Ideas

In Some Places, Environmentalists Should Be Arguing for More Development. Here’s Why.

September 30, 2015

Follow Rob
Golden Gate Heights in San Francisco, California. Photo © Daniel Hoherd/Flickr through a Creative Commons license

Zoning is often viewed as a friend of conservation. But could some zoning actually be detrimental to conservation goals?

It may seem almost heresy for environmentalists to argue for more development in certain places. But that’s exactly what I will argue in this blog. Let me explain.

On a recent trip to the San Francisco Bay Area, I saw a worrisome sight I often see in America cities. In North Berkeley, you can be just a few blocks from a Bay Area Rapid Transit station, which offers an easy 30-minute commute into downtown San Francisco.

And yet the neighborhood is single-family, detached homes that house relatively few people. Zoning has made it so, by prohibiting certain kinds of structures (apartment buildings, for instance) that could house way more people.

This is sometimes called exclusionary zoning, when the primary purpose is to restrict further development or change in a neighborhood. It’s a change from (arguably) the original purpose of zoning and building codes, which was to protect public health and safety (by preventing a factory with smokestacks being built next to residential housing, for instance). It’s also massively common in the United States- one study classified 80% of U.S. urban land as having minimum lot sizes that prevent more dense development. On some parcels, that may be quite appropriate, for environmental, health, or safety reasons. But it is striking that 4 out of 5 landowners are prevented from developing more densely, even if they wanted to.

Environmentalists have to tread carefully when discussing zoning codes. We want the government to be able to use zoning codes to protect public health, ensure access to public parks, and protect at least a few parcels of open space in a metro area. We want governments to be able to plan to make cities more walkable, greener, healthier places. So we respect and support strong zoning codes. Yet the massive exclusionary zoning in many cities has restricted housing supply near cities, pushing up prices there and contributing to urban sprawl, and the spread of new low-density neighborhoods in the fringes of urban areas.

One study I worked on in the Bay Area looked at this process. Parks in the Bay Area, while extensive, didn’t restrict the housing supply much, since land protection was overwhelmingly on sites that were either too steep or too wet to support dense development. The main limitation on housing supply was simply the large amount of area restricted by zoning to single family homes.

Suburban development. Photo © Dan Reed/Flickr through a Creative Commons license
Suburban single family house development. Photo © Dan Reed/Flickr through a Creative Commons license

The Bay Area is actually denser already than many U.S. metro areas, and regional groups like the Greenbelt Alliance are actively trying to encourage infill development, increasing housing density within the urban footprint of a city rather than expanding the urbanized areas. The Association of Bay Area Governments has mapped places for infill development, and outlines changes to zoning and tax codes that could make infill development more possible. The Metropolitan Transportation Commission has promoted transit-oriented development, to support this infill development. Despite all these efforts, I was struck during conversations in the Bay Area by how controversial infill development can be. Change is hard. It is hard for people to accept changes in neighborhoods they have come to know and perhaps love.

I have come to believe that in the proper places, environmentalists need to argue for allowing more development. As part of a well-planned city, allowing more density near urban centers would prevent sprawl and economically revitalize urban centers.

It will limit suburban sprawl, and help protect biodiversity in remnant habitat patches on the fringes of the city. Development alone won’t, of course, ensure that housing prices are affordable, and cities will also need to have programs to ensure some affordable housing for lower income residents. But allowing more housing units on previously low-density parcels will help reduce housing prices somewhat city-wide.

The alternative to infill development is clear: U.S. cities will continue to sprawl out. While much has been written about the preference of millennials for urban life, the overwhelmingly majority of new houses in U.S. cities are still built on the urban fringes. One of the greenest things U.S. cities could do is get a bit denser. This push for infill development and walkable development is not a new thing for urban planners and new urbanists. But for the conservation movement it is still a new, sometimes hard step, to openly call for more development in certain key, appropriate places.

I saw this in my own city of Washington, D.C., where there was an effort to develop a light rail line (the Purple Line) on a previously cleared old railroad right-of-way, bought by the city decades before explicitly for this purpose.

This effort has been delayed and stymied by landowners along the route worried about the loss of a few hundred trees along the rail line, and the change that will come to their neighborhood as more people can access it. Some local environmental groups have fought the Purple Line, to protect those few hundred trees, but most have fought to allow the rail line to happen. Infill and denser development have to happen for the greater environmental good, and it is a sign of maturity for the conservation movement to be willing to say so.

