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ChineseAnti-high-density development article in the LA Times
Today’s LA Times has a column by Ali Modarres, an urban geographer from the Pat Brown Institute of Cal State LA.
He argues that high density development will increase the urban heat-island effect, and is therefore worse for the environment.
This article outraged me because it’s a clear example of how science gets abused by policy makers. Or, in this case, policy-wonks. (This was the worst example I’ve seen since I read an article claiming that wind turbines would reduce the Sierra snowpack by reducing wind energy.)
The urban heat-island effect is real: As we pave over the natural landscape and replace it with asphalt, these surfaces retain and release heat from the sun. As a result, cities have higher temperatures than surrounding farmlands or parks.
The problem with this argument is that the urban heat-island effect sets in at fairly low levels of development. The alternative to LA’s high density movement is not a pastoral landscape or leafy suburbs: It’s Orange County, it’s Riverside, it’s the San Fernando Valley. These areas are already almost entirely developed, and the heat island effect is already extremely strong here.
The main point of the article seems to be that we need more open-space and energy efficiency to counter the heat-island effect. I have no argument with that (no, let me rephrase: I am in very strong agreement here). But I am very skeptical that you can meet either of these goals by opposing high-density development. The only alternative to high-density development is spawl. That or draconian population control.
To be fair, the author makes this point about the likely environmental benefits of high-density development in LA:
High-density development is usually considered environmentally friendly if it occurs near subway, rail or bus lines, and people can abandon their cars to get around. But unless people actually do take advantage of public transit and reduce their energy consumption, the environmental costs may outweigh the benefits.
He may be right about that. But under the sprawl-scenario, this isn’t even an option.
Discussion
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He’s right but he’s missing an important piece to this puzzle that we are not increasing our green space infrastructure to compliment it. We are tearing down parks for parking lots and then from parking lots to dense housing, but where’s the park that helps to keep this all in balance. Where are the street trees and parkways that are used to soften this problem and promote a reduction in urban heat island? In addition to the increase in parks maybe we can take a page from Curtiba Brazil (whom we already copied painting their buses) and see how desgined their additional park space to double as flood banks in case of those large sudden storms LA seems to get after a 2 year drought.
The key problem is that there’s never going to be a net increase in open space, from a heat-island perspective. You can open up new areas to recreation. But in terms of natural landscaping and green spaces, it’s a matter of stop-loss, almost never gain.
The only way to actually gain open space is through restoration. This is extremely expensive and nearly impossible on a large enough scale.
I correct myself. It’s possible to add in dense areas of LA, where you are replacing old land uses with new ones that incorporate more greenery. But preservation of current open space will always be more effective.
The urban heat-island effect is real: As we pave over the natural landscape and replace it with asphalt, these surfaces retain and release heat from the sun. As a result, cities have higher temperatures than surrounding farmlands or parks.
It isn’t just asphalt. It is everything urban including especially those aspects of high density patterns.
The problem with this argument is that the urban heat-island effect sets in at fairly low levels of development.
This is new and inovative. How low? The literature is sparse on this aspect. Your contribution is welcome. How low?
The alternative to LA’s high density movement is not a pastoral landscape or leafy suburbs: It’s Orange County, it’s Riverside, it’s the San Fernando Valley.
Densities for selected areas:
LA County: 2500
LA City: 8000
Orange County: 3600
San Fernando Valley: 6200
Quite a pastiche there.
The only alternative to high-density development is sp[r]awl.
There’s a lot more than that. There’s greenbelts, no development, offset mitigation, very low density, efficiency bonuses, nodalism, on and on.
But returning to your “only” alternative of Orange County. In 1965 Ventira and Orange Counties were statistically indistinguishable. You name it, they were very similar. Why isn’t Ventura County one of your alternatives?
Let’s keep OC, Ventura, SF Valley, Riveside as the SUBURBS and keep Los Angeles as the CITY. We should not copy suburbian to a city atmosphere.
I agree somewhat with the article about heat islands. We are developing these massive projects w/ massive parking (i.e. suburbian). The Ralph’s was built with a 120 space parking garage. Eventhough its right in the middle of downtown with great bus & taxi service. Parking garages are making cars too damn convenient. We’ve expanded out to the valleys to find “free parking”. I bet that’s all your friends # 1 arguement about not going into downtown. They don’t consider transit a viable alternative. As we keep building around metro rail, we should reduce the parking required per building b/c a sustainable/reliable alternative exists. Less cars coming into the city = better environment.
Rob, I don’t think that a threshold has been established. But people per unit acre (I’m assuming those are the units you’re using) isn’t relevant. Rather, we should look at % impervious surface, which is a good approximate for % paved area. Thresholds for hydrologic impacts (which are, admitttedly, not really comparable to climate impacts) are around 10% paved. You start screwing things up really quickly!
A 20-story condo and a 1-story ranch have similar impacts, in terms of the albedo affect, if their footprints are similar, but one will house far more people.
My point is that even though OC and LA (City) have different densities, the level of development is already high enough to have created urban heat islands. However, LA City supports more people for these equivalent impacts.
