• IWW4@lemmy.zip
    link
    fedilink
    arrow-up
    12
    arrow-down
    1
    ·
    edit-2
    15 days ago

    Every three years China pours more concrete than the US has since WWII.

    • Duamerthrax@lemmy.world
      link
      fedilink
      English
      arrow-up
      23
      arrow-down
      4
      ·
      15 days ago

      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
        ·
        15 days ago

        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
          ·
          14 days ago

          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
          ·
          14 days ago

          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
              ·
              14 days ago

              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
                  ·
                  14 days ago

                  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
              ·
              14 days ago

              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
        14 days ago

        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