circulation ocean

disambig, see conveyor belt

-=-=

yt 10 26

Oct 13, 2026

Johan Rockström, Co-Founder, Planetary Guardians; Director, Potsdam Institute for Climate Impact Research, Germany 🇩🇪
H.E. Jóhann Páll Jóhannsson, Minister of the Environment, Energy, and Climate, Iceland 🇮🇸

Moderated by H.E. Katrín Jakobsdóttir, Chair of the Polar Dialogue, Senior Emissary, Arctic Circle; Prime Minister of Iceland 2017-2024 🇮🇸 Arctic Circle is the largest network of international dialogue and cooperation on the future of the Arctic. It is an open democratic platform with participation from governments, organisations, corporations, universities, think-tanks, environmental associations, indigenous communities, concerned citizens, and others interested in the development of the Arctic and its consequences for the future of the globe. It is a nonprofit and nonpartisan organisation.

AMOC Collapse: A National Security Threat?

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omfg

guk 6 26 Scientists warn Trump plan to axe US ocean monitoring system will leave world ‘flying blind’ | US news | The Guardian}:

Scientists warn Trump plan to axe US ocean monitoring system will leave world ‘flying blind’

Experts say dismantling the ocean observation system will ‘severely degrade’ the accuracy of weather predictions

Seascape: the state of our oceans is supported by

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About this content

Karen McVeigh

Fri 5 Jun 2026

The Trump administration’s plan to dismantle an ocean observation system vital to understanding the climate crisis and marine ecosystems would “severely degrade” the accuracy of weather predictions and El Niño forecasts, with economic consequences for the US, European and American scientists have warned.

Decommissioning the US system, which plays a major part in a global ocean observation network, would lead to a massive increase in error in the annual estimates of ocean heating rates, according to research published last month.

As a result, the forecasts and early warning systems for storms, tropical cyclones and El Niño would degrade, “sometimes dangerously so”, according to Sabrina Speich, an expert in global ocean monitoring at the Ecole Normale Supérieure (ENS) in Paris and chair of the ocean expert panel of the Global Climate Observing System.

The Ocean Observatories Initiative (OOI), run by the US National Science Foundation, is a vast network of seafloor systems, underwater gliders and moored surface platforms that feeds data to researchers, policymakers, educators and mariners worldwide. The initiative, which covers both US coastlines and extends into the North Atlantic and Southern Ocean, has been used to study marine heatwaves, harmful algal blooms, subduction zone earthquakes, ocean acidification and fisheries variability.

Dismantling it would remove a major component of the Global Ocean Observing System (GOOS), a network of robotic floats, moored buoys and research vessels experts describe as the “eyes and ears” of the ocean. The warning systems based on the data, “save lives”, experts say.

Prescient research published in Nature Climate Change last month showed how data losses in GOOS, a UN-coordinated framework for ocean data for weather and climate collected by several countries, could degrade the ocean heat estimates that underpin weather prediction, El Niño forecasting and fisheries management. Losing US observations would be worse than randomly losing 80% of all ocean data worldwide, it found. US-funded platforms span every ocean basin, plugging critical gaps that no other nation currently fills.

Speich, a co-author of the research, said: “Ocean heat content is the most robust indicator of climate change we have – not just of what is happening in the ocean, but of the entire climate system”. Vertical temperature profiles that provide ocean heat content, are “amongst the simplest measurements we can make”, she said.

“Lose them, and you lose your ability to track not just ocean warming but the climate system as a whole – they are a proxy for variables that become unavailable the moment the observations stop.

“Forecasts would continue – but they would degrade, sometimes dangerously so. Atmospheric observations alone are not sufficient” said Speich. “Ocean data [is] fundamental to early warning systems for tropical storms, cyclones and El Niño. And the consequences would not stop at science: the economic costs would be felt within the United States itself, from agriculture to insurance to disaster response.”

The loss of US observations, in a year predicted to be an El Niño year, with “supercharged” weather extremes, could also “lose the ability to see it coming clearly to act in time”, she said.

“The stakes are concrete: farmers in the US and across South America use El Niño forecasts to decide what to plant and when – whether to expect drought or flooding shapes every agricultural decision months in advance.”

The most recent El Niño, which hit in 2023-2024, was one of the five strongest on record and contributed to 2024’s record-breaking increase in global temperature.

Removing US observations alone would produce a 163% increase in error for annual ocean heating rates, the research by Speich and her co-authors found.

On Thursday, the European Union said it would boost its own monitoring of the world’s oceans by investing in a €92m ($107m) initiative called OceanEye, more than half of which will go to GOOS. The announcement, by the European Commission, was long-planned, not a direct response to the US move.

John P Abraham, professor of engineering at the University of St Thomas, in Minnesota, and co-author of the research paper, described the US administration’s move to dismantle the $368m OOI system as “penny-wise, pound foolish”.

“The US government wants to save less than a billion in sensors, which are the eyes and ears of the ocean” said Abraham. “We have hundreds of billions in climate costs per year. The cost of the observation system is a fraction of the climate costs from hurricanes and storms that hit the US. ”

The US suffered more than 400 climate and weather disasters where damages exceeded or reached $1bn,between 1980 and 2024. In 2024 alone, the costs of such disasters amounted to $177bn. This “billion dollar climate and weather product”, managed by the National Oceanic and Atmospheric Administration (Noaa) will no longer be updated due to “evolving priorities”, according to a note on its website.

The system, is, Abraham said is “quite an inexpensive way to reduce climate-related costs”.

“This is not about saving money, this is about killing climate science research,” Abraham said.

Samantha Burgess, the strategic climate lead at the Copernicus Climate Change Service (C3S), the European Union’s Earth observation system which integrates European space data with in-situ measurements to monitor changes and provide forecasts, said ocean observations are “irreplaceable” because “we can’t see the deep ocean from space.” They “save lives” by warning us of severe storms, she said.

Burgess said: “We need international cooperation to get the best available observations to mitigate risks in our changing world. Without ocean observations we are flying blind.”

A statement earlier this week by the National Science Foundation, which funds and oversees the OOI, said the program was not being cancelled entirely and described the plans as a “descope”, or reduction of elements, though it was not clear what data collection capacity would be left.

ref guk

The Trump administration plans to dismantle a $368m deep-sea observation system that has for more than a decade provided crucial data on ocean systems and climate change.

In a notice, the National Science Foundation (NSF) announced that it had “initiated descoping of the Ocean Observatories Initiative” (OOI), a vast ocean observation network comprising more than 900 instruments that collect data on ocean health, including current patterns, climate variability and marine biodiversity.

The notice, issued on 21 May, came just days after Trump fired all members of the independent board that oversees the NSF.

A statement by NSF head of media affairs, Mike England, said the program was not being cancelled entirely and described the plans as a “descope”, or reduction of elements, though it was not clear what data collection capacity would be left.

The NSF’s notice described plans to remove “all in-water infrastructure” from observation sites off the coasts of North Carolina, Oregon, Washington and Alaska, as well as from the Irminger Sea, a marginal sea between Greenland and Iceland.

Some scientists expressed dismay at the plan, while Democratic lawmakers said they would fight it, including Senator Chris Van Hollen of Maryland, who called it a “shortsighted move” that would “end up costing American taxpayers more not less”, the New York Times reported.

Senator Sheldon Whitehouse, a Rhode Island Democrat, said on X: “Fossil fuel is heating our oceans by the zettajoule, so Trump’s corrupt fossil fuel stooges want to turn off the monitors.”

Following the announcement, the OOI’s principal investigator, Jim Edson, said the NSF’s plan involves a phased recovery and infrastructure removal process expected to take place over the next 15 months. “As infrastructure is recovered from each array, the associated real-time data streams and observing capabilities at those locations will come to an end,” Edson said.

The move will bring to an end more than a decade of continuous ocean monitoring after the system first became operational in June 2016.

