New study suggests the Atlantic overturning circulation "is on tipping course" | Hacker News Reader

New study suggests the Atlantic overturning circulation "is on tipping course"

realclimate.org

41 pointslamontcg14 comments

The study published today ("Physics-based early warning signal shows that AMOC is on tipping course"):

https://www.science.org/doi/10.1126/sciadv.adk1189

> They do not present a particular time period estimate for reaching the tipping point, as more observations of the ocean circulation at this latitude will be needed for that, but they note about last year’s Ditlevsen study that “their estimate of the tipping point (2025 to 2095, 95% confidence level) could be accurate.”

The Ditlevsen study ("Warning of a forthcoming collapse of the Atlantic meridional overturning circulation"): https://www.nature.com/articles/s41467-023-39810-w

Why are some articles on science.org (not this one) behind a paywall?

Doesn't make me happy but doom scrolling to "on the beach" with mass end of life pills, and the last submarine isn't going to help.

The impact is being debated. It's not going to be good but how bad has yet to be determined and may be judged in hindsight not in advance because the old "gulf stream keeps Britain warm" thing has been refined a lot in the last decade.

It's unlikely to be chocolates and rainbows. This write up suggests 1m of higher seas on the American side of the Atlantic is possible, presumably atmospheric pressure and loss of a stable outflow pattern. That's a lot of extra height for some places. Beyond current sea wall expectations maybe.

Does a 1m increase of the sea level on the American side equate to a a 1m drop on the European side?

Maybe we’ll finally get our land bridge to the UK back :).

Joking aside, a 1m drop around Denmark or the Netherlands would have significant consequences in the way the country looks.

I'm not an oceanographer but I suspect not. It's a fine question. The Dutch might get both more skating days on the canals (colder winters) and more sunburn (hotter summers) to compensate for the changes.

The referenced previous study (2023) was extensively discussed: https://news.ycombinator.com/item?id=36864319

Let’s say everyone in the world decides tomorrow it’s time to go to war with the climate crisis. Every leader in the world gave their full support and helped each other.

What would be step one?

start tracking all food, from crops to harvest, reduce family farms. Charge people to use carbon on a metered rate, slowly reducing the allowed amount each year. Keep everyone restricted with scarcity.

Well step one would depend on how you want to fight the war. It might be a Manhattan Project to build and launch a space parasol.

"Once we have a definite warning signal it will be too late to do anything about it, given the inertia in the system."

Do about it? I wonder what they have in mind exactly.

Government-led economic redirection on the scale of WWII is appropriate, given the threat.

However, at this time it seems much more likely that the ideologues will just drive us all into the ditch because they believe that their bunkers will work, and well, they have uncompromising ideologies.

And because they'll be dead before things get unbearable and impossible to hide.

Well yes. It is clear that it is possible to do something about it if we make a concerted effort to reduce our emissions. But we all collectively agree that sounds kind of annoying and would rather go out in a blaze of confusion and inaction.

[dupe]

Some more discussion: https://news.ycombinator.com/item?id=39319867

Reply on news.ycombinator.com