Daily insights for city builders, delivered every morning at 6 AM ET. I’m Brandon Donnelly — a Toronto-based real estate developer and founder of Globizen. I’ve been writing here since 2013.
When I was in Phoenix this past spring I noticed a number of people carrying their big dogs around. At first I wasn’t sure what was going on. I thought maybe the dogs were injured and couldn’t walk. But then it dawned on me that maybe the ground was too hot for the dogs to walk on it. Phoenix is kind of hot sometimes and so this appears to be a thing.
In response to this kind of hot problem, the city has a pilot program underway where they’re testing out something that they are calling “cool pavement”, which is essentially a highly reflective coating that gets layered on top of your traditional asphalt streets. Here’s a video showing some of it getting applied:
The idea here is, of course, to lower the surface temperature during the day and also reduce the overall urban heat island. And after the first year of the pilot program, the results have been encouraging. Cool pavement had an average surface temperature that was 10.5 to 12 degrees Fahrenheit lower than traditional asphalt during the middle of the day.
But there have been some tradeoffs. Because of its higher reflectivity, mean radiant temperatures increased by about 5.5 degrees Fahrenheit during the day, which means that these streets feel warmer to humans when they’re around them. That’s obviously not ideal, but it could be a necessary trade-off to reduce surface temperatures across the city.
For more information on Phoenix’s cool pavement pilot program, click here.
This event poster has reminded me that, every now and then, I probably need to pull out a cooler headshot. In any event, next week I’m going to be a guest on SvNSpeaks, along with John Lorinc, talking about the obstacles that overly prescriptive and rigid development policies are creating for our climate goals. This is obviously a really important topic. Because if we were singularly focused on reducing carbon emissions, we wouldn’t be building the way we are building today.
For more information and to register for the virtual event, click here.
This past weekend I was reminded that Phoenix is largely what it is today — the 5th biggest city in the US — because of two very important things.
Firstly, the city had to figure out water supply.
About 50% of the city’s water supply comes from surface and groundwater, specifically the Verde River and the Salt River watersheds that are to the north and east of the city. And about 40% comes from the Central Arizona Project, which is a 541 km diversion canal that pulls water from the Colorado River and brings it through the state (terminating in Tucson). From what I have read, the CAP canal serves about 80% of the state’s population.
Secondly, Phoenix needed A/C.
Air conditioning was first invented at the beginning of the 1900s, but it really didn’t become ubiquitous until the second half of the century. And not surprisingly, it made the southwest of the US far more appealing. In 1950, Phoenix had just over 100,000 people. By 1960, the city had grown by about 311% to reach nearly 440,000 people. Apparently there was more construction in 1959 alone than from 1914 to 1945 combined. Air conditioning made Phoenix’s summers bearable.
Air conditioning is such an interesting topic because it’s one of those things that many of us take for granted. When you walk into a store or an office building in the summer, you expect it to be cool. But it hasn’t really been around all that long and its invention has, in many ways, been instrumental in defining the modern city. Even something as common and banal as a glass office tower with large floor plates would not be possible/practical without air conditioning.
We can certainly debate how sustainable it is to urbanize and air condition desert climates like Phoenix, but there’s no denying that air conditioning has had a profound impact on our urban landscapes. Diversion canals are pretty important too.
The typical way to measure carbon emissions is to think about it in terms of geography. You pick a particular place, such as a country or a city. You add up all the emissions that are taking place within its boundaries. And you’re then left with a territorial carbon footprint. If you’ve done any research on carbon emissions or climate change, you’ve likely encountered this method of accounting for carbon.
But there’s a flaw with this logic.
The problem with this method is that it considers each geography to being more or less independent. For example, let’s say you live in Philadelphia and you happen to be the owner of something called a computer. With territorial accounting, the carbon emissions associated with you powering your computer would get attributed to Philadelphia and the emissions associated with the actual production of the computer would get attributed to wherever it was made. Let’s say it was China.
