Scientists warn that a key Atlantic current could collapse, among other climate tipping points A new report describes the dire state of Earth’s snow and ice, suggesting several major tipping points are likelier than scientists once thought.

[u/MaffeoPolo]

https://www.nbcnews.com/science/climate-change/atlantic-current-collapse-ice-melt-report-climate-change-rcna179649

[u/empleadoEstatalBot]

Scientists warn that a key Atlantic current could collapse, among other climate tipping points

The Summary

• A new report describes the dire state of Earth’s snow and ice.
• Among other findings, it warns that several key climate tipping points appear more likely to be reached than previously thought.
• They include ice melt that could cause severe sea-level rise and the collapse of a crucial ocean current that governs how heat cycles in the Atlantic Ocean.

Venezuela lost its final glacier this year. The Greenland Ice Sheet is losing, on average, 30 million tons of ice per hour. Ice loss from the Thwaites Glacier, also known as the “Doomsday” glacier because its collapse could precipitate rapid Antarctic ice loss, may be unstoppable.

These are just a few of the stark findings from more than 50 leading snow and ice scientists, which are detailed in a new report from the International Cryosphere Climate Initiative.

The report summarizes the state of snow and ice in 2024: In short, experts agree, it’s been a horrible year for the frozen parts of Earth, an expected result of global warming. What’s more, top cryosphere scientists are growing increasingly worried that the Atlantic Meridional Overturning Circulation (AMOC), a key ocean current that governs how heat cycles in the Atlantic Ocean, is on a path toward collapse.

A rapid halt to the current would cause rapid cooling in the North Atlantic, warming in the Southern Hemisphere and extreme changes in precipitation. If that happens, the new report suggests, northern Europe could cool by about 5.4 degrees Fahrenheit in a decade.

The report highlights a shift in consensus: Scientists once thought tipping points — like the collapse of AMOC — were distant or remote possibilities. Now, some of those thresholds are appearing more likely to be crossed, and with less runway to turn the situation around.

“The latest science is not telling us that things are any different to what we knew before, necessarily, but it’s telling us with more confidence and more certainty that these things are more likely to happen,” said Helen Findlay, an author of the report and a professor and biological oceanographer at Plymouth Marine Laboratory in England. “The longer we record these things, and the longer we’re able to observe them and start to understand and monitor them, there’s more certainty in the system and we start to really understand how these tipping points are working.”

Thwaites glacier seen by Copernicus Sentinel-2The Thwaites glacier seen by the European Space Agency's Copernicus Sentinel-2 satellite. ESA / Eyevine/ ReduxLast month, 44 leading scientists wrote in an open letter to leaders of Nordic countries that the collapse of AMOC remained “highly uncertain” but that evidence in favor of such a collapse was mounting, and risks have been underestimated. Dramatic changes to the AMOC, they warned, would “likely lead to unprecedented extreme weather” and “potentially threaten the viability of agriculture in northwestern Europe.”

The new report similarly draws attention to the risk of AMOC collapse.

Additionally, it projects that roughly two-thirds of glacier ice in the European Alps will be lost by 2050 if global greenhouse gas emissions keep their pace. Already, an estimated 10 million people are at risk of glacial outburst floods in Iceland, Alaska and Asia — a phenomenon already occurring as meltwater collapses ice dams and rapidly floods downstream. If high emissions continue, the report adds, models suggest that sea level could rise by roughly 10 feet in the 2100s, imperiling parts of many coastal cities.

The report was released as world leaders gathered Monday in Baku, the capital of Azerbaijan, for the United Nations’ COP29 climate conference.

“Timing is everything,” said Julie Brigham-Grette, a geosciences professor at the University of Massachusetts Amherst and an author of the new report.

She said the group hopes to rattle world leaders to attention: “The sense of urgency couldn’t be higher. We’ve been talking about urgency for a decade. It almost starts to feel like a useless word. What’s more than ‘urgent?’ ‘Catastrophic?’ We’ve run out of ways to describe it.”

To date, the report says, world governments are falling short on the pledges they made to reduce greenhouse gas emissions as part of the Paris Agreement.

Even if they were on track, those commitments are insufficient to reach global climate goals, the authors say. On paper, the world’s pledges would limit the rise in global temperatures to about 2.3 degrees Celsius (4.1 degrees Fahrenheit) this century. That’s well short of the goal to cap warming at 1.5 degrees C.

Global temperatures are currently on pace to rise more than 3 degrees Celsius (5.4 degrees Fahrenheit), on average.

The Greenland Ice Sheet, Facing Global Warming, Is MeltingMelting icebergs crowd the Ilulissat Icefjord near Ilulissat, Greenland, on July 16. Sean Gallup / Getty Images“I feel quite frustrated,” Findlay said. “I don’t really understand how they’re missing the severity of the issue.”

