Vegan meat June 15, 2012Posted by Cameron Shelley in : STV202 , comments closed
From the Huffington Post comes news of “Beyond meat”, a vegan meat startup funded by Evan Williams and Biz Stone, co-founders of Twitter. The aim of the company is to mass-produce meat substitutes based on plant tissues.
Why? For starters, Stone is a vegan and this venture will help to promote a vegan lifestyle for those who cannot live without their chicken tacos. Also, although the article does not pursue this matter, the meat-based diet popular in the Western world is not sustainable. Basically, turning edible plant matter into meat prior to human consumption is inefficient and creates associated externalities of waste and greenhouse gases. So, the hope is that producing “meat” directly from plant matter will address these issues that arise with the genuine article.
Does it taste like chicken? Reports suggest the new product is neither tasty nor offensive which, one would think, makes it perfect for processed food production.
Only one issue remains. What to call the fake meat? If it is going to sell, it needs some better branding and that starts with a good handle.
- The most obvious name would be “fake meat”. However, drawing attention to its fakeness seems like a bad idea. Who would eat margarine if it were called “imitation butter” (as Michael Pollan notes)? The same goes for mock meat, faux meat, and meat analogue!
- In some cases, I would suggest the term “mismeat”. This name conveys the happy thought, for meat eaters, that one might easily mistake the product for real meat. Of course, few fake meats rise to that standard, so the name might instead be construed as an admission that eating it instead of meat is a mistake.
- Another tactic is to call the fake meat “veggie-meat”, so that fake chicken would be called “veggie chicken”, for example. This nomenclature seems to work, and “veggie dogs” and “veggie burgers” have become common coinage in our household on those occasions when we eat the stuff.
- Stone seems to favor “vegan meat”. However, that name sounds too much like an oxymoron, like the proverbial “business ethics” or “airline food”.
The basic problem with all these names is that they concede the second-rate status of the material. A meat substitute remains an imitation of the real thing, not something to be sought out for its own sake. Instead, we need to Think different. Therefore, I suggest “iFood”!
What to do about food waste? April 18, 2012Posted by Cameron Shelley in : STV202 , comments closed
Depending on what source you believe, between one-third and one-half of food that comes out of the ground in the Western world goes unconsumed. There are various reasons for this phenomenon. One is simply entropy, that is, food simply leaks out of the system at various points, beginning with the farm. Another is that some of our fellow creatures, e.g., insects and mice, are at least as keen about our food as we are. Then, there is the fact that much of the food that Westerners purchase simply spoils before it is eaten. In fact, it is remarkable to note how much edible food is simply thrown away.
This inefficiency in the food system cries out for a response. Two responses have made the news of late. The first is a project by photographer Klaus Pichler to portray rotten food in a series of high-style photos. Disgusting old food never looked so good! Here’s a taste:
The point, Pichler says, is to encourage people to think harder about how they use food, and whether or not it is best regarded merely as a commodity. After all, although the photos depict rotten food in a new way, the subject matter itself should be familiar to most of us:
“If you go through the whole series, I think you’ll see more than one picture that you’ve experienced in your home,” he says.
A different response to the issue of food waste is presented in an article on edible food packaging. Some researchers regard edible packaging as the next big think in the packaging industry:
Leading the way (in publicity terms, at least) is the Dumbledore of food technology, Harvard wizard Dr David Edwards whose previous innovations include an “breathable” chocolate delightfully called Le Whif. He has now turned his attention to WikiCells – an edible membrane made from a biodegradable polymer and food particles – that can imitate “bottles” found in nature, such as grape skins.
So far, Dr Edwards and his team at Harvard’s Wyss Institute have created a tomato membrane containing gazpacho soup, an orange membrane filled with orange juice that can be sipped through a straw, a grape-like membrane holding wine and a chocolate membrane containing hot chocolate. He believes pretty much any flavour is possible.