Describing the network as having “delivered the world’s most advanced continuously operating ocean observing systems”, Edson added: “We are profoundly grateful for the extraordinary efforts of the scientists, engineers, operators, educators, students and partners who made this facility possible and who continue to advance its legacy through the use of its data.”

The dismantling of the OOI marks another step in the Trump administration’s rollback of science and climate initiatives. It also follows Trump’s push to expand deep-sea mining and loosen fishing regulations, a policy that has alarmed ocean scientists and climate experts.

Hilary Palevsky, a professor focusing on marine biogeochemistry and oceanography at Boston College, pointed to the significance of the data that will be lost, particularly given the sophisticated engineering required to deploy and maintain the instruments.

“One of the real powers of this OOI and a lot of the collection of autonomous data is that scientists like me don’t have to have the expertise or the resources to be able to deploy this kind of infrastructure ourselves,” Palevsky said. “Being able to have instruments, both actually out in the atmosphere floating in the surface ocean, as well as surviving through the really deep mixing and waves in the subsurface.”

She said: “Over the more than 10 years that these things have been deployed, they’ve just gotten better and better at it. And so the data return has also gotten better and better over time … the scientific community was really just getting to the point of being able to capitalize on the data that had been collected so far … I’m really disappointed for the continuation of this important data set.”

Palevsky also warned that rebuilding such a network in the future would be difficult, saying: “If we want to put [the instruments] back out again, we need people who know how to do it and the team that knows how to do it is being dismantled along with the infrastructure program itself.

“We’re potentially at risk of having a gap in our ability to regain the expertise to do things that we had sort of just figured out how to pull off.”

For Palevsky and her students, OOI data has helped shed light on biological production in the ocean and its role in carbon sequestration – the process by which carbon dioxide is captured and stored – as well as deep-ocean processes, marine ecosystems and fisheries.

Data from the OOI has also contributed to research on the Atlantic Meridional Overturning Circulation (AMOC), a critical system of Atlantic Ocean currents that studies suggest may be more vulnerable to collapse than previously thought, with potentially severe consequences for the global climate.

“One of the important processes in the AMOC is what we call convection, this really deep mixing of surface waters into the deep ocean that happens in winter, basically driven by the surface ocean getting really cold because the atmosphere gets super cold in winter and big, windy storms blow across the surface ocean,” Palevsky said.

“We have gained some really important insights into both how that happens in the Irminger Sea in particular, and how the drivers of that process vary from year to year from the observations that have been gained at this site,” she added.

For scientists like Palevsky, the consequences of dismantling the OOI extend far beyond ocean researchers, particularly as climate change intensifies extreme weather events around the world.

“As we reduce the amount of data that we have, the observations, as well as the science more generally to understand what’s happening in the climate system, it makes it much harder for us as a society to understand what we’re facing and what we need to do to plan for and adapt to it,” she said.

In a statement to the Guardian, the NSF head of media affairs, Mike England, said the program was not being cancelled entirely: “The NSF is not cancelling the Ocean Observatories Initiative. The decision to descope aligns with NSF’s wider strategy of a nimbler approach to prioritize support for evolving scientific priorities and emerging technologies, as well as smart lifecycle management within its research infrastructure portfolio.”

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AN GRIST 11 25

Consider your morning cup of coffee. Your kettle’s heating element — or flame on a stove — warms up water that you infuse with beans and pour into a mug. Maybe you get busy and the cup of joe sits there for a while, releasing its heat into the atmosphere of the room, until it reaches equilibrium with the indoor temperature. In other words: It got cold.

*This story was originally published by Grist. Sign up for Grist's weekly newsletter here

Now consider that the expansive Southern Ocean, which wraps around Antarctica, could one day do much the same thing. Since the Industrial Revolution kicked off, humans have dialed up the kettle to its max, adding extraordinary amounts of heat into the atmosphere, more than 90 percent of which has been absorbed by the sea. (It’s also taken up a quarter of our CO2 emissions.) Under climate change, the Southern Ocean has been storing warmth which, like your morning jolt, can’t stay there forever, and will someday return to the atmosphere.

New modeling suggests that this “burp” of heat — the scientists called it that, by the way — could be abrupt. In a scenario where humanity eventually reduces its greenhouse gas emissions and then goes “net negative,” finding ways to remove those planet-warming pollutants from the atmosphere, global temperatures fall. But suddenly the Southern Ocean belches its accumulated heat, leading to a rate of planetary warming similar to what humanity is causing right now. And the thermal burping would continue for at least a century.

Put another way: According to this modeling, at least, humans figure out a way to reverse climate change, only to see the Southern Ocean essentially restart it. While there would be nothing our descendants could do to stop this — since the warming would be driven by already stored heat — the calculations are yet another urgent call to reduce that pollution as quickly and dramatically as possible.

This sudden eructation is not a sure thing, however — it’s the prediction of a model. But it’s a step toward understanding how the planet could respond as humans continue to manipulate the climate, both warming and cooling it. “The question is: How will the climate system, and specifically the ocean, react to scenarios where we remove CO2 from the atmosphere, and when we have a net global cooling effect?” said Svenja Frey, an oceanography PhD student at Germany’s GEOMAR Helmholtz Centre for Ocean Research Kiel and coauthor of the paper.

The Southern Ocean may encircle the frozen continent of Antarctica, but it’s very effective at storing heat: It alone holds around 80 percent of the warmth that’s taken up by all the oceans. Some of this comes from currents that transport relatively toasty waters south, but also lots of upwelling in the Southern Ocean brings cold water to the surface to be warmed up.

The skies above the Southern Ocean are also somewhat less reflective than elsewhere around the globe. Cargo ships and industries in the Northern Hemisphere spew air pollution in the form of aerosols, which themselves bounce solar energy back into the cosmos and help brighten clouds, which reflect still more. That cooling phenomenon has vied, in a sense, with the warming that’s come from the burning of fossil fuels. “That competition hasn’t been as prevalent over the Southern Hemisphere, because it’s this slightly more pristine atmosphere,” said Ric Williams, an ocean and climate scientist at the University of Liverpool, who studies the Southern Ocean but wasn’t involved in the paper.

In the scenario the researchers modeled, the atmospheric concentration of CO2 increases by 1 percent every year until the total amount is double what the planet had before the Industrial Revolution. Then negative emissions technologies reduce the carbon concentration by 0.1 percent annually. (The study didn’t look a specific techniques, but one option is direct air capture of CO2, though this remains expensive and limited in scale.) In response, the atmosphere, land, and oceans cool.

But something starts brewing in the Southern Ocean. Its surface becomes colder, but also saltier due to the formation of new sea ice: When sea water freezes, it rejects its salt, which is then absorbed into the surrounding waters and makes the surface layer heavier. “At the same time, we have these warm, deeper waters,” Frey said. “At some point, the water column becomes unstable, and that’s when we have the deep convection event.”

In other words, a burp. It’s just one way that our planet’s extraordinarily complex and intertwining systems might respond to rising and falling emissions in the centuries ahead. “There’s very large uncertainty in the Earth system response to net-negative emissions — we don’t understand that very well,” said Simon Fraser University climate scientist Kirsten Zickfeld, who studies these dynamics but wasn’t involved in the new paper. “We may well encounter surprises along the way, as this paper shows.”

To be clear, in this scenario, removing atmospheric carbon significantly reduces global temperatures, even factoring in the burp. And the faster we move away from fossil fuels, the less CO2 we’ll have to remove down the line. “Doing negative emissions and reducing our carbon load in the atmosphere is a good thing,” Williams said. “I would just add that, rather than do negative emissions, it’s better not to do the positive emissions in the first place.”

This article originally appeared in Grist at https://grist.org/oceans/hey-so-one-day-the-ocean-might-burp-up-a-bunch-of-heat/.

