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Honestly? That's just bullshit to try pushing people against A/C.
Cities are hotter than outside because:
- they absorb more heat :: concrete, asphalt absorb
Honestly? That's just bullshit to try pushing people against A/C.
Cities are hotter than outside because:
- they absorb more heat :: concrete, asphalt absorb much more than grass or trees and disperse far more slowly. Just go walking in a bush, measure temperature at 1.5 m from soil, do the same in grass covered area and the same over a road. You'll see and feel the difference;
- in cities there are MANY ICE vehicles whose engine produce much heat, much more than any electrical motor;
- in cities there is less air circulation than in the open nature due to the high and heat-absorbing buildings;
- in many cities glass coated skyscraper works like any other glass keeping much of Sun IR radiation inside.
These are the reason why cities are hotter. Another proof? They are ALSO hotter in winter, not just in summer. In winter you can count extra heat from badly insulated heated buildings, little cold pushed outside by the so far limited percentage of people heating with some heat pumps that have air on their exterior side, but look at the numbers and you'll see they are more hotter than mere heats spread outside by badly insulated heated buildings.
People should learn two things:
- cities WAS a necessity to evolve in the past, but with the '80 logistic revolution they lost one of their last reasons to exists, manufacturing became cheaper to do far from customers, so far from cities. With the remote work the last remaining reasons vanish as well. As a result dense cities and high rise buildings have NO REASONS TO EXISTS anymore. Try to keep them and sell them as green, good for the future etc is just a push toward intensive human farming to keep people dependent on service they don't own, living to operate them so they can pay them. Since in the modern era cities can't be sustained the push needs to makes people accept bad living condition as a new normal;
- we need to switch from a high density model, too dense for today state of tech and society, climate etc to a new less dense one, that's hard and that's means MANY will be simply "overflowing humans" to be put somewhere, since no one like that role, if told in such a crude way, some try to advertise such role with various "bells and whistles" but that's simply BULLSHIT.
If you try reasoning about the above you'll understand a thing: such move to put aside a significant percentage of humans can't really work, never worked in history. It does work if the set aside cohort is very limited, the poorest, very isolated and very dependent, but at modern scale can't work.
> we need to switch from a high density model, too dense for today state of tech and society, climate etc
The populations of dense cities use fewer resources than the same population spread out in low-density settlements, especially when those cities are laid out to be properly walkable. It's just basic economy of scale.
> in cities there are MANY ICE vehicles whose engine produce much heat, much more than any electrical motor;
In cities, not having a vehicle is an option. Outside of them, it's basically required in most places.
> It's just basic economy of scale.
Economies of scale aren't a goal on their own. Scaling something up will always have side effects... in the case of too dense urban areas, it's for example the sheer amount of traffic. For example, a quarter full of high-rises, no way you can get away without expensive high-capacity subterranian trains to handle commuters, and surface traffic is going to be a hot mess even with just shuttling the basic supplies for supermarkets, restaurants and the likes in one direction and waste on the other direction. In contrast, even a standard European mid-sized city can get away with cheap bus and tram lines. And it's harder to provide other essentials to meaningful life in a city as well, particularly where children are involved - land is too valuable to leave it as a park, and children can't have outdoor places to play either in kindergarten because it's too expensive, so you have even more traffic just from parents bringing their kids to kindergarten/school/playgrounds/whatnot.
Another effect of urban over-density that's often neglected is human health, both physical (we've seen that with COVID, just how fast pathogens can spread in urban areas) and mental. I mean, even here in Munich or Berlin we're not at the US levels of mental health and housing issues with people defecating on the sidewalk, but still it's noticeable how cities tend to have more anti-social behavior, as poverty and boredom are definitely contagious especially when not backed by the implicit social control that life even in smaller cities brings.
> Economies of scale aren't a goal on their own. Scaling something up will always have side effects... in the case of too dense urban areas, it's for example the sheer amount of traffic. For example, a quarter full of high-rises, no way you can get away without expensive high-capacity subterranian trains to handle commuters, and surface traffic is going to be a hot mess even with just shuttling the basic supplies for supermarkets, restaurants and the likes in one direction and waste on the other direction. In contrast, even a standard European mid-sized city can get away with cheap bus and tram lines.
But that high-capacity transit more than pays for itself (just the land value increase alone is more than the cost of building it). Yes there are costs to building densely (obviously to build a skyscraper at all costs more per square metre of floor space than building on the flat), but the end result is that more people can live (and more productively) for less total cost.
> Another effect of urban over-density that's often neglected is human health, both physical (we've seen that with COVID, just how fast pathogens can spread in urban areas) and mental. I mean, even here in Munich or Berlin we're not at the US levels of mental health and housing issues with people defecating on the sidewalk, but still it's noticeable how cities tend to have more anti-social behavior, as poverty and boredom are definitely contagious especially when not backed by the implicit social control that life even in smaller cities brings.
Do you have any evidence for that? The last results I've seen are that suburban living is significantly worse for mental health than dense urban cores (and I wouldn't be surprised if that was true for physical health as well), and frankly that fits with my experiences.
> The populations of dense cities use fewer resources than the same population spread out in low-density settlements, especially when those cities are laid out to be properly walkable. It's just basic economy of scale.
No, that's just marketing try to convince people of that...
> In cities, not having a vehicle is an option. Outside of them, it's basically required in most places.
Again that's marketing
Did you try to think hoe many resources are needed just to build high rise buildings compared to an equivalent set of single family homes? Hint: their own structure need to be supported, just that and foundations impose MUCH MORE resources than light homes. Similarly for any implant inside, including elevators.