There are many potential benefits to this research. Edible packaging should help to reduce the amount of waste that goes to the landfill or the recycling depot, for example. It might also help to reduce spoilage by helping to keep foods fresher for longer.
As always, there are potential difficulties with edible packaging. As the article notes, any packaging gets handled many times before the item within is used by the purchaser. Would you eat a package that has been passed along by perhaps dozens of unknown hands? Also, packaging is for advertising and not just for preservation. Thus, it may proliferate beyond the needs of food protection. Imagine what distributors or grocery stores would spray on to their produce if they could figure out how. The produce section would start to resemble the breakfast cereal isle, perhaps.
This last point reminds me somewhat of the invention of plastic bags for individual bananas by Del Monte Fresh Foods last year. Yes, each banana comes in its own plastic bag, re-labeled as “a natural energy snack on the go!” Jon Stewart derided the concept:
“What problem… what function does the bag serve that the peel does not currently serve? A product for people who love bananas but hate their biodegradability?”
In its defense, Del Monte claims that the bananas have been treated with Controlled Ripening Technology (CRT), which extends the shelf life of the banana for six days. This benefit can be realized only if the banana is confined to a plastic bag, however. This process increases the sustainability of the banana industry, apparently, although it requires the use of millions of little plastic bags whose environmental impact remains unclear.
In any event, the problem of food sustainability deserves our attention, and food packaging technology must play some role in our response to it.
Human prehistory and the paradox of specialization March 2, 2012Posted by Cameron Shelley in : STV202 , comments closed
A recent Discover magazine has an article on How we won the hominid wars. The article features a discussion with anthropologist Rick Potts, who talks about why modern humans persisted whereas Neandertals, Denisovans, Flores “Hobbits”, and other human types died out. In brief, his answer is that our ancestors were generalists whereas theirs were specialists. Being generalists is a better strategy for survival when environmental conditions begin to fluctuate.
This story provides an illustration of a general issue concerning sustainability. Sustainability refers to the length of time that an activity can endure. It is often equated with efficiency, or “bang for the buck.” This identification makes sense: If a process can be made more efficient, that is, be made to consume resources at a lesser rate, then it can endure longer while consuming those resources. There are some problems with this identification, as in the case of Jevons’ Paradox, previously discussed in this blog.
A related issue concerns adaptability. By this, I mean the facility for changing how a process is undertaken. A car could be considered adaptable, for example, if it can utilize different fuels. The Ford Model T, produced from 1908 until 1927, could run on ethanol, gasoline or kerosene. This was convenient for drivers who could not depend on the availability of any one fuel in general. However, such a generalized motor will not burn any one of those fuels as efficiently as a more specialized motor. As gasoline became more economical and widespread, it was adopted as the fuel of choice and automotive motors specialized in consuming it. I would not put kerosene in the tank of a Ford Focus!
So, although specialization permits greater efficiency and therefore sustainability in one way, it can put that sustainability at risk in another. Specialization locks the design in to the resource in question. If there were some sudden and major disruption in the supply of gasoline, for example, our current automotive fleet could not sustain our current transportation demands.
A similar issue may be seen in the biological world. The giant panda, for example, is a specialist:
An animal that shows a strong preference for one particular prey species and does not change its diet when the abundance of that species decreases, can be referred to as a specialist. While an animal with weak preferences for a prey species and one that frequently switches prey types is known as generalist.
The Giant panda relies exclusively on the stems of bamboo plants.
Specializing in the stems of bamboo plants has worked well for pandas in the sense that it has provided them with an abundant food supply and has allowed them to avoid competition with other herbivores (bamboo stems are not the easiest things to digest). However, specialization leaves the giant panda at risk of extinction in the event of a sudden and major disruption to their food supply.
So, back to the hominid wars. Why did the Neandertals go extinct? In part, it may be that they were physiologically specialized to cold weather and could not adapt to weather fluctuations that cropped up. Why did the Flores “hobbits” go extinct? In part, it may be that their specialized body form confined them to their small island home and left them unable to cope with some large change, perhaps the arrival of modern humans.