Grist is a nonprofit, independent media organization dedicated to telling stories of climate solutions and a just future. Learn more at Grist.org

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affects sharks CA

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maine timeline:

2003 (January) Scientist Robert Gagosian warns of the possibility of winters “twice as cold as the worst winters on record in the eastern United States in the past century” Scientist Robert Gagosian, president of the Woods Hole Oceanographic Institute, speaks to the World Economic Forum about the impact of climate change on the Ocean Conveyor, the deep circulation system that drives the world’s ocean currents and affects weather. Gagosian opens his report entitled, “Abrupt Climate Change: Should We Be Worried?” with the observation that “Most of the studies and debates on potential climate change, along with its ecological and economic impacts, have focused on the ongoing buildup of industrial greenhouse gases in the atmosphere and a gradual increase in global temperatures. This line of thinking, however, fails to consider another potentially disruptive climate scenario. It ignores recent and rapidly advancing evidence that Earth’s climate repeatedly has shifted abruptly and dramatically in the past, and is capable of doing so in the future.” Models predict, Gagosian reports, that with disruption of the Ocean Conveyor, the North Atlantic region would cool 3 to 5 degrees Celsius, producing winters “twice as cold as the worst winters on record in the eastern United States in the past century.” “It is important to clarify that we are not contemplating a situation of either abrupt cooling or global warming. Rather, abrupt regional cooling and gradual global warming can unfold simultaneously. Indeed, greenhouse warming is a destabilizing factor that makes abrupt climate change more probable.”*

*Robert Gagosian, “Abrupt Climate Change: Should We Be Worried?” Woods Hole Oceanographic Institute, January 27, 2003, http://www.whoi.edu/institutes/occi/images/WEFwhitepaper.pdf 2003 (January) Camille Parmesan and Gary Yohe publish the first formal assessment of

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https://science.howstuffworks.com/environmental/earth/oceanography/amoc-news.htm

Imagine a world where North America is locked in snow. Winter storms ravage Europe, while Australia bakes in permanent drought. This isn't just the plot of Roland Emmerich's 2004 disaster flick "The Day After Tomorrow." It's also what could happen if a crucial network of currents in the Atlantic Ocean were to shut down.

Unfortunately, research published Aug. 5, 2021 in Nature Climate Change suggests that these currents are weakening due to manmade climate change. And if nothing is done to prevent it, they may collapse completely.

The Pulse of the Ocean

The Atlantic Meridional Overturning Circulation, or AMOC, plays an essential role in regulating ocean temperatures. It is composed of a network of currents branching throughout the Atlantic Ocean like veins and arteries — some scientists compare it to the ocean's pulse.

The AMOC works like a perpetually turning conveyor belt. As water warms in the tropics, it "upwells," or rises to the surface, becoming more buoyant and less salty. This warm upwell rushes northward towards the polar regions, where it cools, becoming denser and saltier, before sinking once more. The cold, dense water is then whisked back to the tropics to start the cycle anew.

"The crucial ingredient is a positive feedback loop," says Niklas Boers, a researcher at the Potsdam Institute for Climate Impact Research in Germany. Salt water's density keeps the AMOC churning. However, "this also means that when large amounts of freshwater are added to the North Atlantic," Boers says, "the positive feedback might collapse."

Such an event is known as a "tipping point," a kind of ecological threshold that, once crossed, can take centuries or even millennia to stabilize. And evidence suggests that the tipping point is edging closer. In a 2019 report, the Intergovernmental Panel on Climate Change (IPCC) deemed the AMOC "very likely" to continue weakening under climate change.

The AMOC Run Amok

So, what would a world with a collapsed AMOC look like?

Since the AMOC has been "on" for all of recorded human history, it's difficult to say for sure. But Earth's ancient past offers some clues.

The last time the AMOC shut down was during a period known as the Younger Dryas, some 14,500 years ago. The most recent ice age was coming to an end; as temperatures rose, massive glacial melt off the North American landmass flooded into the Atlantic, disrupting the flow of oceanic currents. Then something strange happened: without a current to carry tropical waters to higher latitudes, the north polar warming trend reversed. The Northern Hemisphere was plunged into near-glacial conditions for the next 3,000 years.

If this were to happen again, Boers says, "we'll see much cooler temperatures in northern Europe." Certain regions could cool by as much as 14 degrees Fahrenheit (8 degrees Celsius). Unlike the Younger Dryas period, some of this freezing may be offset by global warming trends; however,AMOC collapse plus a warmer planet would permanently flood some cities along the United States' eastern seaboard.

In contrast, the Southern Hemisphere would experience even more warming, particularly around Antarctica. Many parts of Europe would also experience severe flooding and winter storms. "For Western Africa," Boers says, "it has been suggested that an AMOC collapse could lead to permanent drought conditions."

So, with that in mind, how close are we to "The Day After Tomorrow"?

A Real-life Disaster Movie?

Theoretically, the AMOC could be shut down by another massive influx of freshwater from a melted glacier the size of, say, Greenland. And the accelerated rate of glacial melt in that region does make this possibility alarming, to say the least.

That said, the effects wouldn't be as or as disaster movies portray. Many comprehensive climate models don't predict a total AMOC shut down for another 250-300 years under current emissions, though they predict a bevy of negative consequences as the currents slowly slide toward collapse.

Climate catastrophe is a slow-burn issue — but it's one that has a clear solution. "Avoid emitting greenhouse gases," says Boers. We live at a tipping point in Earth's history, one where our species faces a choice: We can either be the hero of the movie, or the disaster.

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cf al gore Inc truth

https://www.alternet.org/2021/08/gulf-stream-collapse/

no lnx pix twt

'Unimaginably catastrophic': Researchers fear Gulf Stream system could collapse

Jessica Corbett and Common Dreams August 05, 2021

While heatwaves, fires, and floods produce warnings that "we are living in a climate emergency, here and now," a scientific study suggested Thursday that a crucial Atlantic Ocean current system could collapse, which "would have severe impacts on the global climate system."

The study, published in the journal Nature Climate Change, focuses on the Atlantic Meridional Overturning Circulation (AMOC), which includes the Gulf Stream. As the United Kingdom's Met Office explains, it is "a large system of ocean currents that carry warm water from the tropics northwards into the North Atlantic," like a conveyor belt.

Previous research has shown AMOC weakening in recent centuries. The author of the new study, Niklas Boers of the Potsdam Institute of Climate Impact Research (PIK), found that this is likely related to a loss of stability.

"The Atlantic Meridional Overturning is one of our planet's key circulation systems," Boers, who is also affiliated with universities in the U.K. and Germany, said in a statement.

"We already know from some computer simulations and from data from Earth's past, so-called paleoclimate proxy records, that the AMOC can exhibit—in addition to the currently attained strong mode—an alternative, substantially weaker mode of operation," he continued."This bi-stability implies that abrupt transitions between the two circulation modes are in principle possible."

In the absence of long-term data on the current system's strength, Boers looked at its "fingerprints," sea-surface temperature and salinity patterns. He said that "a detailed analysis of these fingerprints in eight independent indices now suggests that the AMOC weakening during the last century is indeed likely to be associated with a loss of stability."

"The findings support the assessment that the AMOC decline is not just a fluctuation or a linear response to increasing temperatures," he continued, "but likely means the approaching of a critical threshold beyond which the circulation system could collapse."

As The Guardian's Damian Carrington reports, the collapse of "one of the planet's main potential tipping points"would be devastating on a global scale:

Such an event would have catastrophic consequences around the world, severely disrupting the rains that billions of people depend on for food in India, South America, and West Africa; increasing storms and lowering temperatures in Europe; and pushing up the sea level in the eastern U.S. It would also further endanger the Amazon rainforest and Antarctic ice sheets.

The complexity of the AMOC system and uncertainty over levels of future global heating make it impossible to forecast the date of any collapse for now. It could be within a decade or two, or several centuries away. But the colossal impact it would have means it must never be allowed to happen, the scientists said.

"The signs of destabilization being visible already is something that I wouldn't have expected and that I find scary," Boers told the newspaper. "It's something you just can't [allow to] happen."

