AMOC appears closer to collapse. Previous analysis may be far too optimistic

https://www.cnn.com/2024/02/09/climate/atlantic-circulation-collapse-weather-climate/index.html

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I am sure that we will be told that those eggheads are just being worrywarts. I hear there is a pickleball tournament on the upper deck of the Titanic or do we just want to sit here and watch the icebergs float by?

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On what market duoes AMOC trade?

The Captain

“What the study doesn’t do, however, is give timeframes for a potential collapse.”

From the Van Westen paper:
“Natural variability dominates the AMOC strength in the first 400 years; however, after model year 800, a clear negative trend appears because of the increasing freshwater forcing. Then, after 1750 years of model integration, we find an abrupt AMOC collapse…”

So, even if we are not in the dominated by natural variability regime (not clear) we still have about 1000 years to play pickleball in Europe.

DB2

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All of them…

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Blindly heedlessly messing around with as insanely complicated a system as the Earth’s surface and atmosphere invites catastrophe from systems such as AMOC, and AMOC is extremely rare and special because we know it exists. I would be amazed if there are not at least ten other such systems that we do not have a clue about.

We are spinning the cylinder daily.

david fb

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I have no idea how you came up with this. According to this latest modeling a key indicator of when the AMOC collapse will occur is something called the freshwater transport (FovS). Below is a graph from the model showing that Freshwater transport declines as the time of AMOC collapse nears, at which point it reaches a minimum value (I put a big red arrow there). What follows is the rapid collapse of the current, indicated by the abrupt increase in FovS. That arrow is the tipping point.

Van Westen paper states that reanalysis data over the past 40 years shows “a robust and significant negative FovS trend (of −1.20 mSv year−1) over the past 40 years”, which they interpret as "This multi-reanalysis mean negative trend suggests that the AMOC is on course to tipping".

Data doesn’t say where we are on the timeline to collapse.

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A less snarky and perhaps more interesting answer is you can buy weather derivatives on the Chicago Mercantile Exchange.

“Energy companies, hedge funds and commodity traders are stepping up their use of financial products that let them bet on the weather, as they seek to protect themselves against - or profit from - the increasingly extreme global climate.”

“Futures prices closely follow the predictions of climate scientists, which, on average, appear to have materialised, thus validating the climate models. This close agreement between markets and models implies that traders are taking into consideration the scientific consensus on climate change when making trades.”

“Anyone doubting the observed warming trend can make a significant profit by betting against it in weather markets. However, the observed annual trend in futures prices shows that the supposedly efficient financial markets agree that climate is warming. When money is on the line, it is hard to find parties willing to bet against the scientific consensus.”

Let us know if you decide to bet against the scientific consensus.

https://www.reuters.com/markets/global-markets-weather-derivatives-analysis-pix-2023-10-11/

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Snark or Ignorance?

When you come across an unknown artifact in the wild, “AMOC,” what do you do? You try to figure out what it might be. In my environment the most common occurrence of four capital letters strung together happens to be on the NASDAQ marketplace. Google was no help. Yahoo was no help, Maybe a Fool might help.

Some Fools do use proper protocol, for example in this thread,

Others are less helpful, also from this thread,

Which didn’t gain you an ally in your war.

The Captain

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How did I come up with a long time-estimate? First off, there is no clear trend. For example, Parker and Ollier (1) found that by “using tide gauge data complementing recent satellite and ocean sensor observations, the stability of the AMOC is shown to go back to 1860.” (1) Even the Van Westen paper - with much shorter estimates - has both positive and negative historical FovS estimates (and the most negative one is actually increasing).

To me, this uncertainty means that we would still be in the first 800 years of their model, maybe even pre-400 year.

(1) Parker and Ollier
https://www.sciencedirect.com/science/article/pii/S246801331500008X

DB2

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I’d drop it into my favored search engine.

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These AMOC scenarios involve tremendously large amounts of added fresh water.

Most simulations of a shutdown involve adding unrealistically large quantities of fresh water all at once. And in some recent simulations with more advanced models, no shutdown has occurred, leading some to doubt whether this is a potential tipping point at all

Unlike in previous simulations, the [van Westen] team added fresh water gradually, rather than in one go… the researchers had to run the model for 2500 years. And they had to add a huge amount of freshwater – less than in previous simulations, but still around 80 times more than is currently entering the ocean as Greenland’s ice sheet melts. “So that is absurd and not very realistic,” says van Westen.

DB2

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I have a friend who was hired as the HR director for a new proto-ESG investment firm waaaay back in 1992. She absurdly thought of me as a smart investor and wanted me to educate her on what investment is all about (she had previously been #2 at a big MIC [military industrial complex] firm). What she and I concluded was that

  1. socially aware investing was a terrific advertising concept
  2. to make it work you needed to take advantage of that particular moment in time.
  3. that particular moment in time would not last much longer than a decade or two.

Gosh was I ever right! Now that ignorant lefty chatter is more fascinated by, uhm, Prezy Politics, ESG as anything other than an hysterical right wing talking point will vanish as fast as did big fins on cars when the Atlas rockets took over from the primitive early 1950’s Nike rockets and (more importantly) Buck Rogers. However, ESG investing had a good track record for quite awhile because stoooopid anti-ESG companies had some real problems as the turn of the Milennium took place.

Long time ago.

I am so disgusted by the stupidity of these sorts of sloganeering pseudo-policy mostly religious discussions.

d fb

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Is this in the wrong thread?

DB2

Yes. Sigh. 123r54=i84=5-0

d fb

Americans should expect the EU and possibly the UK to cut off a lot of air traffic. The EU will try harder to switch to a hydrogen economy. If planes can run on hydrogen travel will resume or won’t be shut down.

My family members have Irish citizenship. We will be able to fly probably into the EU regardless.

The EU will take this seriously and move on it hopefully in the next five to seven years. This election is tricky to balance who is in control versus climate needs. In the UK the conservatives are climate-friendly.

Capitalizing on the racism, ignorance and innumeracy of the American people has had a much better return than ESG.

intercst

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not losing money? :rofl:

The Captain

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Just want to add some context.

Climate is very complex and there are lots of limitations as to what models can do. The study in question took the best model available that could be used to run thousand year simulations and even then had to make a lot of simplifying assumptions. Supercomputing time can be expensive. The model is known to have biases and the simplifying assumptions include ignoring ongoing global warming trends. All these qualifications are stated prominently in the paper.

In light of these limitations, the authors asked three specific questions:

  1. Does the AMOC collapse with the gradual addition of fresh water.
  2. If so, is there a physical indication that such a collapse is near.
  3. What are the climatic consequences of such a collapse.

Note that the model limitations do not allow conclusions as to when a collapse will occur or even the likelihood of a collapse for any given amount of fresh water added.

The results with the most realistic model so far tested (with the above limitations) are that an AMOC collapse due to fresh water is possible, that there might be at least one signal that a collapse is near, and that the impact of an AMOC collapse will likely be global and sufficiently severe that adaptation in many locations will be very difficult.

The authors do not hide the facts that the model projections required very high amounts of fresh water and a couple of thousand years to see AMOC collapse. They also stated that it is likely that the biases in the model and the simplifying assumptions lead to overestimates of the fresh water needed and the time required. In other words, we don’t know how much fresh water from Greenland will cause a collapse nor do we know when such an event will happen. However, the proposed physical indicator suggests that the collapse may be closer than anticipated.

Some expert reaction to the study and its conclusions can be seen here: expert reaction to modelling study suggesting Atlantic Ocean circulation (AMOC) could be on course to collapse | Science Media Centre

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The risks of sooner have gone up.

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