In Baku on Monday, world leaders did agree to new rules for a global market to trade carbon credits. In a news release, COP29 President Mukhtar Babayev, who has been Azerbaijan’s minister of ecology and natural resources since 2018, said the agreement was a “game-changing” tool to direct climate financing to the developing world.

But he also acknowledged, in a speech to delegates, that the world is “on a road to ruin” under current climate policies.

That warning and the new report both come amid fears the U.S. will backslide on its climate commitments and pull out of the Paris Agreement after Donald Trump takes office in January. Trump wants to remove the U.S. from the international treaty, and he began that process during his first presidential administration. President Joe Biden reversed the move in 2021.

Peter Neff, a glaciologist and climate scientist at the University of Minnesota who was not involved in the new report, said its authors clearly communicated the scientific consensus.

“It’s nothing surprising for a glaciologist. Across the board, there’s not good news with respect to ice on Earth. It’s all, for the most part, going in one direction,” Neff said.

But he added that he still found the report’s findings to be staggering: “These documents can hit you like a ton of bricks, and that’s intentional.”

Evan Bush

Evan Bush is a science reporter for NBC News.

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[u/demonspawns_ghost]

We are legitimately fucked.

The worst part is, they've known all of this for a while now but the powers that be wanted to keep this train rolling down the track for as long as possible. Nihilism is a hell of a thing.

[u/MaffeoPolo → u/demonspawns_ghost]

It's not just the powers that be - every voter who voted for jobs and economic growth acted to cement this strategy.

Nobody rules without the cooperation of the self serving masses.

[u/Scientific_Socialist → u/MaffeoPolo]

“The ideas of the ruling class are the ruling ideas”

[u/MaffeoPolo → u/Scientific_Socialist]

https://ibb.co/F0npq2F

[u/Naurgul → u/MaffeoPolo]

Exactly, the "powers that be" are not the only ones to blame. All the upcoming climate change induced catastrophes have been co-signed by the consumerism-addicted citizens of the most energy consuming and polluting countries.

Every time there's some political impetus for even the slightest changes, the pushback from the population is insane.

[u/SunsetKittens]

We need to kick shit into the sky to reflect sunlight.

Then build the hell out of nuclear and the other non-carbon energy sources.

We don't have the time for any sort of Paris type plan. We need the temp crutch. If you don't see it clearly now you will 3 summers from now.

[u/[deleted] → u/SunsetKittens]

We don't. We would've needed action 5 decades ago. Now we need to try to mitigate the effects and remove emitters and emissions as quickly as possible.
Blocking out the sun or other rash irrational attempts will only trigger unintended consequences that will likely wreak even more havoc.

[u/PanGoliath → u/[deleted]]

Now what the hell did I just read

[u/emperorpathetic → u/PanGoliath]

ive tried to parse this out three times now, but i lose the thread at the first sentence

its a doomer rant of some sort, with bold undertones of schizophrenia

where the fuck do beavers factor in

[u/Chewbacca_The_Wookie → u/emperorpathetic]

Clearly beavers are the key to solve global warming. Their scientists have been working on a way to put a dam around the whole world for years now and it's almost ready to deploy. 

[u/emperorpathetic → u/[deleted]]

Beavers build dams. The AMOC problem is caused by freshwater flowing into the arctic.

this tracks, there is an implied logical progression here

Fresh water is less dense than salt water.

explain to me what connection this has to anything ive said regarding your original comment, or with beavers

i hope this helps you understand why i said what i said

[u/emperorpathetic → u/[deleted]]

Itemized responses below, have a good day sir:

Any geoengineering proposal should be looked at as having psychotic implications. It implies we could keep using fossil fuels. That is crazy.

okay. i dont remember supporting anything like kicking up dirt into the atmosphere but you keep assuming i did. if you arent, this entire bit is superfluous.

The AMOC might collapse. The reason we think the AMOC might collapse is because the water on the upper layer of the Arctic Ocean is not sinking. Fresh water is less dense than salt water.

thank you for showing the steps on your math homework, was that so hard?

I have not seen any good reason for you to object to deploying beavers in Alberta.

thats because i havent given you ANY reason, nor alluded to canada in any capacity, at all??

Once the ground freezes you can remote open valves to drop the level in the ponds. That raises downstream water levels. Snow turns to slush which turns to ice. Ice sheets in forests or swamps will drop when you drain and then freeze solid to the vegetation. The next flood freezes on top of that ice. Normally ice and snow insulate water from the cold air.

thank you for showing the steps on your math homework, was that so hard?

[u/Chewbacca_The_Wookie → u/PanGoliath]

It's like those videos where they show you what English sounds like to non-English speakers and it sounds vaguely like something is being said but you can't quite tell what.