The tale of modern human beings then, may illustrate another paradox of efficiency and sustainability: The paradox of specialization. Specialization may increase efficiency and therefore sustainability in one way but also produces a lack of adaptability that may threaten sustainability in another way.
Stop worrying and love your robot car February 10, 2012Posted by Cameron Shelley in : STV202 , comments closed
Tom Vanderbilt, author of Traffic: Why we drive the way we do, has posted a piece on Wired responding to critics of autonomous or robot cars. Vanderbilt does not name the critics whom he rebuts, so it is difficult to tell if he represents them correctly and fairly. However, the points he makes seem sensible enough on their own merits.
(Alex Goy/Wikimedia Commons)
Two points, however, may present difficulties that do not receive adequate attention in his brief commentary. Let’s start with autonomy and privacy.
Vanderbilt notes that some people may object to robot cars because they would allow Big Brother, aka the government, to have a larger say in the behavior of your car. The point is, I gather, that some drivers enjoy illegal practices such as speeding, or drinking, texting, or watching TV while driving, and so on. A robot car would be programmed to obey all local rules and regulations, and would also be programmed to rat out occupants who break them. Of course, it might be worth pointing out that drinking, watching TV etc., might not be considered an offense in a robot car.
In defense of Vanderbilt’s anonymous critics, robot cars will raise issues with driving and traffic that simply do not exist with human drivers. The problem of managing accidents is one that has already been considered in this blog. Another would be the potential for increasing complexity of traffic regulation. Consider speed limits. Presently, speed limits tend to be fairly generic, with major highways having a default limit of 110 km/h (here in Ontario), county highways 80 or 90 km/h, and city streets 50 km/h. One could imagine matching speed limits much more precisely to local conditions. A single stretch of road could have dozens of speed limits at different points, depending on how straight they are, how narrow, how far from housing or schools, and so on. And then there are weather conditions to think about. The possibilities for regulation of autonomous cars may be nearly boundless. The introduction of autonomous cars will raise many new issues for governments and citizens to consider. My point is not that we should ban robot cars. It is just that a robot car is more than just a tool; it cannot be added to the existing traffic system without affecting that system in return. A similar story will apply to considerations of privacy.
Another point that Vanderbilt raises is whether or not autonomous cars will increase or decrease the amount of driving that occurs. Vanderbilt is skeptical that Jevons’ Paradox will apply. This is the argument that, since robot cars will likely be more fuel efficient that regular cars, that people will consume their savings by making more trips and at longer distances. As he implies, there is only so much time in the day, and people have other things they would likely prefer to do than sit in a car. So, this factor should limit any effect from the Paradox. However, as Vanderbilt concedes, the situation is not so simple. With the car driving itself, the driver’s attention is freed up for other tasks, such as sending and reading emails:
The utility of the commute could theoretically improve as people once stuck driving the car can now fire off e-mails with abandon. Then again, this increased utility might lead to more people taking advantage of the utility, thus leading to more traffic and more time spent in gridlock. At which point you might long for that other, essentially “self-driving” vehicle: the train.
In other words, the autonomous car will probably increase the productivity of each car trip for its occupants. Thus, the effective cost of the trip will decrease. It will be as if, along the lines of Jevons’ argument, you had added more time to the length of the day. In that case, people might well be willing to consume that “extra” time, while their car drives them places. In that event, fuel consumption could actually rise as a result of the introduction of robot cars.
As Vanderbilt says, neither of these observations provides a compelling reason to ban or abandon autonomous cars. However, neither should we think of the introduction of such cars as being just like the introduction of a new model year in an existing type.