It is unclear what level of global heating would cause a collapse, "so the only thing to do is keep emissions as low as possible," he added. "The likelihood of this extremely high-impact event happening increases with every gram of CO2 that we put into the atmosphere."

Some climate action advocates responded to the study by highlighting a science fiction movie that, as famed film critic Roger Ebert wrote nearly two decades ago, "is ridiculous, yes, but sublimely ridiculous—and the special effects are stupendous."

"We all laughed at The Day After Tomorrow, back in 2004," said Guy Shrubsole, policy and campaigns coordinator at Rewilding Britain. "Turned out it was a documentary."

The environmental advocacy group 350 Tacoma responded to the findings with a call to action.

"There are warning signs that the Gulf Stream could collapse, an unimaginably catastrophic (and irreversible) impact of fossil fuel-caused climate breakdown," the group tweeted. "Scientists say we cannot allow this to happen. People in power stand in our way."

The study comes ahead of a United Nations climate summit in Glasgow set to begin October 31. Last month, U.N. Secretary-General António Guterres noted the upcoming event and reminded leaders of wealthy countries that "the world urgently needs a clear and unambiguous commitment to the 1.5-degree goal of the Paris agreement," and "we are way off track."

The Day After Tomorrow - Official® Trailer [HD]

www.youtube.com

From melting ice caps to dying forests and thawing permafrost, the risk of ‘abrupt and irreversible changes’ is much higher than thought just a few years ago.

BY BOB BERWYN, INSIDECLIMATE NEWS

NOV 27, 2019

https://insideclimatenews.org/news/27112019/climate-tipping-points-permafrost-forests-ice-antarctica-greenland-amazon-nature

Humans are playing Russian roulette with Earth's climate by ignoring the growing risk of tipping points that, if passed, could jolt the climate system into "a new, less habitable 'hothouse' climate state," scientists are warning ahead of the annual UN climate summit.

Research now shows that there is a higher risk that "abrupt and irreversible changes" to the climate system could be triggered at smaller global temperature increases than thought just a few years ago. There are also indictations that exceeding tipping points in one system, such as the loss of Arctic sea ice, can increase the risk of crossing tipping points in others, a group of top scientists wrote Wednesday in the scientific journal Nature.

"What we're talking about is a point of no return, when we might actually lose control of this system, and there is a significant risk that we're going to do this," said Will Steffen, a climate researcher with the Australian National University and co-author of the commentary. "It's not going to be the same conditions with just a bit more heat or a bit more rainfall. It's a cascading process that gets out of control."

The scientists focused on nine parts of the climate system susceptible to tipping points, some of them interconnected:

Arctic sea ice, which is critical for reflecting the sun's energy back into space but is disappearing as the planet warms.
The Greenland Ice Sheet, which could raise sea level 20 feet if it melts.
:{Boreal forests, which would release morecarbon dioxide:(style="background-color:#ffff66ff"):}:(CO2) than they absorb:{ if they die and decay or burn.}:
Permafrost, which releases methane and other greenhouse gases as it thaws.
The Atlantic Meridional Overturning Circulation, a key ocean current, which would shift global weather patterns if it slowed down or stopped.
The Amazon rainforest, which could flip from a net absorber of greenhouse gases to a major emitter.
Warm-water corals, which will die on a large scale as the ocean warms, affecting commercial and subsistence fisheries.
The West Antarctic Ice Sheet, which would raise sea level by at least 10 feet if it melted entirely and is already threatened by warming from above and below.
Parts of the East Antarctic Ice Sheet that would also raise sea level significantly if they melted.

Just looking at Arctic changes shows how the links between parts of the climate system susceptible to tipping can amplify global warming and its effects, said Tim Lenton, director of the Global Systems Institute at Exeter University and an author of the commentary.

Shrinking sea ice increases ocean heat because it no longer reflects as much of the sun's energy back to space and it enables the darker water to absorb more warmth. The ocean heat extends over land and, combined with other heating effects, thaws permafrost, which releases more heat-trapping gases to the atmosphere, Lenton said.

Research shows that melting of the Greenland Ice Sheet may also be slowingtheAtlantic Meridional Overturning Circulation, a key Atlantic Ocean current that transports heat between the Northern and Southern Hemispheres and directs rainfall around the planet. That could disrupt monsoon rains critical to agriculture in developing countries.

"If you transfer less heat from south to north, it warms up the Southern Hemisphere, which affects the Antarctic ice sheets. When you start thinking about this, heading to a new climate state becomes very plausible indeed," he said.

The ocean circulation slowdown was documented in a 2015 study by researchers including Michael Mannand Stefan Rahmstorf, a co-author of the new commentary. Cold water from the melting Greenland Ice Sheet is likely slowing the current, showing "how these tipping point responses are actually interrelated, not independent,"Mann said. "If one goes early then so too may the others, like dominoes."

Lack of Policy Urgency as Permafrost Thaws

Despite increasingly urgent warnings about the effects of rising greenhouse gas emissions, two new reports published this week by the United Nations show that international efforts to slow global warming are falling far short of what scientists recommend.

The Emissions Gap Report—an annual assessment of global pledges to cut greenhouse gas emissions—shows that countries' current pledges under the Paris climate agreement will still raise global temperatures 3.2°C (5.8°F) by the end of the century, well beyond the Paris goal of limiting warming to well below 2°C (3.6°F). The Production Gap Report shows that the amount of oil, gas and coal that countries already plan to produce will lead to 50 percent more fossil fuels produced by 2030 than would be allowable to stay under 2°C warming.

The Earth is now warming faster and CO2 levels "are increasing at rates that are an order of magnitude higher than at the end of the last ice age," when rapid climate change destabilized the climate quickly, the scientists wrote in the Naturecommentary.

"To err on the side of danger is not a responsible option," they wrote.

long, cont....]

...The Western U.S. may already be seeing a forest dieback tipping point, Overpeck said.

"Much of our western forest cover is either dying or burning, leading to irreversible changes in vegetation that, in turn, impact water supplies and natural carbon storage," he said.

Some Tipping Points Are Already Close

One of the biggest concerns is that some tipping points, like the meltdown of alpine glaciers and near-total loss of coral reefs, will be reached even if the world meets the goals of the Paris climate agreement, said Katherine Richardson, a climate researcher at the University of Copenhagen and co-author of the commentary.

If multiple tipping points are reached, it's questionable whether emissions reductions will be enough to stabilize the climate system, she said.

"Another problem we have is that we have taken a cost-benefit approach," she said. "Economists assume high-impact tipping points are low probability events, but we may already have passed some of them—which completely changes the way we should be doing our cost-benefit analyses.

"In 2001, IPCC said not to worry (about tipping points) until there is 5 degrees Celsius warming, now they're saying 1 to 2 degrees. Economists have to stay on top of the science."

[map graf scary]

Richardson said she had just explained that morning to the Danish Parliament that some of the common tools for cutting emissions weren't proving to be effective enough, including the European Union's carbon trading marketat its current prices.

"There are so many emissions credits floating around that using them won't have any effect on total emissions or atmospheric concentrations on a meaningful time scale. We can't wait 30 to 40 years," she said. The UN Emissions Gap Report released this week "basically says we've done nothing so far."

The new Nature article reinforces other recent similar warnings, said climate scientist Katharine Hayhoe, director of the Texas Tech University Climate Science Center.That includes a chapter in thelatest U.S. National Climate Assessment on "potential surprises" in the climate system, "The scariest thing that you'll ever read that's not by Stephen King," Hayhoe said.

It explores climate impacts and feedback systems that we don't fully understand, she said, and "that may be far more worrisome than what we do know."

BAK no lnx graphics 1219

---

new 5/19 added upwelling (see sep disambig)

see heat transfer at bottom (mann, a million power plants, 5-10 degree drop vs 1 --> famine.

moderation?

