3 ms·

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

by 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.

by pyrale 7y ago

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.