Sewage network? Metros and so on?
A city if you try to count raw material use MUCH more than an equivalent spread area.
Not only: single family homes can evolve, they can be wood based and rebuild every let's say 50 years. Meaning they remain aligned to contemporary needs and tech, while rebuild a high rise building is a nightmare.
If you have modern homes with EV in most part of inhabited world, WFH for eligible jobs, not suburb USA style but mixed spread are where your dentist is just a small building few km away, there is a small supermarket few km away and so on you can have small-battery EV mostly recharge via domestic p.v. in cities you can walk, sure, unfortunately groceries are not made there, they came from far away, as far as more dense is the area because anybody eat, but in dense area there is no local food production. As a result you consume less, comfortably ignoring the logistic behind anything you use locally.
Now enlarge yourself talking about soil sealing who kill humus, water cycle alteration due to the big impact of such large and concentrated usage and discharge and so on.
If you REALLY try to dimension a city you'll easy see that anything you believe is false, marketing pushed because dense cities means dependency on services, witch means big business for very few on the shoulders of many. Try just to imaging ready-to-eat food delivery in a spread are: there is no chance Uber Eat, Just Eat and so one model keep up. People have kitchen, stockpile of food and time to do whatever they like, far less waste, far less packaging. Oh BTW this was an ancient known scam in Europe: in the past schools have internal kitchen, then they was told to externalize to make anything more efficient. As a result food quality have dropped, costs ans waste and packaging use skyrocketed.
> How do you figure that? Single family homes are inherently enormously costly - more concrete, more energy to heat or cool, and more roads to access them.
Single family homes can be wooden frame on light foundations, tall buildings can't. Single family homes can be demolished and rebuild every passage (meaning 50-80 years) so they can be as efficient as "relatively recent" tech allow, tall buildings are a nightmare to evolve. I'm Italian, having left years ago a typical large enough apartments in the north-west of the country for a home in Sweden of similar size. The some in Linköping use LESS energy than the old apartment. Now I'm living in the french Alps, a new wooden frame home, about twice the size of the old one and I consume FAR LESS. Evolvability matter, much.
Here I have an EV and domestic p.v. in an apartment I've had a garage, but no p.v. possible, also consuming space for a heat-pump water heater and for main heating is not that easy, in a home no issues.
Not only, in term of mere raw materials just grab a project of any high rise buildings and compare that with any single-family home project multiplied by the number of apartments: you'll easily see that the high rise building demand MUCH MORE materials than many homes.
> A dense city is the place where ebikes or golf carts are most practical
And they demand large supply chain as well, witch means highways, railways of a significant size, because people need to eat as well and they are many in a restricted area, enlarging even more the infra costs... Roads in a spread areas are lighter, do not demand much complex infra. Moving with light personal vehicles instead of moving heavy trucks, even if in smaller numbers, is FAR less consuming. The hard part is organize the logistics but with IT we can.
> Electrical transmission is extremely efficient, worrying about "local" electricity makes little sense. Metros in a city don't displace walking/cycling, they're displacing car use.
Electricity grids all over the world are LESS and LESS reliable due to growing demands, generation issues and climate change, there is NO WAY to keep them up reliably in a changing world, so the same for roads, rails, water supply and so on, that's why we talk about "resiliency", because modern countries, cities are damn fragile and inflexible.
> Low density cities/suburbs are the worst of both worlds for social life, IME.
beware US-style suburbs are horrific because they are residential only, you can't do anything else than stay at home or have a trip with a car. Mixed low density areas are another beast. Where I am now we are few homes spread in a dead-end road, but with a small park aside, few activities a 10' walking, a small lake a 12', a small river with enough water in the spring to canoe a bit on the north side and so on. It's far different than a big lot of homes and nothing else. So it's different the social life part: in large cities I normally not even know many if not most of my neighbors, here's families pass kids one to another normally, (almost) anyone cheers (almost) anyone else and casual parties in the garden are far common from spring to autumn. Something never seen in cities. At maximum there we go to a restaurant or a shopping center and so on.
> On average people in your position travel more, and in more environmentally damaging ways
In mere km-terms yes. In impacting terms no. I mean WFH I can recharge my EV almost on PV most of the time except winter. When I was in city I goes every weekends around, almost reaching the same kilometer range of now, but in more stressful way between traffic inside, highways and so on. Here I go calmly for beautiful roads. Roads that can be (some are, many are not) also full of small passages underneath to drain water and allow small animals to pass, having few small bridges to allow bigger animals to pass, cut the "forest" enough to obstacle eventual large fires to spread. No giant infra needed.
Keeping stuff to me means waste FAR LESS, well, because I'm attentive on what and how to keep. For instance means less packaging: I do not buy pre-cut cured meat under plastic, I buy entire hams, mortadella etc I cut in 2cm thick slices, freeze them, unfreeze one at a time, slicing them as thin as I wish. I do not buy bottles of wine but a couple of demijohns at a nearby producer, filling them with a pump, and i bottle them at home, with the same bottles every years. Similarly i buy olive oils in 10l batches filling the same bottles as needed. Of course I also eat salmon who happen to came from far away, so for shrimps, but some foods and beverage are local, and with far less packaging. Having more appliance if one breaks I'm not in a rush for another so potentially on scale the delivery of a new one and disposal of the old one can be scheduled for maximum efficiency. In case of a disaster the resulting emergency is far less "urgent" than in a city because most homes have a certain degree of autonomy and we are able to help ourselves and each others. So again, far less impacting.
It's not easy to dimension anything but try and i've no doubt you'll reach the same conclusions I've reached.