo:

Two North Dakota cities are in the top five thanks to a burgeoning oil industry that’s building instant cities in the Great Plains. The explosive increase in oil production has transformed Williston and other cities into boom towns with dramatic population spikes. In Williston, a city on the edge of the Bakken Oil Fields, the population has doubled in the last five years, from 14,700 in the 2010 census to over 30,000 people today. The growth is akin to the way the Gold Rush quickly urbanized parts of California in mid-1800s.

I wonder if North Dakota’s urbanization will persist. California has lots going for it, including fertile farmland, ocean access, and warm weather. Those and more helped it remain relevant long after the gold rush was over. 

The Real Reason Why Techies Are the New Yuppies

Annalee Newitz:

As people lose jobs in the middle of the country, and the income disparity between city dwellers grows beyond anything we’ve known in this generation, it’s handy to have a caricature to blame. Because who really wants to do all the mental math to figure out that it’s not just a few shitty techies, but in fact an economic system that over-rewards some people while under-rewarding almost everybody else? It’s easier to hate over-simplified symbols than it is to challenge our whole troubled economy.

The Scientist Who Took on a Leading Herbicide Manufacturer

Rachel Aviv, reporting for the New Yorker on Tyrone Hayes’s research on the herbicide atrazine:

Hayes has devoted the past fifteen years to studying atrazine, and during that time scientists around the world have expanded on his findings, suggesting that the herbicide is associated with birth defects in humans as well as in animals. The company documents show that, while Hayes was studying atrazine, Syngenta was studying him, as he had long suspected. Syngenta’s public-relations team had drafted a list of four goals. The first was “discredit Hayes.” In a spiral-bound notebook, Syngenta’s communications manager, Sherry Ford, who referred to Hayes by his initials, wrote that the company could “prevent citing of TH data by revealing him as noncredible.” He was a frequent topic of conversation at company meetings. Syngenta looked for ways to “exploit Hayes’ faults/problems.” “If TH involved in scandal, enviros will drop him,” Ford wrote. She observed that Hayes “grew up in world (S.C.) that wouldn’t accept him,” “needs adulation,” “doesn’t sleep,” was “scarred for life.” She wrote, “What’s motivating Hayes?—basic question.”

I arrived at UC Berkeley a few years after Hayes had cut ties with Syngenta, and rumors of this sort were definitely in the air. Couple that with other controversial university funders—Novartis and BP among them—and you can see how it was an interesting place to be at the time.

The unsealing of the Syngenta documents isn’t new, but Aviv has used them along with extensive reporting to craft a riveting narrative of the whole saga.

In 40 years, will we live in cities in the sky?


At the end of 2013, the journal Cityscape put the following statement to contributors and asked their opinion of it: “In 40 years, the average person will live closer to her neighbors and farther from the ground than she does today.” This is a critique of one response. More to come…

Two visions. One dystopian, filled with social decay, segregation, and violence. The other optimistic, light, harmonious, and elevated. Jill Stoner, a professor of architecture at the University of California, Berkeley, offers them both as possible visions of a denser future. While she acknowledges that either is possible, she hopes for the latter.

To flesh out her dark version of the future, Stoner draws on a novel by British novelist J.G. Ballard. Having been crafted by a fictionist, it is captivating in its detail. There’s a new London skyscraper that houses wealthier residents as the floor count increases. Each income segment is buffered from each other in various ways, but they still find a way to wage class war against each other. The novel begins by starting at the end with the culminating event—a doctor eating another resident’s dog. That’s how low things have gotten.

It is, Stoner argues, a caricature of late 20th century views on skyscrapers. Once heralded as a way to save cities, residential towers in many cases ended up destroying much of what made urban areas successful. To Stoner, though, the skyscraper isn’t dead. While she sympathizes with those who favor “traditions of townships, neighborhoods, and gardens planted in terra firma behind firmly owned houses”—arguably the New Urbanists—she sees more promise in building up, way up. Because the idea failed once doesn’t mean it will fail again. In fact, she argues that it has to succeed because we can’t pretend that a neighborhood-centric mid-rise city is the only template.

Her grand vision, less vivid than that of Ballard’s but still reasonably compelling, is a city of towers linked by boulevards some 20 stories above the ground. Below, the ground has gone fallow, if you will, left to return to nature. Sort of a mashup of the aerial walkways of Star Wars’ Coruscant and Tyler Durden’s dream of wild freeways.

How likely is that in 40 years? Not very, a fact which Stoner admits, stating it’s more like 100 years off. But even then, will we all be living in skyscrapers, seldom touching the ground? It’s certainly possible, though I think it would require a transformative technology that we don’t have or can’t envision.¹ Right now, our lives are firmly rooted on the ground—or in software. We walk, we drive, we ride, we chat, we message. It all happens on—or under—solid ground. The comparatively little travel we do in the skies hasn’t exactly fostered density

Unless something radical changes in the next century, it’s unlikely that towers will play as central a role as Stoner envisions. Yes, we’ve inched toward her future in the last 100 years, but we’ve also backed away from it. Our cities—at least here in the U.S.—grow more dispersed every year, and self-driving cars, the current technology that’s most likely to change cities in the coming decades, is likely to hasten that trend. Time will tell, of course, but for now, I can’t see Stoner’s vision coming true.

  1. Those lofty visions of the future that we see in Star Wars and other sci-fi tales imply that aerial living arose because anti-gravity became commonplace. Only then were we able to really make use of the third dimension.


Stoner, Jill. 2013. “High Optimism.Cityscape 15(3).

Photo by z_wenjie

Related posts:

Planet of the cities

When everyone lives in a city

How self-driving cars will change cities

Inequality in India

Ellen Berry, writing for the New York Times:

Hunt for an apartment in New Delhi’s wealthy neighborhoods and this immediately becomes clear: Spacious homes feature tiny, airless spaces known as “servants’ quarters.” Elevators are sometimes marked with signs reading “Not for use by servants.” Landlords asked about installing dishwashers often respond with blank stares, because servants wash the dishes.

That excerpt makes it sound pretty callous, which it is in many ways, but the reality seems far more nuanced.

Fast food joints as social spaces

Sarah Malsin Nir, reporting for the New York Times:

Behind the Golden Arches, older people seeking company, schoolchildren putting off homework time and homeless people escaping the cold have transformed the banquettes into headquarters for the kind of laid-back socializing once carried out on a park bench or brownstone stoop.

There’s an element of the “everyman’s Starbucks” to this article, but it’s more than that. People will always find places to socialize. If owners of the private spaces don’t like it, then we as a society need to consider investing more in public spaces where everyone is welcome.

The Inefficiency of Inequality

Daniel Altman, writing at Foreign Policy:

If you believe that poor people are poor because they are stupid or lazy — and that their children probably will be as well — then the issue of inefficient allocation disappears. But if you think that a smart and hardworking child could be born into a poor household, then inefficient allocation
is a serious problem. Solving it would enhance economic growth and boost the value of American assets.

Industry Awakens to Threat of Climate Change

Coral Davenport:

Today, after a decade of increasing damage to Coke’s balance sheet as global droughts dried up the water needed to produce its soda, the company has embraced the idea of climate change as an economically disruptive force.

“Increased droughts, more unpredictable variability, 100-year floods every two years,” said Jeffrey Seabright, Coke’s vice president for environment and water resources, listing the problems that he said were also disrupting the company’s supply of sugar cane and sugar beets, as well as citrus for its fruit juices. “When we look at our most essential ingredients, we see those events as threats.”

It’s a step, but if Coke were really serious, they’d have made the CEO available for comment, not the VP for the environment.