Some people like to refer to concrete as cement. But that is technically incorrect. Cement is just one of the main ingredients in concrete, along with water and aggregates. So it's a bit like referring to a beer as a bottle of yeast.
That said, cement is pretty integral to concrete and it's largely the reason why the embodied carbon is so high in this widely-used building material. According to Brian Potter, cement production is responsible for somewhere between 5-10% of global CO2 emissions.
This is coming from the roughly 4.25 billion metric tons of cement that is produced annually and the 30 billion tons of concrete that it ends up in. The world likes concrete. And in particular, China likes concrete.
China alone is now producing about half of the world's cement. And since consumption generally tracks production, and the consumption of cement generally translates into concrete, China is using, by far, the most concrete.
I don't know what the right answer is to this particular carbon problem, but
Earlier this month, Vancouver City Council approved a plan that will have staff developing a "transport pricing" strategy for the city's core. (Transport pricing is just another term for road pricing or congestion pricing.) The plan is for staff to go away and work on this and then report back to Council with a pricing strategy sometime in 2022. At that point Council will look to approve the plan and it will all get implemented by 2025. Or at least that's the plan. I remain somewhat skeptical because Vancouver certainly isn't the first Canadian city to look at pricing its roads and congestion. Toronto has tried and failed. And so if Vancouver does end up doing this, they'll likely be the first city in the country.
So why are they doing this, or least trying to do this? Well, if you're a regular reader of this blog you'll know that I've been a supporter of road pricing for many years. Lots of old posts over here. But in the case of Vancouver, their stated goals are really as follows: 1) They want to reduce congestion and encourage people to use other forms of mobility; 2) they want to reduce carbon emissions by 50% by 2030; and 3) they want another revenue stream that can be used to fund things like transit and active transport. Put differently, it's about pricing/taxing the things that we want less of and then using that money to pay for the things we want more of.
Some people like to refer to concrete as cement. But that is technically incorrect. Cement is just one of the main ingredients in concrete, along with water and aggregates. So it's a bit like referring to a beer as a bottle of yeast.
That said, cement is pretty integral to concrete and it's largely the reason why the embodied carbon is so high in this widely-used building material. According to Brian Potter, cement production is responsible for somewhere between 5-10% of global CO2 emissions.
This is coming from the roughly 4.25 billion metric tons of cement that is produced annually and the 30 billion tons of concrete that it ends up in. The world likes concrete. And in particular, China likes concrete.
China alone is now producing about half of the world's cement. And since consumption generally tracks production, and the consumption of cement generally translates into concrete, China is using, by far, the most concrete.
I don't know what the right answer is to this particular carbon problem, but
Earlier this month, Vancouver City Council approved a plan that will have staff developing a "transport pricing" strategy for the city's core. (Transport pricing is just another term for road pricing or congestion pricing.) The plan is for staff to go away and work on this and then report back to Council with a pricing strategy sometime in 2022. At that point Council will look to approve the plan and it will all get implemented by 2025. Or at least that's the plan. I remain somewhat skeptical because Vancouver certainly isn't the first Canadian city to look at pricing its roads and congestion. Toronto has tried and failed. And so if Vancouver does end up doing this, they'll likely be the first city in the country.
So why are they doing this, or least trying to do this? Well, if you're a regular reader of this blog you'll know that I've been a supporter of road pricing for many years. Lots of old posts over here. But in the case of Vancouver, their stated goals are really as follows: 1) They want to reduce congestion and encourage people to use other forms of mobility; 2) they want to reduce carbon emissions by 50% by 2030; and 3) they want another revenue stream that can be used to fund things like transit and active transport. Put differently, it's about pricing/taxing the things that we want less of and then using that money to pay for the things we want more of.
Brandon Donnelly
Daily insights for city builders. Published since 2013 by Toronto-based real estate developer Brandon Donnelly.
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."
is perhaps a good place to start thinking about it. In it, he covers who is producing it, where it is being used, and how we might get to a world with less concrete.
Some of you might be wondering whether this is a good idea at a time when the centralizing pull of cities is being called into question. But I think it's important to keep in mind that Vancouver thinks it needs at least five years to implement its transport pricing. We'll be living through the roaring twenties by then. I am also a firm believer that cities are going to snap back significantly faster than most people think.
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."
is perhaps a good place to start thinking about it. In it, he covers who is producing it, where it is being used, and how we might get to a world with less concrete.
Some of you might be wondering whether this is a good idea at a time when the centralizing pull of cities is being called into question. But I think it's important to keep in mind that Vancouver thinks it needs at least five years to implement its transport pricing. We'll be living through the roaring twenties by then. I am also a firm believer that cities are going to snap back significantly faster than most people think.
