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That attitude drives me crazy. Each new high rise built in San Francisco prevents a few several blocks of nature being paved over for suburbs somewhere else. I

That attitude drives me crazy. Each new high rise built in San Francisco prevents a few several blocks of nature being paved over for suburbs somewhere else. I had this debate with an environmentalist who supported urban farming. Sure, urban farming is cool and a nice hobby, but it would be far more environmentally friendly to build a high rise. New high rises drive down the costs of urban living, more people move to the city, and whole tracts of nature are saved from destruction.

thorwasdfasdf 7y ago
> but it would be far more environmentally friendly to build a high rise. Absolutely Right! And, it would decrease pollution and global warming because people's commutes would be much much shorter, as they wouldn't be forced to commute from 80 miles away, like it currently is in the Bay Area.
- pyrale 7y ago
  Food and building material would still need to commute, and the amount of energy it represents probably can't be decreased enough to make dense cities a good thing for climate change.
  - bluGill 7y ago
    Food needs to be transported either way. Dense cities are better because the trucks need to make less stops on the delivery end.
    - pyrale 7y ago
      The number of stops is probably less important than the distance traveled by food. Towns or small cities can have food produces locally. In large cities, food has to travel across the city, and on top of that it has to travel across the space required for farming. This is a non-concern now of course, but in a world where we want to reduce transportation at scales serious enough to fight climate change, large cities will be a liability.
      - bluGill 7y ago
        Only if everybody is a subsistence farmer. If you want a modern lifestyle a large dense city is best: all the things you want from modern life are close and produced locally. The exceptions are food (food needs a lot of area to produce), and raw materials. These two are small enough that if they were our only use of transport (meaning you walk everywhere) they wouldn't affect climate change.
  - lostapathy 7y ago
    Building material "commuting" is a one time thing, not every day for the rest of your life like getting to work.
    - pyrale 7y ago
      What we can observe in large cities is that there is a constant stream of new buildings and construction works. The "build once" model works for one building and over one lifetime, but at the scale of a large city, construction work is a constant process.
pyrale 7y ago
Dense cities are not envoronmentally friendly. You have to go get food further, you have to use building materials that are a major cause of pollution, etc. Any large city needs tremendous amounts of energy to work, and we have not found clean and efficient sources of energy so far. Vertical farming could help big cities rely on less energy, but so far I don't see it being scaled to the extent we need.
- asdfman123 7y ago
  How much energy does it take to actually transport food into the cities from farmland? I remember reading that the amount of resources it takes is laughably small, especially when your lettuce is coming from the other side of the country anyway. But if you don't build in the city, you have to build outside of the city. Does it really take more resources to build a large housing complex than it takes to build an entire suburban neighborhood?
  - pyrale 7y ago
    A quick search gives me numbers around 10-15% of the total food energy. But if you remove processing, some of the packaging and some of the retail energy consumption, that are in large part consequences of not having access to fresh food, this number is much larger. The benefit of building smaller cities is that you can afford to have lettuce that comes from a couple kilometers away. If you build small cities, but still keep a distribution network that spans across continents, things will indeed not improve. Also you compare dense cities to (american?) suburbs. Dense cities are indeed better. My point is that they are a local optimum, and one that is not good enough to offset the effects of climate change. The model I would promote is cities small enough to rely on a short-distance farm network for most of their needs.
- iguy 7y ago
  Dense cities are energy-dense, for sure. But in energy used per person, they do very well. Apartments touching others on all sides are efficient to heat. Elevators are much more efficient transport than cars.

thorwasdfasdf 7y ago

> but it would be far more environmentally friendly to build a high rise. Absolutely Right! And, it would decrease pollution and global warming because people's commutes would be much much shorter, as they wouldn't be forced to commute from 80 miles away, like it currently is in the Bay Area.

pyrale 7y ago
Food and building material would still need to commute, and the amount of energy it represents probably can't be decreased enough to make dense cities a good thing for climate change.
- bluGill 7y ago
  Food needs to be transported either way. Dense cities are better because the trucks need to make less stops on the delivery end.
  - pyrale 7y ago
    The number of stops is probably less important than the distance traveled by food. Towns or small cities can have food produces locally. In large cities, food has to travel across the city, and on top of that it has to travel across the space required for farming. This is a non-concern now of course, but in a world where we want to reduce transportation at scales serious enough to fight climate change, large cities will be a liability.
    - bluGill 7y ago
      Only if everybody is a subsistence farmer. If you want a modern lifestyle a large dense city is best: all the things you want from modern life are close and produced locally. The exceptions are food (food needs a lot of area to produce), and raw materials. These two are small enough that if they were our only use of transport (meaning you walk everywhere) they wouldn't affect climate change.
- lostapathy 7y ago
  Building material "commuting" is a one time thing, not every day for the rest of your life like getting to work.
  - pyrale 7y ago
    What we can observe in large cities is that there is a constant stream of new buildings and construction works. The "build once" model works for one building and over one lifetime, but at the scale of a large city, construction work is a constant process.

pyrale 7y ago

Dense cities are not envoronmentally friendly. You have to go get food further, you have to use building materials that are a major cause of pollution, etc. Any large city needs tremendous amounts of energy to work, and we have not found clean and efficient sources of energy so far. Vertical farming could help big cities rely on less energy, but so far I don't see it being scaled to the extent we need.

asdfman123 7y ago
How much energy does it take to actually transport food into the cities from farmland? I remember reading that the amount of resources it takes is laughably small, especially when your lettuce is coming from the other side of the country anyway. But if you don't build in the city, you have to build outside of the city. Does it really take more resources to build a large housing complex than it takes to build an entire suburban neighborhood?
- pyrale 7y ago
  A quick search gives me numbers around 10-15% of the total food energy. But if you remove processing, some of the packaging and some of the retail energy consumption, that are in large part consequences of not having access to fresh food, this number is much larger. The benefit of building smaller cities is that you can afford to have lettuce that comes from a couple kilometers away. If you build small cities, but still keep a distribution network that spans across continents, things will indeed not improve. Also you compare dense cities to (american?) suburbs. Dense cities are indeed better. My point is that they are a local optimum, and one that is not good enough to offset the effects of climate change. The model I would promote is cities small enough to rely on a short-distance farm network for most of their needs.
iguy 7y ago
Dense cities are energy-dense, for sure. But in energy used per person, they do very well. Apartments touching others on all sides are efficient to heat. Elevators are much more efficient transport than cars.