Rob McDonald

Dr. Robert McDonald is Lead Scientist for the Global Cities program at The Nature Conservancy. He researches the impact and dependences of cities on the natural world, and help direct the science behind much of the Conservancy’s urban conservation work. More from Rob

Follow Rob

Join the Discussion

Please note that all comments are moderated and may take some time to appear.

23 comments

  1. I live in a neighborhood inside Austin. A neighbor discussed efforts to build a seocnd smaller house on his property. The reason he can’t is a requirement for parking!! Each structure must have available off street parking spaces for 2 vehicles! Too bad. Our neighborhood is served by 3 different bus lines, and is within 1/2 mile of about 100 businesses, including low & high end restaurants, groceries, pharmacies, schools, and an Alamo Drafthouse theatre – that I have walked to on many occasions. This proximity is why I moved here: I don’t truly need a car for most things.
    Oh well. Austin is current ly over regulated.
    I really like the concept of your article.

  2. Denser housing could work as long as it is well-planned. The problem is that developers all have their own ideas and cities unfortunately cater to them. Denser housing with a plan will just bring chaos and crime.

    1. I believe that the science is pretty mixed on the assertion that increased density leads to crime. But generalizations in general are pretty mixed.

  3. The answer to this question is too obvious. Population control, not “density” studies! It’s called BIRTH CONTROL! Make love, not babies!

    1. I think we do have successful population control but the current and future population want to move to the cities.

  4. In some senses would-be developers have been their own worst enemy. In the 1970s in Berkeley, for example, citizens passed by initiative a Neighborhood Protection Ordinance that froze single-family zoning in much of the flatlands — a direct response to a proliferation of cheaply-built 4plex and 8plex apartments placed randomly without regard to context. The ensuing 40 years of civic “discussion” has manage to focus infill development on major streets with access to transit and managed the transition of the downtown district from large-village to small-city in character. Along the way the local Sierra Club and other conservation and environmental groups became advocates for smart-growth-style greater density. But opportunity sites are now few, and the proportion of land still dedicated to low-density housing is still, in the long term, unsupportable. Any major change in character from here will take another generation for “discussions” at hundreds of public meetings, which are a sort of civic pastime.

    1. “…without regard to context…”

      Every time I see this phrase, I am forced to wonder: *whose* context serves as the canonical context? I know that you are talking about the context of “a neighborhood of little 1-story bungalows” being invaded by 4/8-unit apartment buildings, but how did those bungalows get there in the first place? Or more precisely, is there something objective, besides the bungalows — which were built on land that had not previously supported a neighborhood of bungalows — that defines the context?

      I’m 100% sure that there was someone whose “context” was ruined by the appearance of that neighborhood of bungalows.

      The word “context” has become the ultimate provincial shibboleth: it somehow presumes that there is a single “natural” state of the built environment. We presume that the “bungalow neighborhood” was invaded by out-of-context apartment buildings, but somehow reject the notion that the “bungalow+apartment building” or the “pre-bungalow prairie” contexts might be equally valid.

  5. I spend way too much of my life at Planning Commission meetings across the Bay Area advocating for more infill housing. More often than not, across the aisle, is a representative from the Sierra Club, or another environmental group complaining about traffic, emissions, shadows cast by tall buildings, bird strikes, noise, you name it. they don’t understand that development follows the path of least resistance and if you fight development in cities next to transit, you’ll find it sprouting in what was once ag land in eastern Contra Costa and the San Joaquin Valley. Almond orchards don’t file CEQA lawsuits, NIMBYs masquerading as environmentalists all too often do.

  6. Enjoyed this article although I personally don’t like seeing more dense communities myself. The photo of the single family development is too dense for me. If we put more people in urban areas, I believe at the same time, we need to help create more natural friendly spaces for people with things like rooftop gardens and green roofs, more parks, and more commitment to energy efficiency . I grew up in Nashville and personally, I hate how it’s getting too urbanized and no real commitment to green spaces (so much greenwash!). I would get more excited if I saw some of the developers taking their cue from Germany and committing to solar than just building. Having said this and talking about ecosystems, in the city with all the desity, I’m afraid one will never hear again the Whippoorwill or the Bobwhite. In Nashville, I grew up in now what is known as midtown. I heard these birds. I also could see the sun rise. In that area, buildings are going up and these things are nonexistent. Perhaps we need more talk about curbing population in general.

  7. We just returned from a visit to Turkey. Almost all of the urban residential buildings are higher rise apts. Many citizens own their own home (apt.) mainly, I assume, because they are affordable. Maybe this is a solution to the urban sprawl we build in to many of our communities and making homes more affordable.

  8. Among the “wants” of environmentalists for cities wouldn’t it be wise to include keeping the city prosperous, even as an afterthought?