Parking and progress February 2, 2012Posted by Cameron Shelley in : STV202 , comments closed
The New Scientist has an interesting item about a networked parking lot that makes parking more efficient. The basic idea is to have sensors in each space in a lot, which report their empty/full status to a central system. The information could then be presented to drivers through smartphone or in-car apps. As a result, the drivers could head right for an empty spot, instead of hunting around for one.
There are two reasons presented in favour of this scheme:
- Being able to find a spot right away would lessen frustration for drivers:
It’s a problem familiar to most of us: you circle for ages waiting to find a parking space and just when you’ve spotted one, someone else darts in first.
Most people do not enjoy parking lot driving (and I am one of them), so lessening its duration seems like win for sure.
- Lessening the time spent parking should lessen the pollution produced by cars idling while waiting for a space, or crawling slowly around the lot:
That means more emissions. According to a 2007 study by Donald Shoup at the University of California, Los Angeles, drivers in a 15-block district of LA notched up a staggering 1.5 billion kilometres a year looking for parking spaces. That’s the equivalent of 38 trips around the Earth, 178,000 litres of wasted gasoline and 662 tonnes of carbon dioxide.
That is a staggering statistic! It would be wonderful to eliminate the pollution generated by this useless activity.
The article does not consider any possible downsides, but there are some possibilities. First, as per Jevons’ Paradox, gains in efficiency can actually increase overall consumption. In this case, making parking more efficient may simply encourage more people to travel to parking lots more often. The result may be an increase in driving, and thus an increase in trips, travel time, and pollution. Traffic seems to be particularly vulnerable to such effects, so the problem cannot be easily dismissed.
Second, who is really benefiting from this efficiency? Drivers may benefit, if the effect of Jevons’ Paradox can somehow be avoided. However, the parties most likely to benefit are the establishments that use the parking lots. For example, the stores in a mall would likely do more business if people can be packed more efficiently into the parking lot. Right now, the possibility of a frustrating parking experience probably keeps some people away from the stores. If that frustration can be relieved, then more people will come to shop at the stores. That is a win for the store owners and their shareholders, not to mention the employees at the stores themselves.
The losers in this situation would be those who do not drive cars, either for lack of income or simply preference for transportation alternatives. If people with cars are more able to access stores through parking lots, then there is less incentive for cities to provide access to them through public transportation. Those citizens without cars will then have less opportunity to shop at the same establishments as their fellow citizens. That may or may not be a big problem, depending on what shopping or other service opportunities are at stake.
There are other possibilities for increased efficiency in access to resources that do not require high-tech gear or that invite more traffic. For example, the Brazilian city of Belo Horizonte has a program called Popular Basket in which busses travel around the city carrying basic food staples, acting as a kind of traveling farmer’s market. When the bus parks in your neighbourhood, you can pick up what you require. Instead of each family making a car trip to the mall, the mall comes within walking distance of every family in the neighbourhood. The scheme could cut down significantly on car travel while allowing neighbours to meet on occasion.
Of course, the scheme comes with trade-offs of its own: The buses tend to carry only basic goods, and are not always available. Furthermore, they might be viewed as beneath the dignity of some potential customers in North American cities. My point is simply that making parking lots more efficient is not necessarily the solution to our traffic woes, and that there are innovative alternatives to be considered if we look beyond our preference for shopping malls and high-tech gear.
Peer-to-peer sharing and design October 14, 2011Posted by Cameron Shelley in : STV202 , comments closed
The uptake of collaborative consumption (CC) seems to be progressing well. The basic idea of CC is that people can make money (or earn other rewards) by sharing their things with others, often through a Web-based interface. An established example would be Zipcar, a service that allows members to rent cars from a local pool on short notice and for short periods of time. Newer services, such as RelayRides, allow people to rent out their own vehicles to others on a short-term and ad hoc basis.
