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A forthcoming collapse of the Atlantic meridional overturning circulation

nature.com

31–40 of 324 posts

Re: A forthcoming collapse of the Atlantic meridional overturning circulation

#31
post #7

An article from livescience.com that may be worth a read. TLDR: if slowdown occurs, temperatures could drop by 5C in Europe and North America. What a 5C drop actually looks like they don't say. https://www.livescience.com/planet-earth/climate-change/gulf...

I suppose that energy still has to go somewhere. Which place will warm up if Europe and North America cool down?

Obviously, the Atlantic Ocean closer to the equator.

Re: A forthcoming collapse of the Atlantic meridional overturning circulation

#32
I’m a physical oceanographer. While I have only skimmed this article I would like to make two quick comments.

1) The AMOC is one of the most studied parts of the world ocean and predictions about its collapse have been made since Stommel in 1961. I think in general any study on its imminent collapse should be taken with a grain of salt and it would be wise to wait for further replication and the consensus of the community. You can google AMOC collapse and find articles stretching back decades.

2) This may be my bias a dynamacist but I am skeptical of purely statistical models of AMOC collapse. The AMOC is complex and trying to predict the time of a complete collapse is a significant simplification (especially when, as the authors note, a slowdown rather than shutdown of the AMOC seems more likely from our current understanding).

Nevertheless this is a very interesting study and contribution to the field.

Edit: @abathur posted a wonderful link below that I wanted to spread further: https://www.sciencemediacentre.org/expert-reaction-to-paper-...

Re: A forthcoming collapse of the Atlantic meridional overturning circulation

#33
post #7

An article from livescience.com that may be worth a read. TLDR: if slowdown occurs, temperatures could drop by 5C in Europe and North America. What a 5C drop actually looks like they don't say. https://www.livescience.com/planet-earth/climate-change/gulf...

I suppose that energy still has to go somewhere. Which place will warm up if Europe and North America cool down?

Pretty sure Europe will heat up, NA will cool down. Currently the Atlantic current brings hot water from the equatorial zones up the US east coast, hence the humidity there. And it brings cool water down from the Arctic to Europe’s west coast, hence the mild non-humid climate there. Reversing the current would reverse that dynamic. It might make Europe less suitable to wine growing, for one, which requires mild cool climates.

Re: A forthcoming collapse of the Atlantic meridional overturning circulation

#35
Part of the challenge of this climate information is that it's so bloody complicated. Yes, Nature is doing a scientific write-up, but even reading the abstract all I get is "severe impacts on the climate in the North Atlantic region". What does that mean? Ok, well, why don't I at least look up the AMOC in the first place.

Quick dash over to wikipedia [1] and I find out that...

> The Atlantic meridional overturning circulation (AMOC) is part of a global thermohaline circulation in the oceans and is the zonally integrated component of surface and deep currents in the Atlantic Ocean.

While I am not a scientist, I consider myself fairly well-read and not an idiot. But when the first sentence of a Wikipedia article needs an ELI5 translation by ChatGPT... you know you're in for a reading adventure.

(But by the 3rd paragraph Wikipedia has a relatively understandable "what if this goes wrong" breakdown)

[1] https://en.wikipedia.org/wiki/Atlantic_meridional_overturnin...

Re: A forthcoming collapse of the Atlantic meridional overturning circulation

#36
post #19
post #11

Anyone else think that all these predictions are going to happen sooner rather than later in terms of the given prediction range? I can't help but think that a study focussing on a specific area like this one, antarctic sea ice, wildfire predictions etc must only be able to take so many variables into account and that second order effects, third order, fourth order and beyond from other climate subsystems are going t…

Yes. We're not sleepwalking to an uninhabitable dystopia, we're sprinting towards it. We may all be in for some serious problems in 5 to 10 years. I'm not a climate scientist, this is just an uninformed opinion, but everything I'm reading has me very worried.

What's happening right now could still be a very unlikely anomaly and everything may change back to "normal" soon. Or it isn't. Hard to judge for me, I'm not an expert.

Re: A forthcoming collapse of the Atlantic meridional overturning circulation

#37
post #19
post #11

Anyone else think that all these predictions are going to happen sooner rather than later in terms of the given prediction range? I can't help but think that a study focussing on a specific area like this one, antarctic sea ice, wildfire predictions etc must only be able to take so many variables into account and that second order effects, third order, fourth order and beyond from other climate subsystems are going t…

Yes. We're not sleepwalking to an uninhabitable dystopia, we're sprinting towards it. We may all be in for some serious problems in 5 to 10 years. I'm not a climate scientist, this is just an uninformed opinion, but everything I'm reading has me very worried.

Me, I am thinking it would be kind of similar to this series

https://en.wikipedia.org/wiki/Incorporated_(TV_series)

Majority of people will live in "dystopia lite", and top 1% and people they need ("slaves"?) will live in a better environment.

Re: A forthcoming collapse of the Atlantic meridional overturning circulation

#38
post #11

Anyone else think that all these predictions are going to happen sooner rather than later in terms of the given prediction range? I can't help but think that a study focussing on a specific area like this one, antarctic sea ice, wildfire predictions etc must only be able to take so many variables into account and that second order effects, third order, fourth order and beyond from other climate subsystems are going t…

> compound and significantly accelerate the timeline

There's a misconception that the biosphere is a delicate machine that will have a catastrophic internal failure if we don't follow the maintenance bibl^H^H^H^Hmanual, which apparently some experts have access to.

In reality, it is a highly dynamic, self-repairing living organism, which we are a part of. There are at least as many negative feedback loops as positive ones. And we should act to maintain our survival, but doomsaying is not part of that. Doomsaying and fearmongering is about power.

Re: A forthcoming collapse of the Atlantic meridional overturning circulation

#39
post #11

Anyone else think that all these predictions are going to happen sooner rather than later in terms of the given prediction range? I can't help but think that a study focussing on a specific area like this one, antarctic sea ice, wildfire predictions etc must only be able to take so many variables into account and that second order effects, third order, fourth order and beyond from other climate subsystems are going t…

Of course, things are always worse than the scientists say. That's why more science is needed. If it wasn't for them, we'd never even know about all the disasters.

Re: A forthcoming collapse of the Atlantic meridional overturning circulation

#40
post #7

An article from livescience.com that may be worth a read. TLDR: if slowdown occurs, temperatures could drop by 5C in Europe and North America. What a 5C drop actually looks like they don't say. https://www.livescience.com/planet-earth/climate-change/gulf...

So if this continues it will result in a 5C drop in temprature across North America and Europe? Am I understanding this correctly. Which for reference a 5C drop should mean that New York is covered in glacier according to this source https://xkcd.com/1732/

You've misunderstood the source. While temperatures locally will drop by 5C, the global average will not.

That chart shows global averages, ie, the whole world was 5C colder. NY might have been much, much colder than that.

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