Does anybody know if such a collapse would happen instantaneous or more gradual? With the massive amount of water in motion it feels like it would take a long time to stop, or are fluids behaving differently?

  • stravanasu
    link
    fedilink
    English
    arrow-up
    16
    ·
    edit-2
    1 year ago

    When I used to run simulations, a current of the size of the Gulf Stream could be turned on (with winds and Earth’s rotation), from nothing, in around 400 years (see p. 68). Then it maintained steadily. But turning off or changing in important ways can happen much faster. I’d like to know as well. There should be open-access articles in that journal about this.

  • alcyoneous@beehaw.org
    link
    fedilink
    arrow-up
    10
    ·
    1 year ago

    My understanding (and I’m not a scientist, I just have read a lot about this), is that there are two flow states of the AMOC. There is a fast state, and a slower state (which we are in now). It seems like it could just stop, but they don’t know for certain that it will ever completely stop. It will more likely just slow to a point where it is functionally dead. The current has already started to slow, so lots of people are trying to make predictive models about just how slowly it can go or when it will “collapse”.

    • Master@beehaw.org
      link
      fedilink
      arrow-up
      12
      ·
      1 year ago

      It’s not an on / off situation. It will gradually decline until it finally stops or reaches a critical threshold where it’s movement no longer significantly alters weather patterns. None of these climate change thresholds are as black and white as they are made out to be which is one of the argument tactics deniers use to argue against it. The reality is a slow decline until the affects are unrecoverable from.

        • CanadaPlus@lemmy.sdf.org
          link
          fedilink
          arrow-up
          1
          ·
          1 year ago

          But which are the stable states? I was under the impression if a wizard made climate change stop now it would go back to the fast state, since we probably haven’t hit the tipping point yet.

          • alcyoneous@beehaw.org
            link
            fedilink
            arrow-up
            1
            ·
            1 year ago

            I don’t think there really is a “stable” state that we can point to, just because it is always changing based on the climate conditions, and we have very imperfect data for talking about what it was like even a century ago. I’m also not certain that we haven’t hit a tipping point, from what I’ve read we’ve started to enter positive feedback loops climate wise, so the Earth would keep warming a bit and then stabilize to a warmer-than-it-should-be level even if we stopped polluting now. That would definitely continue to impact the currents.

            • CanadaPlus@lemmy.sdf.org
              link
              fedilink
              arrow-up
              1
              ·
              1 year ago

              Oh, okay. There’s other climate systems where it’s thought at least that we can point to distinct stable states. The Wikipedia article on tipping points has some examples.

              • alcyoneous@beehaw.org
                link
                fedilink
                arrow-up
                1
                ·
                1 year ago

                Ah cool, I’ll have to check that one out. I love a Wikipedia rabbit-hole but haven’t come across that one yet.