All posts by Tim De Chant

Urban trees reveal income inequality

Street trees

Wealthy cities seem to have it all. Expansive, well-manicured parks. Fine dining. Renowned orchestras and theaters. More trees. Wait, trees? I’m afraid so.

Research published a few years ago shows a tight relationship between per capita income and forest cover. The study’s authors tallied total forest cover for 210 cities over 100,000 people in the contiguous United States using the U.S. Department of Agriculture’s natural resource inventory and satellite imagery. They also gathered economic data, including income, land prices, and disposable income.

They found that for every 1 percent increase in per capita income, demand for forest cover increased by 1.76 percent. But when income dropped by the same amount, demand decreased by 1.26 percent. That’s a pretty tight correlation. The researchers reason that wealthier cities can afford more trees, both on private and public property. The well-to-do can afford larger lots, which in turn can support more trees. On the public side, cities with larger tax bases can afford to plant and maintain more trees. Given the recent problems New York City has had with its aging trees dropping limbs on unsuspecting passers-by—and the lawsuits that result—it’s no surprise that poorer cities would keep lean tree inventories.

But what disturbs me is that the study’s authors say the demand curve they see for tree cover is more typical of demand for luxury goods than necessities. That’s too bad. It’s easy to see trees as a luxury when a city can barely keep its roads and sewers in working order, but that glosses over the many benefits urban trees provide. They shade houses in the summer, reducing cooling bills. They scrub the air of pollution, especially of the particulate variety, which in many poor neighborhoods is responsible for increased asthma rates and other health problems. They also reduce stress, which has its own health benefits. Large, established trees can even fight crime.

Fortunately, many cities understand the value trees bring to their cities. New York City is aiming to double the number of trees it has to 1 million. Chicago has planted over 600,000 in the last twenty years.¹ And London has been working to get 20,000 new trees in the ground before it hosts the Olympics.

But those cities are relatively wealthy. It’s the poorer ones that probably need trees the most but are the least able to plant and maintain them. The Arbor Day Foundation is a great resource in those cases, but like many non-profits, it is stretched too thin. Compounding the inequality is the fact that most tree planting programs are local. Urban forestry has sailed largely under the federal government’s radar. The U.S. Forest Service does have a urban and community forestry program, but is woefully underfunded, having only $900,000 to disperse in grants. Bolstering that program could help struggling cities plant the trees they need. After all, trees and the benefits they provide are more than just a luxury.

  1. Though like many of Chicago’s boasts that number was probably inflated by including replacement trees.


Zhu, P., & Zhang, Y. (2008). Demand for urban forests in United States cities Landscape and Urban Planning, 84 (3-4), 293-300 DOI: 10.1016/j.landurbplan.2007.09.005

Photo by Alex E. Proimos.

Related posts:

Income inequality, as seen from space

Tree City

Urban forests just aren’t the same

Designing democracy around a ditch

Sarah Rich is on a tear over at her blog, Design Decoded. She’s already racked up seven excellent posts in her series on water scarcity, and I wouldn’t be surprised if there’s more coming.

13 percent for clean energy

Justin Gillis, writing for NYT Green:

Analyzing a survey they conducted in 2011, researchers at Harvard and Yale found that the average United States citizen was willing to pay $162 a year more to support a national policy requiring 80 percent “clean” energy by 2035. Nationwide, that would represent a 13 percent increase in electric bills.

Willingness to pay studies are always difficult size up—people are more spendthrift when they aren’t actually spending. But this study is heartening if only because it shows people haven’t given up on clean energy, even with the economy in the toilet.

Poised for a comeback

David Lepeska rounds up the photography of two academics, David Schalliol and Michael Carriere, who are documenting urban revitalization—or lack thereof. These snaps document the Midwest. They’re a subtle reminder that the region may be down, but it’s not out.

Urban ambisonics

Kaid Banfield rounds up some of the latest on ambient noise in urban environments and the effect its having on our health.

Subways converging on ideal form

Brandon Keim, writing for Wired:

On the surface, these core-and-branch systems — evident in New York City, Tokyo, London or most any large metropolitan subway — may seem intuitively optimal. But in the absence of top-down central planning, their movement over decades toward a common mathematical space may hint at universal principles of human self-organization.

I love—just love—studies like this. The peculiarities of the human brain pop up all over the place, from reading comprehension to place name density to, now, subway systems.

The Mississippi's braided past

More on rivers: A few years back, Robert Krulwich linked together a series of channel maps tracing the many paths of the MIssissippi River. The river—Twain’s river, as Krulwich points out—used to be in constant flux. Today? Not so much.