Why is Ventura different? Well, I assume that the Santa Monica Mountains helped retard sprawl in that direction, and instead sent it south to OC, which is within the LA Basin. But the pattern of development seen there (loss of farmland, growth of low density suburbs) is similar to what happened in OC 30 years ago.
True, Ventura has invested a bit more than OC in preserving its agricultural heritage.
Regarding those alternatives Rob mentions (granted I may be mistinterpretting what he’s referring to):
Greenbelts and nodes both require that density be increased in certain areas. They are both incompatible with the sprawlternative seen in OC and the IE.
No development, or maintaining low densities would certainly avoid incresaing the heat island effect. But population growth will continue here, and these solutions aren’t going to work. Plus, “low density” would have to be very low.
Efficiency bonuses: Great idea. But they don’t counter the heat island effect. Unless you are talking about things like rooftop gardening and more local climate-sensitive building mateirals.
Offset mitigation: I don’t think it’s poissble. Unless, again, you are talking about things like rooftop gardening.
I don’t think that a threshold has been established. But people per unit acre (I’m assuming those are the units you’re using) isn’t relevant.
Quite right. There hase been very little work on the the response curve. Climateaudit.org has essentially debunked the entire theory of anthropogenic global warming on that very point. My figures were persons/sq mi.
10% paved as a threshold isn’t enough information. My predialian manse is ~3000sf under roof and another 6000 sf in hardscape but I am on septic and my driveway is permeable and the patio is flagstone in sand. so despite my 30% paving ratio I have no runoff and significant groundwater recharge to my credit.
A 20-story condo and a 1-story ranch have similar impacts, in terms of the albedo affect, if their footprints are similar,
Exactly the opposite. The canyon effects from shading to reflection to thermal adsorption and reradiation all multiply the hirise’s impacts. Then there’s an interesting statistic. High rises use a higher percentage of suface area for roads than do the ranch tpypes your compare.
On to VenCo vs. OC. Yes, the Santa Monica Mountains were a help but that didn’t do much for the Antelope Valley despite their lousy weather, longer routes, bigger mountains now did it? I’m not being snotty, you really need to research why Ventura is different in outcome despite starting from exactly the same place.
Efficiency bonuses: Great idea. But they don’t counter the heat island effect.
Yes they do. That’s the point. And the amazing part is that most are so freaking low tech. Building codes in SoCal should insist upon 3 ft minimum roof overhangs and comensurate increases in spaces between structures. Multiple stories should also be “discouraged.” Lower density but also much lower energy intensity. Two little things. Now look at every new mass produced house you’ve seen in the last decade. 6 inch overhangs? Two stories? Ask why and then kill the planners that pushed for this.
According to the state demographers, the population of Ventura County in 1965 was 311,000, while the population of Orange County was about 1.1 million. [http://www.dof.ca.gov/HTML/DEMOGRAP/ReportsPapers/Estimates/E6/E6-47-69/documents/E-6CntyPopEstmts1947-1969.xls]
I think what Ali missed was alternatives. Okay, so big cities are heat islands. But what is the overall environmental impact of a less dense alternative (accommodating the same # of people in a different pattern, and in the aggregate is that better or worse?
2,000 square foot houses on 3,000 square foot lots, which is the current “sprawl” in Southern California, as seen in the Inland Empire and Antelope Valley, is not the answer though, and most of that is not planner driven, but rather market driven. I look at those tinder boxes they are building off I-15 on the way to Vegas and I wonder who would want to live there. You can’t say the Victorville or Hesperia city councils somehow decreed that was smart growth, either.
While twenty story steel and concrete buildings cause their own problems, moderate density townhomes and apartments (4-6 stories) combined with ample green spaces in between can soften the density. Thicker walls can help, because a lot of complaints about apartment living have to do with noisy neighbors. Much of the San Gabriel Valley and South Bay can be densified gracefully with row houses, and not with the crap apartment boxes of the 70’s or “detached condos” on 2,000 square foot “lots”.
I think the main problem is that Modarres blames high density planning for problems caused by most urban design. His proposed solutions (better efficiency and more open space) are 100% compatible with high-density, and very incompatible with sprawl.
Geez is anytime someone offers an alternative anti-?
Seriously, the guy offered several concrete suggestions in his editorial, and I don’t disagree. There’s this whole, have your cake and eat it too mentality in this country that is seriously hurting all aspects of our society.
There’s nothing wrong with recognizing the weaknesses in a policy and offering suggestions to improve it. That’s actually called good government.
All Ali is saying is, if you want high density development that doesn’t hurt the environment, accompany it with transit, walkable area, large open/park spaces, and green building codes.
Okay, great, let’s do it! Write the white papers, build the coalitions and make the public and private investments.
Building for the sake of building, without having any foresight into the long-term “side effects” is what got us into our current mess.
if you want high density development that doesn’t hurt the environment, accompany it with transit, walkable area, large open/park spaces, and green building codes.
Then it isn’t high density anymore is it?
Why couldn’t it be high density? Except for the green building codes, that pretty much describes Manhattan, and it’s one of the highest density areas in the United States.
Rob, your contributions to this blog have never been in as wildly inaccurate as post #12 above.
My response to the column will be published in the LA Times, probably on Monday. Yay!