One of the problems with this approach is that it penalizes the places that make a lot of stuff and it privileges the places that don’t make as much stuff, even if they may actually be the consumers of far more stuff. This might make you feel better about your life decisions if you happen to live in a dense urban knowledge economy that doesn’t really make anything physical — but is it entirely accurate?
An alternative measurement approach is consumption-based carbon accounting. The goal here is to capture all lifecycle emissions associated with a particular good or service, and then attribute it back to the consumer that arguably triggered the emissions. In the case of our Philadelphia computer example, the emissions associated with the production, transportation, and consumption of the computer would also get attributed locally to Philadelphia, instead of to China.
This more complex method of carbon accounting — which is something that the University of Pennsylvania has been working on over here (hence the Philadelphia computer example) — can be instructive for a whole host of reasons. It also has some relevance to city building.
It is widely understood that building up is more sustainable than building out. Because when you build out, you end up doing things like forcing people into cars. But the other side of this equation is that cities tend to also house a lot of rich people, and household wealth is a massive driver of carbon emissions when you account for them based on consumption. Some would argue it is more important than urban density.
In my opinion, none of this is to suggest that dense urban environments are bad. The point here is that territorial carbon emissions don’t fully capture the emissions caused by high consumers who might happen to live in an otherwise efficient urban environment. You can live in a compact apartment and walk to work, but what else are you consuming? And how might these consumption patterns change based on built form?
For more on this topic, check out this report by Daniel Cohen and Kevin Ummel (of the University of Pennsylvania) called, “The case for neighborhood-level carbon footprints.”
Living in a low-density place with lots of greenery and open space can feel like a pretty “green” way to live. Maybe you’ve even got a little garden where you grow delicious tomatoes. And indeed, a lot of people seem to think this is the case. According to this recent YouGov poll (which surveyed 1,000 Americans), 75% of US adult citizens believe that “it’s better for the environment if houses are built farther apart.” The number drops slightly to 68% for Democrats, but we’re still talking about a clear majority.
Most experts will tell you that the opposite is, in fact, true. One of the best ways to be green is to live in a high-density urban setting and get as far away as you can from the natural environment so that you don’t screw it up. There are multiple reasons for this, but it generally comes down to the fact that cities use land and other resources far more efficiently on a per capita basis. Smaller living spaces, fewer cars, more things that are shared, and so on.
The reason why this isn’t so obvious is that per capita thinking is perhaps harder to grasp. Living in the countryside certainly feels more green than living in the middle of New York City. But what if the 8.5 million or so people in New York City suddenly decided to sprawl outward into the countryside to consume more housing (that would then need to be heated and cooled), and then started driving everywhere (in lieu of taking transit, cycling, and walking)?
This would be a less green outcome. It’s about the collective here, not what feels nice and green for any one individual.
Last year, about 10% of all new motor vehicles registered in Canada were some form of electric vehicle (battery, hybrid, or plug-in EV). But this number is rising. And even though we’re still early on in the adoption curve, you can live a pretty great life with an electric vehicle today.
The caveats are perhaps as follows: (1) it really helps to have some kind of garage or driveway (so you can install a dedicated charging station) and (2) depending on your lifestyle, you may encounter the occasional feeling of “range anxiety.”
I drive to the mountains to go snowboarding every winter and my sense is that we need to get far more serious about blanketing our most densely populated regions with charging stations.
But here’s another problem that came up this week in conversation: How do you charge your EV if your only option for parking is on-street?
Do you have to run a cable from your home across the sidewalk? And then what happens if the spot in front, or nearby, isn’t available? Is it really going to be feasible/desirable to have charging stations on the sidewalks of every residential street when EV penetration reaches the majority?
This is clearly a problem that will need to be solved, and I know that many people and cities are working on it as we speak. I don’t know how advanced this is, but Norway, for instance, is working on wireless charging roads that power up vehicles from below.
What other possible solutions have you seen out there?
Gas prices are up. And here is a chart to support this statement:
If I were trying to be as sensational as possible, I would likely leave things here. But since that is generally not what I try and do with this blog, here is another chart showing gas prices over a longer time horizon.