  9. This article misses a couple of important points. If people have chosen to live in a low density neighborhood outsiders cannot come in a change zoning to affect other issues without their consent. Also, gentrification often takes place replacing working poor with upper class when rezoning takes place.

    How about focusing on reducing over population and leveling off the number of people so we don’t have to constantly accommodate more and more people.

    The cause of urban sprawl originally was the result of people wanting to get away from cities. Now some people are beginning to return to cities, but rezoning is not always the answer. Maybe smaller houses and smaller apartments to accommodate more people.

  10. Rob is not addressing the Elephant in the Kitchen (more on that later).

    Saving lands for Wildlife and In-Fill of Cities.

    Rob is correct that higher density (high-rise) cities MIGHT help to alleviate urban and suburban sprawl,
    which MIGHT help preserve wild lands, but Rob also fails to consider the typical outcome when higher densities are allowed to occur, without any corresponding requirement of MORE open space acquisition within the city zones (for human parks) but, more importantly for wildlife, requirements for purchases of large wild land and wetland zones in the regions outside the city, but well away from human impact zones near the city.

    It is clear that thousands of cities around the globe have already allowed massive, high-rise, super dense urban development, miles and miles of steel and concrete canyons that house millions upon millions, but the wild lands that once existed around those cities have not been saved as wild lands in perpetuity…not at all.

    Those wild lands and wetlands are always under pressure and typically are allowed to convert to low density residential, large estates for the rich, airports, hospitals, farms, businesses, power and water generation facilities, and garbage and sewage facilities that serve the needs of the bloated and
    “very densely-packed” cities. The growth never stops, and the impact zones on wild ecosystems continues to radiate outwards from the ever growing and ever more densely-packed cities.
    It just never ends!

    Look at the evidence! The coastal regions of the U.S. have many highly dense cities, but the states that have such large and dense cities have also LOST nearly ALL of their wild lands and wild species. New York State may have “woods”, but most of the wildlife in New York State is gone, unable to live near humans, either due to the needs of the wild species or due human impacts created even in cities far away from those (once) wild woods.

    Note the absence of bears, wolves, cougars, myriad bird species, and so many other species that once existed in those states, and where the few wild species do remain, they are viewed as scary pests or the odd anomaly. Their numbers are gone or at extinction levels. Sparrows, Pigeons, rats, mice, cockroaches, raccoon, and coyote are the few species that have some success living near humans.

    Even the interior of the U.S., far from cities or suburbs, is impacted by the ever growing “high-rise” cities! People eat food and need resources of all types, so the wild lands of the interior are always under non-stop pressure to convert to agricultural lands, mining areas, logging, oil, gas, coal extraction, even clean wind and solar farms, dams for hydro-electric and flood control, river water diversions through pipes and canals to hydrate the city people, etc. etc, all of which means that wild lands, wild species, and wetlands are lost, year after decade.

    So what is the answer?

    The issue that Rob is NOT talking about is the Elephant in the Kitchen that NO one wants to talk about…the taboo topic of the ages.

    OVER-Population.
    Yes, the verboten word.

    Over-population is an ignored FACT, both here in the U.S. and world-wide. Over-population has always been the culprit in the steady destruction by humans of wild lands, wild species and even the destruction of resources (like healthy soils and clean water and depletion of fish) that allow humans to live far better, far cheaper, and far healthier and happier lives.

    Wars are nearly always due to the cycles of over-population locally with destruction of local resources, followed by invasion and war on less populated areas, theft and corruption inflicted on the native people and the resources, and the cycle goes round again, ever larger with each cycle.

    The Sahara Desert, under growing human population, has doubled in size the past 2000 years, a large part of which is due just to over-population and sloppy land management and the killing off of large animals and predators that actually help to keep the wild ecosystems healthy and diverse in species types. Wild food from over-hunting became scarce, and agriculture and grazing become the new food source but ultimately depleted and poisoned the soils and water.

    The MiddleEast has suffered recurring wars and hunger due to resource depletion that is a direct result of over-population within that region and also over-population of outside regions (U.S. and Europe) that use and deplete resources (by force (war or coercion) or by trade agreements).

    China and Indonesia have suffered massively from their own bloated populations, but also from demands and financial incentives (and corruption) from Europe and the U.S. who want resources and cheap labor from those regions of the world. The result of over-populations (both in the east and west) is that China has now polluted most of its farmlands and destroyed 60% of its wetlands, and China’s wetlands provide 1/6th of the world’s global fish catch, and it is dying at a rapid rate.