---

Pompeo actually just cheered the ‘new opportunities’ presented by the Arctic’s melting ice sheets

by Cody Fenwick May 6, 2019

---

https://insideclimatenews.org/news/07052018/atlantic-ocean-circulation-slowing-climate-change-heat-temperature-rainfall-fish-why-you-should-care

scientists Say Ocean Circulation Is Slowing. Here’s Why You Should Care.

Hotter summers in Europe, changing rainfall in the tropics, hurricane risks along the U.S. coast: If Atlantic currents keep weakening, we'll feel it.

BY BOB BERWYN, INSIDECLIMATE NEWS

MAY 7, 2018

Scientists have found new evidence that the Atlantic Ocean's circulation has slowed by about 15 percent since the middle of the last century. If it continues to slow, that could have profound consequences for Earth's inhabitants.

Studies suggest it would mean much colder winters and hotter summers in Europe, changing rainfall patterns in the tropics, and warmer water building up along the U.S. coast that can fuel sea level rise and destructive storms. The changes in the North Atlantic could also intensify streams of icebergs into shipping lanes and coastal ice jams that hinder navigation.

There are already signs that the weakening is having an effect. In 2015, scientists traced the imminent collapse of the commercially important cod fishery in the region to rapidly warming water in the Gulf of Maine, which fits the pattern of slowing Atlantic circulation. Record-warm water off the East Coast that helped fuel 2011's destructive Hurricane Irene, as well as Superstorm Sandy a year later, appears to fit that pattern, as well, according to NASA.

So what exactly is going on here?, the Basics: What Is Ocean Circulation?

The oceans have thousands of currents, gyres and eddies that carry water around the planet. Their movements regulate the Earth's climate and transport carbon, heat and nutrients.

Together, these currents act like a giant conveyor belt that transports heat from the tropics to the higher latitudes. As warm water from the tropics flows toward the poles in wind-driven currents near the surface, it cools, becoming denser and heavier, and eventually sinks. It then begins flowing back toward the equator in a slow journey deep in the ocean.

Scientists call this the thermohaline circulation because it's driven by temperature and salinity.

Map: What Is the Thermohaline Circulation

"The ocean is the flywheel of the climate," said oceanographer Lisa Beal, with the University of Miami's Rosenstiel School of Marine and Atmospheric Science. "It sets the timing of climate change. It can do things like store heat in one place and release it somewhere else 1,000 years later."

What Happens If the Atlantic Circulation Slows?

In the Atlantic, the ocean conveyor belt is known as the Atlantic Meridional Overturning Circulation, or AMOC for short. The Gulf Stream, a wind-driven current that brings warm water northward along the U.S. coast, is a key part of it.

If the AMOC continues to weaken at the pace shown by the new research, it would affect temperatures and weather patterns in all countries bordering the Atlantic Ocean, as well in the ocean itself by changing rainfall patterns around the equator.

Europe could see much colder winters and hotter summers, according to a new study published in in the journal Paleoceanography and Paleoclimatology that also showed the potential for a weakening AMOC to cause abrupt climate shifts.

[vid]

Scientists aren't exactly sure how a weakening AMOC would affect Florida, the Gulf Coast and the rest of the U.S. East Coast, where the Gulf Stream influences temperatures, storm paths and rainfall, but there are some regional clues, including the warming ocean waters off New England.

Fisheries experts in the Northeast say continued weakening of the AMOC is expected to continue heating that area much faster than the average. That will "further impact fisheries and living marine resources in the region," said researcher Vincent Saba of NOAA's Northeast Fisheries Science Center.

The center's scientists say rising levels of CO2 in the atmosphere have affected the AMOC and slowed the redistribution of heat in the North Atlantic. Waters along the Northeast Continental Shelf have warmed, and the Gulf of Maine has warmed faster than 99 percent of the global ocean over the past 10 years, impacting the distribution of fish and other species and their prey.

[vid]

at the far southern end of the Atlantic, the circulation of deep, cold water near Antarctica may also be vulnerable to disruption, a recent study in the journal Science Advances suggests.

Those concerns were also reinforced by new research led by scientists at Germany's Potsdam Institute for Climate Impact Research who analyzed decades of ocean temperature data and found a weakening of the AMOC over time, particularly since the middle of the 20th century.

Scientists know the AMOC's strength fluctuates. For example, previous NASA research looking at much shorter periods of time found no change from 2002 to 2009.

But the new analysis of longer data sets, published in the journal Nature, shows weakening that's consistent with climate model projections of the ocean's response to warming caused by rising carbon dioxide levels. The U.S. Global Research Program warns the AMOC could weaken further by mid-century.

What's Causing Ocean Circulation to Slow?

After ruling out most other causes, scientists say an influx of cold, fresh water from melting Greenland ice is probably disrupting the ocean conveyor belt at a delicate point, where the cooled surface water starts sinking.

Fresh water pouring off the Greenland Ice Sheet and increased rainfall make the water less saline, and less dense than saltier water. That makes it harder to sink and drive the current's journey southward, explained Alexander Robinson of the University of Madrid, a co-author of the Nature study.

"If we do not rapidly stop global warming, we must expect a further long-term slowdown of the Atlantic overturning," Robinson said. "We are only beginning to understand the consequences of this unprecedented process—but they might be disruptive..

[vid]

satellite data above show Greenland losing mass as its ice melts. Credit: NASA

The same thing may be happening near Antarctica, according to University of Tasmania researcher Alessandro Silvano, who measured the freshening effect of melting glaciers.

"Our results suggest that increased glacial meltwater input in a warming climate will both reduce Antarctic Bottom Water formation and trigger increased mass loss from the Antarctic Ice Sheet, with consequences for the global overturning circulation and sea level rise," he concluded with co-authors in the Science Advances study.

There's also evidence that suggests changes in the ocean's circulation long ago were associated with extreme climate instability, including sharp and sudden surges in glaciation. Chemical tracers in ocean-bottom sediments show that link and also suggest that the AMOC is weaker now than at any time in at least the past 1,000 years.

Another study published in Nature last month describes changes starting about 150 years ago in the deep, cold current that heads southward from Greenland that suggests freshwater from ice melt at the end of the "Little Ice Age" may have had an impact. The researchers also found evidence that the AMOC has been weaker over the century and a half than in the previous 1,500 years.

We're seeing that kind of melting from Greenland again today as global temperatures rise. Some scientists are warning that serious climate change impacts could be more abrupt than expected, like rapid sea level rise of 20 feet within a century, or a sudden switch to drought-deluge cycles in California.

What Can Be Done About it?

The polar ice caps will continue to melt for centuries even if global greenhouse gas emissions stop immediately because of high levels of CO2 already built up in the atmosphere, so there's no realistic way to quickly stop changes to ocean circulation.

Atmospheric CO2 Levels Have Been Rising

The recent AMOC studies don't show what the long-term implications are, so it's uncertain if the circulation could stabilize at some new level if human-caused CO2 emissions are stopped, if the changes will gradually persist into the future, or if the oceans will pass a climate tipping point into some new, as-yet unknown state.

But understanding the effects can help people prepare. And if scientists can identify where circulation changes may cause oceans to warm exceptionally fast in coming decades, those areas could plan for storm potential and an extra measure of sea level rise that will happen as the oceans warm and expand.

Similarly, identifying how changes to ocean circulation affect adjacent land areas, with heat waves, droughts or flooding, would help communities develop more resilience to climate impacts.

Beyond the Atlantic

Other parts of the ocean circulation system are also changing as the planet warms, Beal said. That includes the Indian Ocean, where sea surface temperatures have warmed 1 degree Celsius since 1950 compared to the global average 0.6 degrees ocean warming.

"The heat gain in the Indian Ocean has been massive. In the last 20 years, the Indian Ocean has accounted of one-quarter of the total global ocean heat gain, and we don't know where this heat will end up," she said.