Shown this way, gas prices don’t seem as crazy. In fact, we’re only now returning to where prices were back in 2008.
That said, these swings do impact things. And it is interesting to consider how these impacts might be felt differently across different cities.
So here is one more chart from City Observatory looking at the average number of miles driven per person prior to COVID:
One way to think about this chart is that it generally speaks to built form. Compact cities with higher densities and greater access to public transport, generally translates into people driving less.
The result is something that City Observatory refers to as a “green dividend.” Less driving, means you save money on cars and gas. And so when gas prices go up, so does your green dividend.
Of course, if you were to get really serious about calculating your green dividend, you’d also want to look at your housing costs, as land prices tend to decline as you sprawl outward.
Ultimately, this is a trade off between housing costs and transportation costs (both direct and indirect, such as the cost of your time).
But I think that there should be another dimension to this green dividend and that is the environmental benefits of less vehicle miles travelled. That too, of course, can be measured.
The UN’s Intergovernmental Panel on Climate Change (IPCC) has just published its latest climate change report. Available here. As a follow-up to this report, Dezeen spoke with Hélène Chartier of the sustainable urbanism network C40 Cities. And she makes some very good points about the importance of cities in combatting climate change.
In fact, she goes so far as to say that sustainable living is only really possible, at scale, in cities. Because to live a more sustainable lifestyle, you need the right kind of infrastructure in place. And to have the right kind of infrastructure in place, you need density.
This crucial point is often forgotten (though never on this blog). If you are truly concerned about climate change, then you should be for urban density. And if you are out there fighting against urban density, then your actions are undermining this global imperative.
Chartier rightly points out that “architects have a huge responsibility” when it comes to addressing climate change. And this is entirely true. Their job is the built environment. But with all due respect to architects, the problems that need solving are ultimately much broader. Architects can only do so much if they’re hamstrung by dumb land use policies and angry neighbors, among other things.
This needs to be a coordinated effort. We all have a huge responsibility.
I have long been interested in the possible relationships between climate and economy. Because my unproven hypothesis is that, given the choice, most city dwellers would probably prefer to hang out on Ipanema beach and drink caipirinhas in the sun than sit in a windowless cube farm toiling away on cover pages for TPS reports.
Well it turns out that there is some science to support this theory. A 2012 study by professors at Harvard and the University of North Carolina did in fact discover that people tend to work a little harder and focus a bit more when the weather is crappy outside and they’re not distracted by the promise of glorious sunshine.
This Scientific American article from 2013 also argued that there are physiological reasons for why we’re maybe not as sharp in extremely warm weather. The possible science is that excessive heat is more taxing on our body (compared to the cold) and so more energy is required to maintain homeostasis. That leaves less mental capacity for TPS cover pages.
Of course, these sorts of ideas aren’t all that novel. For centuries, economists as well as many others have posited that climate could be one of the reasons why geographies like northern Europe have historically had a higher standard of living than the south. It instilled work ethic and an awareness of deadlines. If you didn’t plan accordingly, you would starve to death in the winter.
But we also know that climate alone won’t do it. There are many examples of tropical cities with advanced economies and high-functioning societies. (The invention of air conditioning surely played a meaningful role.) And on the flipside, there are many examples of cold shitholes. So it’s complicated. But all this being said, doesn’t a caipirinha on the beach sound nice right about now?
At the beginning of this year, I predicted that we would see the price of carbon continue to rise, and in particular the price of EU carbon permits. Well the year is still young but so far the opposite has been happening. Back in January, the price of EU carbon permits were hovering around €80 per tonne. Since Russia bullied its way into Ukraine at the end of February, this market has corrected and now hovers around €66 per tonne. Generally carbon prices tend to increase alongside energy prices, but the opposite dynamic is happening right now because of all of this geopolitical uncertainty. But over the long-term, I don’t believe that this will remain true. So this feels like possible mispricing to me. Climate change may be a relatively less important issue in Europe right now, but it’s not going away.