    Thus, China, the huge and hungry child of U.S. outsourcing policies will now hone in on the American continent’s resources to feed its massive population, so the impacts will come roaring back onto the U.S. as our lands and waters are depleted to feed China, which may not be able to feed itself in the future, and the fault lies both in U.S. over-population, Asian over-population, and policies that hurt both regions over time and are destroying resources in both regions. Over-population and exploitation of humans and natural resources go hand in hand.

    Indonesia continues to strip rain forests at an alarming rate for Palm Oil and other tropical products sold around the globe. Wild life in the rain forests is crashing and may not recover now and even indigenous people are being driven from their rainforest homes, destined to be another vast group of poor and starving city dwellers or refugees. Indonesia is one of the most over-populated and poverty stricken regions on the earth, vulnerable to corruption from outside countries who seek to exploit their resources and their people.

    Rain forests harbor species that have provided amazing medicines for people, and we’ve only studied about 1% of all rain forest species to date, but we are stupidly wiping out rain forests, to our own detriment, just for “tropical food or wood products” that are not necessary for most people around the globe, just a luxury.

    U.S. over-population Impacts
    California’s Great Central Valley, known as the great food source for the nation and now expanding in products to feed the world, is 13 million acres in size. The valley in the 1800’s held 4 million acres in wetlands (1/3rd of the valley). Those wetlands provided vital habitats for spawning fish that provided fantastic and abundant fish for humans. Wild salmon and steel head trout once existed in great numbers in nearly all of California’s rivers as far south as San Diego County. They are nearly all gone now (but could be restored if the habitat is restored). Myriad bird species, ducks, geese, antelope, elk, all depended upon the wetlands, but their numbers have crashed to 10% or less of their historic numbers. Those animals once provided cheap and easily accessible food, until over-population and agricultural pressures destroyed those habitats.

    The wetlands of California’s Central Valley provided water reserves during times of drought and recharged the water table under the valley. Since over 90% of the wetlands are gone, the ground water continues to fall rapidly, even in years of heavy rainfall. Human over-population has converted most of the wetlands to farms and development is taking its toll on what remains of wetlands, and the groundwater, so desperately needed for agriculture is drying up.

    Is the U.S. over-populated with just over 4% of the world population?
    The U.S. is now at 322 million people but consumes (per average U.S. person) a rate that is 5x the rate of the average person in other countries, so we live as if we are a nation of over 1.6 Billion (with a “B”), causing more consumer impact than any other nation on earth (for now). And the U.S. is expected to grow to over 420 Million by 2065 (another 30% more people than in 2015).

    But the most of the rest of the world is grossly over-populated too, rising in population far faster than the U.S. is, and the global population, understandably, is seeking to live a far better quality of life than they do now (more consumerism, globally).

    So, even if the U.S. had a far smaller population to lesson our impacts, the problem still remains since our “Global Trade policies” will ensure that over-population around the globe will drive demands on U.S. lands and oceans for more energy resource acquisition, more farming, more ranching, more fishing, more development, more immigration, more refugees to this country, etc. etc.

    Non of the impacts on global wild lands, wild species (terrestrial and aquatic) will be saved UNless and until we have a very fast and brutally honest look at the culprit…World Wide Over-Population that will ALWAYS and continuously destroy nature and drive all wild species into extinction, a fact that is well under-way the past many centuries, with only a few years left to turn the corner and save these species and bring them back to healthy numbers in wild settings.

    Human survival and human happiness depends on whether or not we face the hard facts about what we are doing and why. The center piece of that conversation MUST be how to humanely and fairly and steadily REDUCE human populations downwards until we reach a level that works for people and for wild species and habitats, and that number is likely under 1 Billion.

    People freak out at this concept, but the world is fast approaching 8 Billion (2024) and 11.2 Billion by 2100. If you think we have problems now, hold onto your hats…it WILL get astronomically worse; technology will not be able to keep ahead of over-population demands, and high tech solutions mean high costs.

    Now, imagine instead that by 2020 (5 years from now), worldwide, countries say, okay, what would it look like if we had only 1/8th the number of people globally, and the world population steadily dropped to just 1 Billion…Now think about how many billions of acres would open up again for wild life, for re-established wetlands that provide vital breeding habitat for fish that humans eat, less total acres in farm land but far MORE farm land acres PER person! Food would be abundant and cheap and healthy, and land management would get so much easier because crop and grazing land rotations would be easy with all that extra land!

    Wild species would prosper and humans would have easy access for carefully managed use of those resources (for those who eat meat and cannot or do not want to eat vegetarian). Humans could go BACK to eating healthy, mostly wild, natural foods, with nature doing 95% of the production for us, for free!

