• Duamerthrax@lemmy.world
    link
    fedilink
    English
    arrow-up
    23
    arrow-down
    4
    ·
    1 个月前

    Just a reminder that concrete releases huge amounts of CO2 as it cures. Empty cities don’t help anyone.

    • grue@lemmy.world
      link
      fedilink
      arrow-up
      18
      arrow-down
      1
      ·
      1 个月前

      Another reason good urbanism and walkability is super important: the emissions don’t just come from the cars, they come from the excess roads themselves, too.

      • AA5B@lemmy.world
        link
        fedilink
        arrow-up
        1
        ·
        1 个月前

        It wasn’t even necessarily a bad idea given property growth, but it will be interesting to see what happens if they can’t stop population decline

      • Duamerthrax@lemmy.world
        link
        fedilink
        English
        arrow-up
        2
        arrow-down
        2
        ·
        1 个月前

        Their intention was to bolster the economy with busy work, but that’s not a long term solution.

          • Duamerthrax@lemmy.world
            link
            fedilink
            English
            arrow-up
            3
            arrow-down
            1
            ·
            1 个月前

            That’s comparing Apples to Shampoo. To completely different concepts and it’s not an either/or situation.

              • Duamerthrax@lemmy.world
                link
                fedilink
                English
                arrow-up
                1
                arrow-down
                1
                ·
                1 个月前

                Concrete doesn’t house CO2. When they created Biodome2, the engineers didn’t factor in the curing time and CO2 output and the scientists had to vent the facility or suffocate.

          • Bytemeister@lemmy.world
            link
            fedilink
            English
            arrow-up
            2
            arrow-down
            3
            ·
            1 个月前

            Houses don’t stand long on their own. It takes a significant amount of time and money to keep these things from filling up with mold or collapsing.

    • gandalf_der_12te@discuss.tchncs.de
      link
      fedilink
      arrow-up
      4
      ·
      edit-2
      1 个月前

      cement releases large amounts of CO2 when it is being produced, i.e. when the cement powder is being produced from limestone. this is due to a chemical reaction: CaCO3 (limestone) -> CaO (cement) + CO2

      later, when you mix the cement with water and sand to make concrete, it re-absorbs (approx. 43% of) that CO2. you’ve got it backwards :D

      curing reaction: CaO + CO2 -> CaCO3 (facilitated by water presence)


      edit: ok i looked it up and concrete only absorbs about 43% of the CO2 that is emitted during cement production. Source