Reconstructing the Sacramento-San Joaquin Delta

Few river systems have been as heavily engineered as California’s Sacramento and San Joaquin Rivers and their combined delta. Yet despite—or perhaps because of—near constant meddling, we know little about what the river looked like before it was dammed, diked, and redirected. The San Francisco Estuary Institute is hoping to change that, and KQED Quest has taken their current findings and assembled an interactive feature with a data-rich webGIS.

The next 100 years

Joichi Ito, director of the MIT Media Lab:

One hundred years from now, the role of science and technology will be about becoming part of nature rather than trying to control it.

So much of science and technology has been about pursuing efficiency, scale and “exponential growth” at the expense of our environment and our resources. We have rewarded those who invent technologies that control our triumph over nature in some way. This is clearly not sustainable.

We must understand that we live in a complex system where everything is interrelated and interdependent and that everything we design impacts a larger system.

My dream is that 100 years from now, we will be learning from nature, integrating with nature and using science and technology to bring nature into our lives to make human beings and our artifacts not only zero impact but a positive impact to the natural system that we live in.

Mims’s perspective is spot on, too.

Tokyo's LED "fireflies"

Tim Hornyak:

The Tokyo Hotaru Festival 2012 is a modern twist on the age-old Japanese love of watching fireflies along waterways. Some 100,000 blue LED light bulbs floated down the Sumida in imitation of the insects, long celebrated in haiku and other verse.

It’s a gorgeous sight, I’m sure. But of all the coverage I’ve seen on this, not one has mentioned why Tokyo doesn’t have the real thing anymore. We should be restoring the river’s health, not merely emulating it. 

House votes to kill Census's American Community Survey

Michael McAuliff, writing for the Huffington Post:

The House voted Wednesday to eliminate the detailed surveys of America that have been conducted by the Census Bureau since the nation’s earliest days. House Republicans, increasingly suspicious of the census generally, advanced a measure to cut the American Community Survey. It passed 232 to 190.

And from Nate Berg:

While the elimination of the ACS would take a slight nibble out of the roughly $3.8 trillion in government expenditures proposed in the 2013 federal budget, its negative impacts could be much greater – affecting the government’s ability to fund a wide variety of services and programs, from education to housing to transportation.

I suspect that this—not feigned horror at violated privacy—is the entire reason for this. How much longer is this nonsense going to continue?

Callenbach and Ecotopia

A nice tribute to the recently deceased Ernest Callenbach, author of Ecotopia. If you haven’t read his book, check it out. Though it’s definitely a product of its time and place—the counterculture 1970s in the Bay Area—Callenbach spins an alternate universe in Ecotopia where Northern California, Washington, and Oregon have split from the Union over various environmental grievances.

Mapping Life

Fantastic webGIS. To explore the full home range of a particular species, search by common or scientific name and then select a layer with an “expert range map” icon, which looks like an avant-garde, neon green dove (the UI still needs a little work).

Their data seems limited to animals at the current time, but I’m hoping they’ll add plants soon. 

Via Carl Zimmer.

Our dwindling food variety

A striking infographic from National Geographic of how many varieties of common food crops we’ve lost in the last century.

Farming, circa 2050

Zenderpark, Flevoland, The Netherlands

Farms today look nothing like the farms of 40 years ago. Thanks to market and policy changes along with advances in technology, they’re larger, more mechanized, and more intensive. And while those factors will likely continue to affect farmers, there’s another looming on the horizon—climate change.

Agriculture has already seen the effects of a warming world. For example, in 2011 Texas suffered from the worst one year drought in its history. The parched earth cracked and burned, water holes dried up, and Texas’s iconic ranches lost 600,000 head of cattle. Economic losses topped $7 billion. Images of the drought are horrific. What Texas went through in just one year doesn’t portend well for the future of agriculture.

Farmers aren’t going to take climate change sitting down—they’re going to adapt. But what those adaptations will look like is less clear. A team of agronomists from Wageningen University in the Netherlands tried to predict what farms in one part of their country will look like in 2050. Though the study is region-specific, their results offer a peek at how farms in temperate regions might adapt over the next 40 years and what farmers in developing countries might do to avoid the pitfalls of modern agriculture in a warming world.

The researchers focused on farms in the Netherlands’ Flevoland province. Flevoland is, like much of the country, reclaimed from the sea. It grew out of the Zuiderzee Works project, which separated the inland Zuiderzee from the North Sea with a massive dam. The polders that make up Flevoland were specifically constructed to provide additional farmland. They were completed in three phases between 1942 and 1968.