The point of such services is to allow people to squeeze more value from their gear. Your car, after all, probably does absolutely nothing for most of the time you own it. That is, it simply sits in your driveway or your parking spot depreciating. Why not exploit its potential through a rental arrangement? Another benefit of such schemes would be increasing sustainability of the vehicle fleet: All the trips that people want to make could be accomplished with a much small fleet of vehicles. So, the vehicle fleet on the road would be far more efficient and thus sustainable than it is currently.
A recent article in Atlantic Cities notes that GM has announced a plan to team up with RelayRides in order to make peer-to-peer rentals easier for owners to arrange. In brief, they plan to modify the OnStar system to make it easy for owners to sign up with services such as RelayRides.
This development raises a more general question: How might the design of gear be modified to make it easier to share it through peer-to-peer services? A cars become Internet objects, it makes sense to load them with software that would facilitate CC. In the near future, more of our stuff will join the Internet of things, so we can start thinking about how to integrate them with CC services. It might be useful to plan for sharing as part of the basic design process.
Books require only minor modifications to be shared via libraries. Today, that means RFID tags identifying books and their institutional owners. I suppose that my garden tools and patio furniture could be treated in much the same way. But how would you design a swimming pool, say, if you were planning to rent access to it to your neighbors?
Jevons’ Paradox and home energy use April 8, 2011Posted by Cameron Shelley in : STV202 , comments closed
A recent article from FastCompany points to another example of Jevons’ Paradox. In this case, a survey by the US Energy Information Administration suggests that the amount of energy consumed in American homes has remained constant from 1978 through 2005. This non-drop in consumption should be puzzling because of the substantial increase in appliance efficiency over that same time period. That is, furnaces, air conditioners, and major appliances have become much more efficient, which should result in a drop in energy usage.
The article blames the non-decrease on Jevons’ Paradox: the claim that increases in efficiency do not necessarily lead to drops in consumption because consumers simply find other ways to consume the resource. In this case, the slack in energy consumption due to home heating, cooling, etc., seems to have been taken up by an increase in electronic gadgets. That is, Americans have increased their usage of energy at home by increasing the number of TVs, computers, and so on, that they use there.
(Image courtesy of Milford via Wikimedia Commons.)
As Scott has pointed out earlier, the appearance of Jevons’ Paradox depends upon how consumption is accounted for. Water consumption in Waterloo region may decrease, for example, due to exporting water-using industries and not due to more efficient home water use. In the case of home energy use, an accounting issue may arise from the increase in average house size, as I have pointed out earlier:
The average new house floor area has gone from from 983 ft2 in 1950 to 2266 ft2 in 2000, while the amount of floor space per person has gone from 286 ft2 per capita in 1950 to 847 ft2 per capita in 2000.
This increase in average house size is due to a number of factors, perhaps including the increased efficiency in house construction, and the American penchant for home ownership and real estate speculation. So, you could argue that Jevons’ Paradox does not really apply here. After all, if home energy usage has remained constant while floor space per person has increased, then energy consumption per square foot has decreased vigorously over the years. So, Jevons’ Paradox appears if we measure energy consumption per household but disappears if we measure energy consumption per square foot. Why should we be more concerned with one measurement than the other?
From a purely mathematical standpoint, I do not see much difference. However, Jevons’ Paradox is not a mathematical claim but one about human nature. People do not necessarily respond to increased efficiency with lower consumption. So, we have to tune our accounting of the Paradox to units that matter to people. You could make a case that a per household measurement of energy usage makes more sense to people than a per area measurement because people are more affected by households than area. I would think that an even better move would be to look at home energy usage on a per capita basis. Per capita usage of energy has been steadily increasing, along with usage of many other things. At the same time, the number of persons living in each household has declined, going from 3.14 in 1970 to 2.62 in 1992, for example.
What to make of this? First, it seems that the application of Jevons’ Paradox is legitimate in this case: Home energy use per person is increasing, in spite of gains in efficiency of individual energy-using designs. Second, housing is becoming increasingly inefficient: Each square foot of housing is doing less and less work in being a home for individual persons. A traffic engineer faced with road system in which each kilometer is conveying fewer and fewer cars would probably suggest that we should close some lanes. If anything, the appearance of Jevons’ Paradox in home energy use suggests that we should make houses smaller or get more people into them. How can we do that?