In that region, the circulation includes big gyres that are important heat transporters. Understanding of those systems is still scant, but the changes are already affecting millions of people in some of the world's most densely populated and poorest areas along the coasts of southern Asia. Sea level there is rising faster than the global average, increasing the chances of deadly heat waves and possibly altering the monsoon cycle.

[vid] animation above shows surface currents around the world. Credit: NASA]

In the wider Pacific Basin, surface currents spread heat from east to west. Overall, the circulation in the Pacific Ocean transports much more heat energy than the AMOC, making it important to understand how global warming will affect that system, as well, Beal said.

One such study in 2016 documented changes to major currents running along the eastern coasts of South Africa, Asia, Australia, and South America and found some of the currents were releasing 20 percent more heat than 50 years earlier, raising the risks of damaging storms along those coasts.

https://www.alternet.org/2019/12/new-iucn-report-on-ocean-oxygen-loss-gives-ultimate-wake-up-call-to-act-on-climate/

no lnx

New IUCN report on ocean oxygen loss gives ‘ultimate wake-up call’ to act on climate

Written by Andrea Germanos / Common Dreams December 8, 2019

Representing the expertise of over five dozens scientists across 17 countries, the report is framed as “the largest peer-reviewed study conducted so far on ocean deoxygenation.”

Infographic on deoxygenation from IUCN

A four-minute video entitled “A Breathless Ocean” released by the IUCN explains the process further:

The researchers found that from 1960-2010 overall ocean oxygen reserves fell by 2%, and they say the level could drop by as much as a further 7% by 2100.

That’s bad news, because changes in oxygen levels mess with species distribution. Species like jellyfish want low-oxygen areas, but low-oxygen sensitive ones, including most fish, don’t.

Those species are then driven to other areas not affected by deoxygenation, but that can leave them susceptible to over-fishing by commercial operations.

“To stop the worrying expansion of oxygen-poor areas,” said Laffoley, “we need to decisively curb greenhouse gas emissions as well as nutrient pollution from agriculture and other sources.”

That points to action global leaders must commit to right now as they attend COP 25.

---

palm oil indonesia burn peat soil carbon

...The connection matters because the Salim Group has benefited from more than $1.5 billion in loans and capital from foreign investors, including the American firms BlackRock and Vanguard, and Salim companies have pledged that their palm oil is not a product of recent deforestation or peatland destruction. Satellite images from 2017 confirmed that the forests on the Sintang plantations were now virtually gone. (A Salim Group executive, Mark Wakeford, declined to comment about the Sintang companies.)

UN report

World’s Emissions Gap Is Growing, with No Sign of Peaking Soon, UN Warns 11/19.

see 12/21 game over call: above

Climate Tipping Points Are Closer Than We Think, Scientists Warn

From melting ice caps to dying forests and thawing permafrost, the risk of ‘abrupt and irreversible changes’ is much higher than thought just a few years ago.

BY BOB BERWYN, INSIDECLIMATE NEWS

NOV 27, 2019

https://insideclimatenews.org/news/27112019/climate-tipping-points-permafrost-forests-ice-antarctica-greenland-amazon-nature

Research now shows that there is a higher risk that "abrupt and irreversible changes" to the climate system could be triggered at smaller global temperature increases than thought just a few years ago. There are also indictations that exceeding tipping points in one system, such as the loss of Arctic sea ice, can increase the risk of crossing tipping points in others, a group of top scientists wrote Wednesday in the scientific journal Nature.

The scientists focused on nine parts of the climate system susceptible to tipping points, some of them interconnected:

Arctic sea ice, which is critical for reflecting the sun's energy back into space but is disappearing as the planet warms.

The Greenland Ice Sheet, which could raise sea level 20 feet if it melts.

Boreal forests, which would release more carbon dioxide (CO2) than they absorb if they die and decay or burn.

Permafrost, which releases methane and other greenhouse gases as it thaws.

The Atlantic Meridional Overturning Circulation, a key ocean current, which would shift global weather patterns if it slowed down or stopped.

The Amazon rainforest, which could flip from a net absorber of greenhouse gases to a major emitter.

Warm-water corals, which will die on a large scale as the ocean warms, affecting commercial and subsistence fisheries.

The West Antarctic Ice Sheet, which would raise sea level by at least 10 feet if it melted entirely and is already threatened by warming from above and below.

Parts of the East Antarctic Ice Sheet that would also raise sea level significantly if they melted.

Research shows that melting of the Greenland Ice Sheet may also be slowing the Atlantic Meridional Overturning Circulation, a key Atlantic Ocean current that transports heat between the Northern and Southern Hemispheres and directs rainfall around the planet. That could disrupt monsoon rains critical to agriculture in developing countries.

The ocean circulation slowdown was documented in a 2015 study by researchers including Michael Mann and Stefan Rahmstorf, a co-author of the new commentary. Cold water from the melting Greenland Ice Sheet is likely slowing the current, showing "how these tipping point responses are actually interrelated, not independent,"Mann said. "If one goes early then so too may the others, like dominoes."

Lack of Policy Urgency as Permafrost Thaws

"To err on the side of danger is not a responsible option," they wrote.

long, cont....]

...The Western U.S. may already be seeing a forest dieback tipping point, Overpeck said.

"Much of our western forest cover is either dying or burning, leading to irreversible changes in vegetation that, in turn, impact water supplies and natural carbon storage," he said.

Some Tipping Points Are Already Close

If multiple tipping points are reached, it's questionable whether emissions reductions will be enough to stabilize the climate system, she said.

"In 2001, IPCC said not to worry (about tipping points) until there is 5 degrees Celsius warming, now they're saying 1 to 2 degrees. Economists have to stay on top of the science."

[map graf scary]

Richardson said she had just explained that morning to the Danish Parliament that some of the common tools for cutting emissions weren't proving to be effective enough, including the European Union's carbon trading market at its current prices.

The new Nature article reinforces other recent similar warnings, said climate scientist Katharine Hayhoe, director of the Texas Tech University Climate Science Center.That includes a chapter in the latest U.S. National Climate Assessment on "potential surprises" in the climate system, "The scariest thing that you'll ever read that's not by Stephen King," Hayhoe said.

It explores climate impacts and feedback systems that we don't fully understand, she said, and "that may be far more worrisome than what we do know."

---

gray whales

165 west coast, 90% do not strand/wash up; arctic krill b/c AGW

omg (whales starve off CA no food)

Pompeo actually just cheered the ‘new opportunities’ presented by the Arctic’s melting ice sheets

---

519 the conv

...It is much more challenging to quantify the carbon dioxide stored in ocean reservoirs. Vast regions of the seafloor contain sites of active volcanism and hydrothermal venting, but scientists know virtually nothing about how much carbon dioxide is accumulating in surrounding rocks and sediments. In my view, there is an urgent need to study marine settings where carbon dioxide is likely accumulating, and then to assess how susceptible they may be to destabilization.Carbon dioxide is also venting around Mammoth Mountain, California, at spots where magma rises through Earth’s crust and stalls at shallow depths. High concentrations of carbon dioxide in the soil have killed more than 100 acres of trees. Scientists are working to identify and characterize other sites on land where such releases could occur.

Warming oceans, increasing risk

This is not an endeavor that should be deferred. Earth’s oceans are warming rapidly, and climate models project that they will warm fastest near the poles, where deep currents form that carry warming waters downward from the surface.

As these warm waters sink into the ocean’s interior, they transport excess heat towards sites where carbon dioxide reservoirs can form. Those warmer waters will eventually destabilize the hydrate seals that keep liquid carbon dioxide trapped.

A very large, slow current called the thermohaline circulation carries warm water to Earth’s polar regions, where it cools and sinks to the deep oceans.

Maphoto/Riccardo Pravettoni via GRID-Arendal, CC BY-ND]

One such reservoir occurs in the western Pacific west of the Okinawa Trough in the East China Sea. The temperature of the bottom waters at this location is 37 to 39 degrees Fahrenheit (3 to 4 degrees Celsius), which means the hydrate cap is within about 4-5 degrees Celsius of its melting point.