    Housing would be cheap as land would become widely available for any person. People would have the choice to either live in densely packed (but much smaller footprint cities) OR, they could choose to live in suburban or rural areas, far less crowded than today’s suburban zones, and without the impacts since wild areas would run through and around all these smaller human living and farming areas. Recreation in gorgeous natural settings would be all around us! Nature would do most of the water storage for us, most of the cleaning and filtering, and most of the food production, for free.

    It would be heaven on earth. The main incentives for war and even the existence of greed is simply diminishing resources of all types due to human over-population. But if we humans, around the globe, STOPPED trying to OUTbreed the other “tribes”, then our numbers would drop, and land and resources would become widely available to all, and the greed would drop since anyone could have access to abundant resources, and wars would likely end, and nobody would see the need to even fund wars. Political and business corruption would be gutted to minimal levels.

    Open your eyes. What we have been doing has never worked. People have been exploited throughout history, largely due to over-population. It’s time to use our intelligence and to stop breeding like ignorant rabbits. Our religious institutions will NOT help us since most see breeding as a way to increase their religious tribe, and various cultures and nations may resist for the same reasons.

    But if we refuse to have this discussion, we will all die (or want to die) because there will be NO life on this earth, and if there is any human life remaining, it will be a living hell, with a few in control, the rest slaves, and no meaning to life except bare bones existence in a hellish, over-crowded earth devote of nature.

    1. I pretty much completely agree with your assessment of the problem of over-population.

      But until we have political, religious, or other leaders with enough guts to do something (which most people won’t want to do anyway), we are stuck with a short-sighted economic system based on continual growth and greed (not just corporate) and the unsustainable lust for more of everything. Our whole consumer society depends on that.

      I get very pessimistic.

  11. Let’s face it, the planet we live on can continue through geological time, but, overpopulation, greed, and lose of habitat, that is our natural resources, will destroy our place in the solar system.

    Too many people lead to hostilities, even more so with the threat of terrorism and lack of trust and understanding.Let alone greed.

    I hate urban sprawl. I hate seeing beautiful old neighborhoods destroyed for condos, etc.

    This is how I feel, especially surveying for housing developments through the years.

  12. Julie has it right and stated it very well. The planet is overpopulated and we are just rearranging the deck chairs on the Titanic as Paul Ehrlich said many years ago. Has anyone actually read Thomas Malthus? He stated the basic problem over 200 years ago. We ask our politicians to take away the pain of our own stupid greed and of course they do it. The result is ever greater stress on the environment.

  13. There are a lot of sacred cows in play with what you propose. Most prominently, real estate speculation, inflated values from that speculation, and the greed that fuels this process! We have seen millions of families and individuals lose not only their homes, but all equity in those homes from the bad actors who caused the bust of 2008. If you want to see a worst case scenario of chaotic overdevelopment, lack of zoning and the good ol’ boy corruption that enables this exploitation and damage to our environment (see Jeb Bush) then come on down to Florida and have a look! It is corporate profits above all else. Forgotten in this dreadful “growth” are ordinary working people as they get squeezed out of their neighborhoods in the gentrification process. Might be why a study quoted in the Tampa Bay Times yesterday showed Florida is 35th out of 50 states for “quality of life”. And our dreadful governor Herr Scott wonders why he can’t attract corporations to Florida? Who would want their employees suffering in that mediocre quality of life? I would like you to concentrate on the planning for affordable housing, albeit dense. Local governments need to ensure that in the mix are affordable homes, townhouses and condos for our $8 an hour workers! For a state with probably millions of these tourism and retail workers, there is a huge need here.

  14. Hi Rob-
    Your blog is right on. We need more urban infill to save our green spaces. I’m happy to write that here in Boston, the Fenway area is seeing a tremendous building boom. Residential towers are replacing single story fast-food joints surrounded by parking lots – all within easy walking distance to the Green Line trolley and commuter rail. See the projects here:

    http://boston.curbed.com/archives/2015/04/mapping-the-construction-around-fenway-park-on-opening-day.php#more

  15. The real environmental crisis is global over population. Until there is an open discussion and a concentrated effort to educate and assist people in limiting the number of children they have, all our efforts to save this planet are in vain!

  16. Rob, it’s also worth mentioning that denser housing typically uses much less water than single family homes on quarter acre or half acre lots. In Colorado, about half of our water use in the Denver area is for landscapes, mainly lawns. Throughout the arid West, including California with it’s current severe drought, planning and zoning that takes into account water use could be an important tool for maintaining healthy cities and healthy rivers.