Swedish drivers and Jevon’s Paradox March 23, 2011Posted by Cameron Shelley in : STV202 , comments closed
Scott has discussed the reduction in water usage in Waterloo region as a potential counterexample to Jevon’s Paradox. The paradox implies that gains in efficiency in a design do not necessarily translate into gains in sustainability. In the case of water usage, the implication would be that gains in water efficiency, e.g., from uptake of low-flow toilets, would not necessarily result in more sustainable water consumption. The recent drop in water consumption in the Waterloo region, coupled with uptake of low-flow toilets among other things, might call the Paradox into question.
Yet, Treehugger notes a recent study in Sweden that seems to confirm that the Paradox still has some teeth. Sweden has some of the most aggressive (and successful) sustainability policies around. It has, for example, been a world leader in the per capita uptake of “green” automobiles, such as cars that run on ethanol or clean diesel. So, Swedes are adopting more fuel-efficient cars, but does that mean that they are consuming less fuel (and producing less pollution) overall than before? Apparently not:
Emissions from the transport segment rose by 100,000 tons last year in Sweden. Trafikverket, the Swedish Tranport Agency (STA), reported that while purchases of efficient and greener cars decreased carbon dioxide emissions on a per car basis (from 164 to 151 grams of CO2 equivalent per kilometer driven), people’s increased driving caused emissions to rise.
It’s not easy being green! (Or perhaps it’s too easy.)
(Image courtesy of Stannered via Wikimedia Commons.)
As Scott mentioned, economists have tried to explain the paradox by appeal to rational behaviors, e.g., that overall economic growth in Sweden simply puts more money in Swedes’ pockets, allowing them to drive more. Well, economic growth in Sweden was positive in 2010, but negative overall in the 3-year study period.
Of course, the Paradox may spring from sources other than people’s rational responses to monetary incentives. For example, there is the effect of moral capital, which I have mentioned before. In an article entitled, Do green products make us better people?, Mazar and Zhong describe a study in which they set two groups of people to spend money in online stores. One store sold “green” products whereas the other sold conventional equivalents. After shopping, participants were given the opportunity to make extra money by cheating the experimenters. It turned out that people who bought products at the “green” store were more likely to cheat afterwards than the other group. Mazar and Zhong postulate that people have a sense of “moral capital”, that is, a sense of their moral rectitude. When people feel that they have a high level of moral capital, they may “spend” the excess by allowing themselves to behave badly. Perhaps this effect can help to explain the situation in Sweden: Swedes took to green cars, which gave them an elevated level of moral capital. They then spent the excess on themselves by taking more trips. The result was an overall increase in fuel consumption and pollution output.
Of course, this explanation is speculative. But it suggests that we may have to further into human nature than allowed in classical economics to understand patterns of consumption. As Scott noted, there is the effect of regulation to be considered. In addition, there is the fact that people are social animals and, as such, sometimes behave as they do out of a sense of guilt or license. So, perhaps the fault lies not in our cars but in ourselves.
How cities are not sustainable December 7, 2010Posted by Cameron Shelley in : STV202 , comments closed
A little while ago, I posted about why cities are green. Several commentators have noted that cities seem to allow people to live more sustainably than rural settlements allow them to. To make a long story short, cities offer efficiencies of economic and social opportunity for residents that rural areas do not offer so well. People respond with a lower birth rate and overall level of consumption.
(Image courtesy of Andreas Meck via Wikimedia Commons.)
It was also pointed out that the efficiencies provided by cities do not guarantee sustainability. As the British economist William Jevons pointed out, people sometimes respond to increased efficiencies by increasing their consumption, thus undoing or even reversing the advantages offered by the efficiency. Providing cheaper and more fuel-efficient cars, like the Tata Nano, for example, may actually increase the net rate of gasoline consumption by putting many more cars on the road and increasing the number of trips made by individual drivers.