Importantly, warm hydrothermal fluids are rising from below the carbon dioxide reservoir toward the surface. As the oceans continue to warm, the temperature difference between cold ocean waters and warmer hydrothermal fluids will decrease. This will cause the hydrate to thin, potentially to a point where it will no longer keep liquid carbon dioxide from escaping.

To date there has been no research to assess whether these ocean carbon dioxide reservoirs are vulnerable to rising ocean temperatures. But Earth’s pre-historic record clearly demonstrates that geologic reservoirs can be destabilized – and that when they are, it leads to rapid increases in atmospheric carbon dioxide and global warming. In my view, this represents an important unknown risk that cannot be ignored.

https://e360.yale.edu/features/will_climate_change_jam_the_global_ocean_conveyor_belt

...A similar string of moorings across the middle of the Atlantic, delving as deep as 3.7 miles from the Canary Islands to the Bahamas, has already detected a disturbing drop in this ocean’s massive circulation pattern. Since those moorings were installed in 2004, they have seen the Atlantic current wobble and weaken by as much as 30 percent, turning down the dial on a dramatic heat pump that transports warmth toward northern Europe. Turn that dial down too much and Europe will go into a deep chill.

Researchers have been worried about an Atlantic slowdown for years. The Atlantic serves as the engine for the planet’s conveyor belt of ocean currents: The massive amount of cooler water that sinks in the North Atlantic stirs up that entire ocean and drives currents in the Southern and Pacific oceans, too. “It is the key component” in global circulation, says Ellen Martin, a paleoclimate and ocean current researcher at the University of Florida. So when the Atlantic turns sluggish, it has worldwide impacts: The entire Northern Hemisphere cools, Indian and Asian monsoon areas dry up, North Atlantic storms get amplified, and less ocean mixing results in less plankton and other life in the sea.

A single Atlantic Ocean current system accounts for up to a quarter of the planet’s heat flux.

Paleoclimatologists have spotted times in the deep past when the current slowed quickly and dramatically, cooling Europe by 5 to 10 degrees C (10 to 20 degrees F) and causing far-reaching impacts on climate. Modelers have tried to predict how human-caused climate change might impact the Atlantic current, and how its slowdown might muck with the world’s weather even more. But years of intensive peering at this question haven’t yet provided much clarity.

Now, debate is raging about whether the recent Atlantic slowdown has been triggered by climate change, or is just part of a normal cycle of fast and slow currents. New studies in the last few years and months have come out supporting both prospects. The new data from the north, Lozier and others hope, might help to sort things out.

When the Hollywood blockbuster “The Day After Tomorrow” threw the Atlantic Ocean current into the popular spotlight in 2004, researchers laughed at its portrayal of an ocean current shutdown. In the movie, the world was plunged into a new ice age in a matter of days, with cold fronts literally chasing people at a sprint. But the disaster at the core of the film was based in some reality.

A huge amount of heat is moved around our planet by a single ocean current system — the Atlantic Meridional Overturning Circulation (AMOC) — which accounts for up to a quarter of the planet’s heat flux. The system is driven by density: waters that are cold or salty are denser and so dive down to the ocean floor. As a result, today, cold waters sink in the North Atlantic and flow southwards, while warm tropical waters at the surface flow northwards in the Gulf Stream, making northern Europe unusually mild for its latitude. But if northern waters get too warm, or too fresh from melting ice, then they can stop being dense enough to sink. That causes a major traffic jam for the water attempting to move north, and the system grinds to a halt.

Illustration depicting the circulation of the global ocean. Throughout the Atlantic Ocean, the circulation carries warm waters (red arrows) northward near the surface and cold deep waters (blue arrows) southward.

This has happened before. Researchers have spotted dramatic AMOC slowdowns of more than 50 percent during the last glaciation some 100,000 to 10,000 years ago, over a period perhaps as short as decades. The theory — which is being debated — is that as ice sheets got too big to stay stable, armadas of icebergs broke off, floated out to sea, and melted; even though the waters were chilly, the huge influx of freshwater made them less dense, and so they stopped up the currents. Looking further back in time to the last interglacial period about 120,000 years ago, which is more like today’s interglacial world, is trickier. But a study of some proxy measurements has shown that there may have been rapid slowdowns in the last interglacial, too.

“It seems to be a fairly stable system, until we push it just the right amount and then we’re in terrible shape,” says Martin. “I don’t think you want to play with the AMOC.”

The last review by the Intergovernmental Panel on Climate Change concluded that the AMOC is very likely to slow by the end of the century, perhaps by as much as 54 percent in the worst-case scenario, where emissions keep going up and global temperatures rise about 4 degrees C. But the range of possible slowdowns in these predictions is huge, starting at just 1 percent for an emissions-restricted world.

“The jury is still out. Weakening is a possibility, but it hasn’t been proven yet,” says one scientist.

If the North Atlantic current slows dramatically, then the entire Northern Hemisphere would cool; a complete collapse of the current could even reverse global warming for about 20 years. But the heat that ocean currents fail to transport northwards would make parts of the Southern Hemisphere even hotter. And a cooler north isn’t necessarily good news. Should the AMOC shut down, models show that changes in rainfall patterns would dry up Europe’s rivers, and North America’s entire Eastern Seaboard could see an additional 30 inches of sea level rise as the backed-up currents pile water up on East Coast shores.

But to pin down what the AMOC is going to do, researchers need to better understand what it’s doing right now. And that is proving tricky.

The problem researchers face is that the AMOC is extremely capricious, wobbling around more from year to year than the expected shift to date from global warming. Just like temperature or sea level records, this makes for a very noisy signal in which it’s hard to see long-term trends. “It’s analogous to the early difficulty seeing a global warming signature,” says Columbia University paleoclimatologist and oceanographer Jerry McManus. “Now that signature is compelling, but it took a while to see it clearly. Now that’s happening with AMOC. ”

The first string of moorings put in the ocean to investigate this current — the so-called RAPID array, with more than a dozen moorings from Florida to the Canary Islands — were deployed in 2004. They have shown a drop in water flow from 20 sverdrups (or million cubic meters of water per second) to 15 sverdrups over a decade. But the variability is huge. In 2009 to 2010, for example, the current was particularly sluggish for some reason, with water transport dropping by about a third. That helped to make the next winter the coldest for the United Kingdom since 1890, with heavy snowfalls and travel chaos. And from New York to Newfoundland, sea levels were boosted by five inches. Lozier’s data from the northern part of the ocean — in an array called OSNAP — will add a missing piece to the puzzle of what the current is up to.

...

Effects of Climate Change - Currents: NOAA's National Ocean Service ...

https://oceanservice.noaa.gov/education/tutorial_currents/05conveyor3.html

The global conveyor belt is a strong, but easily disrupted process. Research suggests that the conveyor belt may be affected by climate change. If global ...

Global Conveyer Belt: Ocean Current Slowing | Climate Central

https://www.climatecentral.org/gallery/.../global-conveyer-belt-ocean-current-slowing

Jun 6, 2018 - The global ocean conveyor belt is slowing down, impacting climate, sea ... But a larger ocean circulation caused by differences in temperature ...

Global Ocean Conveyor Belt | Climate Matters

medialibrary.climatecentral.org/resources/global-ocean-conveyer-belt

Jun 6, 2018 - The global ocean conveyor belt is slowing down, impacting climate, sea ... But a larger ocean circulation caused by differences in temperature ...

How Climate Change Could Jam The World's Ocean Circulation - Yale ...

https://e360.yale.edu/.../will_climate_change_jam_the_global_ocean_conveyor_belt

Sep 6, 2016 - The Atlantic serves as the engine for the planet's conveyor belt of ocean currents: The ... “It is the key component” in global circulation, says Ellen Martin, ... how human-caused climate change might impact the Atlantic current, ...