The Wageningen researchers began by compiling data on various aspects of farms in the Flevoland, including their economic output, farming intensity, degree of specialization, and market niche (production-focused, conservation oriented, or entrepreneurial). They looked as far back as 1986 to see how Flevoland farms have evolved in recent decades and used that information, along with expert input, to tune a model that predicted how farms might change in response to global warming of 1–2 ˚C by 2050.

The model also took into account how the world will react to climate change. That part of the model was based on two scenarios developed by the United Nations Intergovernmental Panel on Climate Change (IPCC), specifically the A1 and B2 scenarios. The A1 scenario assumes climate change will be dealt with on a global scale. It predicts that globalization will continue, economic output will rise rapidly, technology will advance apace, and economic and cultural disparity between nations will decline. B2, on the other hand, assumes slightly lower population growth, intermediate economic growth, more regionalization, and more disparity between regions in technological advancements.

Under the A1 globalization scenario, the model predicted continued increases in farm size. Entrepreneurial farms—those that accepted tourists, for example—grew in share substantially, to about 24 percent. Farms with a conservation bent disappeared, and Flevoland’s focus shifted from root crops like potatoes to arable crops like wheat or soybeans. The regionalization scenario painted a different picture, in some respects. Farm focus was almost equally divided among production, conservation, and entrepreneurship. Farm size held steady with today’s levels, as did intensity and types of crops grown.

Though this study focused on one province in the Netherlands, it details some potential futures. What type of world we become—a globalized, tech-heavy A1, a regionalized B2, or some other vision of the future—will affect how farms adapt to climate change. Some aspects of the future are not entirely under our control—population growth remains an untamed beast, for example. But others are, like crop subsidies and technological progress. Policy has played an important role in the last 40 years, and there’s no reason to think that will change. That may seem depressing to some people—subsidies have discriminated against small farms, for example—but it can be heartening, too. Policy is something that remains under our control. That means we can still play a role in determining how we’ll get our food in the future.

This study also can also help non-temperate farmers prepare for climate change. By identifying where modern agriculture will likely fall short under certain scenarios, farmers in developing nations can better evaluate whether or not to adopt current methods. Many of them may have missed out on the Green Revolution—especially in Africa—but that may end up being beneficial. Just as some developing nations skipped land lines and went straight to cell phones, farmers unaccustomed to modern production techniques could adopt new methods, approaches that could better prepare them for a changing climate.


Mandryk, M., Reidsma, P., & Ittersum, M. (2012). Scenarios of long-term farm structural change for application in climate change impact assessment Landscape Ecology, 27 (4), 509-527 DOI: 10.1007/s10980-012-9714-7

Photo by Radio Nederland Wereldomroep.

Related posts:

Spare or share? Farm practices and the future of biodiversity

Coaxing more food from less land

Small farms in modern times

An ill-fated monument to electricity

Matt Novak, writing at his brilliant Paleofuture:

In 1922, eccentric magazine publisher Hugo Gernsback decided that the world needed a 1,000-foot tall concrete monument to electricity. Gernsback imagined that this monument might last for thousands of years, and rather than some static behemoth stuck in time, the interior of his monument would be constantly changed to reflect the technological advances of each new generation.

A museum of modern technology, to be housed in a skeuomorphic monolith that was all-but-certain to become outdated. I’m guessing the irony was lost on him.

What form would a Gernsback monument take on today? A solar panel? A windmill? A server farm? Somehow those don’t seem to be equivalent to a dynamo. Maybe a better question is, is there anything from today that is worthy of or fitting for skeuomorphism on a monumental scale?

Lights out for research satellites?

Rachel Nuwer, reporting for the New York Times:

Earth-observing systems operated by the United States have entered a steep decline, imperiling the nation’s monitoring of weather, natural disasters and climate change, a report from the National Research Council warned on Wednesday. Long-running and new missions are frequently delayed, lost or cancelled because of budget cuts, launch failures, disorganization and changes in mission design and scope, the report said.

Bad news. 

And here on the 12th floor, a food truck

Glenn Collins, reporting for the New York Times:

Every weekday in recent months, fancy-food trucks have been rumbling into the gigantic freight elevator of the Starrett-Lehigh Building at 601 West 26th Street in West Chelsea. After being hoisted aloft, they roll out into the concrete truck bays on the upper floors of the 81-year-old, 19-story commercial building. There, they post menus and proceed to sell inventive meals to office workers and their guests.

Totally awesome? Or a sign that the food truck craze has jumped the shark? I can’t decide.