Given this result, it is almost a wonder that increased efficiency in design would ever lead to increased sustainability of consumption, as it seems to do in cities. This got me to wondering how it might be that cities might be considered less sustainable than comparable rural areas. I do not have a comprehensive list at hand, but I would speculate that cities are less sustainable in the following ways:
- Caloric intake: The number of calories consumed by the average person in developed countries has climbed steadily over the years. In Canada, for example, the average calorie intake per person per day has increased from 2358 calories (1976) to 2788 calories (2002).
- House sizes have increased, even as family sizes have decreased. The average new house floor area has gone from from 983 ft2 in 1950 to 2266 ft2 in 2000, while the amount of floor space per person has gone from 286 ft2 per capita in 1950 to 847 ft2 per capita in 2000 (all figures from the United States).
- There is also the heat island effect, on which cities tend to be hotter than neighbouring rural areas.
So, as people have been increasingly living in cities, they have also been eating more, building larger houses (which they then have to furnish and heat), and been exposed to more heat, probably increasing heat stress and consumption of air conditioning. In these respects, Jevons seems to be vindicated: As people move into cities, they consume more resources per person. If cities are indeed more sustainable than rural settlements, as appears to be the case, then the social and economic factors driving down their net consumption must be powerful indeed!
Why cities are green November 15, 2010Posted by Cameron Shelley in : STV202 , comments closed
A recent FastCompany article summarizes why cities are more environmentally sustainable than rural populations. Although cities effect devastating changes to the land they are sited on, the residents of cities have a smaller environmental footprint, per person, than do their rural counterparts. Efficiency is the key.
Cities hold over half the world’s population, but only cover 3% of its surface. Density also lends itself to energy savings overall. A recent study found that the average London resident produced half the greenhouse gas emissions of the average Brit, and that the average New Yorker produced about a third of the emissions of the average American.
The compactness of cities and their infrastructure means that people’s social and economic activities can occur more efficiently than similar activities would in rural areas.
(Image courtesy of chensiyuan via Wikimedia Commons.)
Of course, it does not follow that because cities are more efficient than the alternative that they should create a more sustainable lifestyle. Increased efficiency can sometimes result in decreased sustainability, through a phenomenon called Jevon’s paradox. Basically, when a resource can be consumed more efficiently, more people may start to consume it, and consume it more voraciously, resulting in an overall increase in consumption. If this paradox applies to cities, then we might expect the growth of cities to touch off a spate of population growth and increasing consumption of resources per person. Why does this not happen?
Part of the answer, the article suggests, comes from social norms inculcated by city life, especially lowering the birth rate. Urban dwellers tend to have fewer children, on average, than do rural dwellers. The reason may be due, in part, to the economic and educational opportunities that city life affords to women. Basically, women find that there are other routes to fulfillment and prosperity than having a large family, and they come to prefer those options.
Also, in his recent book Whole Earth Discipline, Stewart Brand argues that cities are a hotbed of innovation, not just at the level of, say, the high-tech industry but also at the level of the slums where slum-dwellers make efficient use of the physical resources at hand and of their social network.
Roughly speaking, cities seem to allow people to fulfill their life goals, both in terms of material prosperity and social standing, in a way that requires less overall consumption than do rural settlements. This conclusion is not beyond dispute: City life imposes externalities on rural areas, e.g., pressure to adopt industrialized agriculture to feed the city’s population, that skew the assessment in favour of cities. However, a plausible case can be made that encouraging city living is a major step in the direction of an overall sustainable lifestyle. Importantly, it is not the mere efficiency of cities relative to rural settlements that supports this case. It is also the social rewards that cities provide that prevent their inhabitants from simply using the efficiency of cities to increase their overall consumption of the world’s resources.