Scientists Say Ocean Circulation Is Slowing. Here's Why You Should ...

https://insideclimatenews.org/.../atlantic-ocean-circulation-slowing-climate-change-hea...

May 7, 2018 - Sign up to receive our latest reporting on climate change, energy and ... In the Atlantic, the ocean conveyor belt is known as the Atlantic Meridional ... Maine has warmed faster than 99 percent of the global ocean over the past ...

2016?

The California Current flows southward along the West Coast of North America delivering cool, nutrient-rich water from British Columbia to Baja California. Prevailing northwesterly winds drive the current and stimulate

upwelling, a process by which cold water rises from the depths to support biodiversity off the coast.

Weird is the new normal

Life in the California Current naturally fluctuates from year to year, partially due to temperature changes, said John C. Field, a fisheries biologist with the National Oceanic and Atmospheric Administration (NOAA).

Purple-striped jellies and other gelatinous creatures sometimes dominate the California Current. The reasons are still a mystery.

In cold-water years, he says, upwelling brings nutrient-rich deep waters to the surface, typically supporting an abundance of rockfish, krill and market squid. Warm-water years, when less upwelling occurs, bring more sub-tropical species, such as pelagic red crab. Some years, jellies and other gelatinous creatures dominate the current, for reasons scientists don’t yet understand.

John participates in an ecosystem survey that monitors annual changes in marine life off the coast of California. Throughout the survey’s 33 years, he said, only one regime has dominated at a time: either a cold-water or a warm-water regime. The spring of 2015, however, was different. There were high catches of cold-water species, warm-water species, and all the gelatinous stuff.

“It was really a blend of everything,” John said. “We usually get one type of thing or the other, but nothing like this. It was a really unusual year.”

Scientists don’t know what causes weird years like this — or whether the changing climate will make them more frequent.

Fishery business

As sea surface temperatures rise, fish are getting fidgety. Scientists predict cool-water fish populations will shift farther toward the poles in the Northeast Pacific Ocean. The fish in the California Current may follow suit, said Tony Koslow, a researcher from Scripps Institution of Oceanography at the University of California, San Diego.

In a paper published last year, Tony and others found the abundance of fish in the California Current has declined dramatically for the past four decades, a trend likely driven by climate change....

https://oceanexplorer.noaa.gov/explorations/02quest/background/upwelling/upwelling.html

6/17

https://sanctuaries.noaa.gov/news/features/0609_changingclimate.html

...Changes in Currents and Upwelling

Scientists have found that ocean temperature has a major influence on currents and upwelling activity, which are fundamentally important to marine ecosystems around the world. Upwelling - circulation of cool water from the deep ocean to warmer areas near the surface - is especially crucial in places such as Cordell Bank National Marine Sanctuary off the Northern California coast and Stellwagen Bank National Marine Sanctuary off Massachusetts, where thriving communities of marine life depend on the nutrients it pulls up from the depths.

It is difficult to predict how warming sea surface temperatures will alter upwelling and currents, but any changes in ocean circulation are likely to have serious consequences for marine life. Without the influx of nutrients from deep water, sites like Cordell Bank and Stellwagen Bank could see devastating collapses in marine communities, with declines in tiny organisms like plankton and krill at the bottom of the food web leading to starvation for fish, seabirds, whales and other high-level consumers.

ocean warming, demoic acid, loss of food

drilled early ff sci report said warming wd shift fish pops.

omg (whales starve off CA no food)

Pompeo actually just cheered the ‘new opportunities’ presented by the Arctic’s melting ice sheets

by Cody Fenwick May 6, 2019

Secretary of State Mike Pompeo has never been terribly worried about climate change, but in a new speech to the Arctic Council Ministerial Meeting in Finland on Monday, he seemed…

---

https://www.alternet.org/environment/climate-disaster-looms

// irish famine year w/o summer

...because the UK, Germany, the Netherlands, Poland, and all of Northern Europe and Scandinavia are at roughly the same latitudes as the area from central Canada to Alaska, the only thing that keeps them warm enough to sustain rich crop yields (unlike Alaska) is the heat distributed to them from the Great Conveyor Belt/AMOC.

And the main thing that keeps the AMOC moving is the incredible salinity that forms in the North Atlantic as the current gives up both heat and water vapor, (leaving behind the salt) into the soon-to-warm-Europe air with the warmth. Because the strongly saline water is so much denser/heavier than normal seawater, it sinks vigorously toward the deeper parts of the ocean, pulling the rest of the current behind it and helping maintain the AMOC’s flow.

Should something begin to inject fresh water into that region, thus diluting the salinity of the AMOC there, it would reduce the density of that water column and thus could shut down the Conveyor Belt. And that would shut off Europe’s main heat source.

This is a scenario that most climate scientists—until this year—considered a remote possibility, even in the next century.

But it’s beginning to happen right now, both in Antarctica and off the coast of Greenland and Western Europe, because of massive glacier melts.

One part of the thermohaline circulation of the AMOC runs around Antarctica. And, because of global warming, Antarctica is shedding hundreds of billions of tons of ice-melt fresh water into the ocean every year—which is diluting and cooling saltwater and reducing local thermohaline circulation.

As Chris Mooney notes in the 4/3/18 Washington Post (“One Of The Most Worrisome Predictions About Climate Change May Be Coming True”):

“The new research, based on ocean measurements off the coast of East Antarctica, shows that melting Antarctic glaciers are indeed freshening the ocean around them. And this, in turn, is blocking a process in which cold and salty ocean water sinks below the sea surface in winter, forming ‘the densest water on the Earth’...”

Meanwhile, the northern part of the Great Conveyor Belt—which warms Europe—is also faltering in the North Atlantic, largely as a result of hundreds of billions of tons of cold, fresh water from Greenland glacier-melt, caused by global warming, pouring into it every few minutes.

New research from University College London and the Woods Hole Oceanographic Institution (“Anomalously Weak Labrador Sea Convection and Atlantic Overturning”) found that the hiccups in the Great Conveyor Belt began around the time of the Industrial Revolution, when we—for the first time in millions of years of human evolution—started spewing billions of tons of fossil-fuel-derived carbon dioxide into the atmosphere. The Great Conveyor Belt has been deteriorating ever since, and the speed of its disintegration is now alarming observers worldwide.

Scientists are concerned that we may even be close to a tipping point, where this river of warm, salty water could change or collapse rapidly and with little warning—a change that probably would take tens of thousands of years to undo or reset.

As Dr. Michael Mann, one of the world’s most respected climate scientists and the founder of the “hockey stick” that Al Gore popularized, told me on my radio/TV program April 24th:

“This is a potential tipping point in the climate system, which is to say it could happen very abruptly once it starts to happen. The danger is that we’ve already seen a substantial slowdown in this ocean circulation pattern, [and that] suggests the possibility that we could be right up against that tipping point where it essentially just shuts down.”

Mann added that until the recent research came in, pretty much everybody thought we had 100 years or so before we needed to begin to even seriously consider this potentially catastrophic scenario:

“If you talked with climate modelers even 5 or 6 years ago, they would have told you that this scenario isn’t likely to play out for at least another century or so. … So something that we didn’t expect to happen for the better part of a century is happening already.”

And lest Americans think this will only be a European problem, shutting down the AMOC/Gulf Stream, which warms the American northeast, would also have a catastrophic impact on that region of the United States and Canada.

As NASA’s scientists note on one of the few climate-change web pages the Trumpies haven’t yet removed:

“Without the vast heat that these ocean currents deliver—comparable to the power generation of a million nuclear power plants—Europe's average temperature would likely drop 5 to 10°C (9 to 18°F), and parts of eastern North America would be chilled somewhat less. Such a dip in temperature would be similar to global average temperatures toward the end of the last ice age roughly 20,000 years ago.”

Compare that to the damage a mere 1° C drop in the 1816 Year Without a Summer caused to both Europe and the eastern part of North America in 1816. Civilization—and billions of people—probably would simply no longer survive as we know it....

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