Will AMOC Run Amuck?
The North Atlantic cold blob suggests our most critical planetary climate system is in peril
In late September 2024, researchers at the University of Barcelona estimated on average for the last decade Greenland has been losing around 300 billion gigatons (Gt) of ice a year. In 2012, that figure was about 610 billion Gt and in 2019 560 billion Gt. A gigaton is equal to one billion tons. Multiple studies of the Greenland ice sheet confirming the loss have been performed in recent years. This astonishing melt is diluting the seawater salt critical for the Atlantic Meridional Circulation (AMOC) to function, with dire implications for the Earth’s climate and human survival. More perspective? 30 million tons of Greenland ice melt every hour. In January 2024, researchers at NASA’s Jet Propulsion Laboratory reported Greenland has shed about one-fifth more ice mass in the past four decades than previously estimated based on this study published in Nature.
It feels ironic that the Atlantic Meridional Overturning Circulation (AMOC) was discovered by a slave trader, Captain Henry Ellis, who in his profession practiced some of the earliest vile exploitation of the Global South for colonial power. After all, material greed is what’s driving AMOC to collapse, and there are few crimes more heinous than enslaving other human beings for profit. In 1751, Ellis lowered a bucket into the depths of the Northern Atlantic Ocean, a primitive temperature “sea-gauge” discovering that the deep water was icy cold, yet at a mile down it came up no colder. Unwittingly, Ellis had discovered AMOC, and humanity had just taken its first temperature reading of the deep ocean. He had no clue that he had discovered the most critical convection system on the planet. To Ellis and his crew the deep water merely provided cold baths in sultry temperatures and chilled wine and water.
He wrote to the British clergyman Reverend Stephen Hales, the devisor of the gauge as well as an accomplished scientist:
“The cold increased regularly, in proportion to the depths, till it descended to 3900 feet: from whence the mercury in the thermometer came up at 53 degrees (Fahrenheit); and tho’ I afterwards sunk it to the depth of 5346 feet, that is a mile and 66 feet, it came up no lower.”
How the AMOC works
The massive AMOC current stretches across the equator, reaching from Greenland to Antarctica, and brings cold water south and warm water north. AMOC is part of the global ocean circulation “conveyor belt” that regulates land surface temperatures and circulates nutrients ocean life depends on. It’s critical for temperate weather on the European continent, rain belts southern African agriculture depends on, the timing of India’s monsoons, and the avoidance of accelerated melting of Antarctic ice sheets. The AMOC also prevents the catastrophic rise of seawater on the US east coast.
The AMOC circulation system
The AMOC is part of a process called thermohaline circulation. Deep-ocean currents thousands of meters below the surface are driven by differences in the water’s density, which is controlled by temperature (thermo) and salinity (haline).
In polar regions, ocean water forms sea ice. When sea ice forms, the salt in the seawater is left behind, increasing its density, causing it to sink. Surface water flows in to replace the sinking water, eventually becoming cold and salty enough to sink as well. This initiates the deep-ocean currents that drive the global conveyor belt. Eventually, the water gets pulled back up towards the surface and warms up in a process called upwelling, completing the cycle.
The AMOC is part of a worldwide system of ocean currents responsible for the climate that has allowed human life (and our mammal cousins) to thrive.
Ice core samples from Greenland and Antarctica show evidence of the AMOC’s collapse in the past. Radioactive decay found in the samples of Protactinium-231 and Thorium-230 provide evidence of multiple ice age events with the crippling of the AMOC. Scientific consensus finds the continued profligate burning of fossil fuels to spell its possible collapse again by 2100, here, here and here. Doubtlessly, I could find more links to this particular consensus. However, there is also debate within the science community concerned its collapse could occur far earlier. Regardless of timing, collapse of the AMOC would wreak havoc on the world and result in the deaths of billions.
The Cold Blob
Predicting collapse of the AMOC is dependent on future levels of GHG emissions. This article from Phys.org indicates that in high-emission climate model scenarios the AMOC collapse tipping point could have begun as early as 2023 or will come as late as 2076, with a median tipping point of 2055. Under intermediate scenarios, the tipping point has been placed between 2026 and 2095, with a median of 2063. This article speculates on 2055, but links to a U.N. climate report favoring 2063. Clearly, consensus in the science community has not been arrived at. In this writer’s opinion an “exact” tipping date will never be known. Monday at 1pm? Tuesday at 3? What is known is that the AMOC is slowing rapidly, with the stakes being extinction. It makes sense to this writer to take action based on the most pessimistic of opinions, don’t you agree?
Shared socioeconomic pathways
Shared Socioeconomic Pathways (SSPs) are dependent on how much more greenhouse gases we insist on emitting. These pathways ranging from attempting sustainability to ignoring our plight entirely range from SSP-1 to SSP-8.5. SSP-1 requiring very low GHG emissions and cuts of CO2 for net-zero around 2050 is dead from world leaders ignoring the 2015 Paris Climate Accords and earlier 1997 Kyoto Protocol. SSP-8.5 — very high GHG emissions and CO2 emissions — tripling by 2075 is still very much on the table with Trump and fellow ignoramuses stomping on the oil exploration gas pedal and undermining environmental laws and agencies already proven inadequate. How do you think we got here? SSP2-4.5 appeared most likely until Trump II, 2.0° C warming by 2021. Now the majority of climate scientists are seeing 2.5° or higher by 2100 as we struggle at 1.5° C.
The relationship of emissions, global warming, the AMOC, social justice, and even survivability are inarguable.
As record wildfires and floods reach new levels every year and wet-bulb temperatures take lives, the cold blob at the southern tip of the Greenland ice sheet may appear as an outlier as the globe grows hotter, but it’s not. This cool spot in the North Atlantic is a product of fossil fuel generated heat, as incomprehensible amounts of ice melt away forever in practical human terms. The Greenland ice sheet will melt entirely. It’s been destined to do so since 1959, probably before that, the first year atmospheric carbon dioxide levels were kept. In 1959, CO2 stood at 316 ppm. Ice core evidence proves the Greenland ice formed around 300 ppm of CO2 or less. I wrote about that in The Greenland Ice Sheet is Gone in 2024. Today, CO2 stands at 427 ppm.
Who are the monsters?
In The Blob, an alien monster crashes from outer space. Like billionaires, it envelops living beings and becomes more aggressive, eventually growing larger than a building. Perhaps AI data centers being built by the hundreds, covering vast acreage and stealing one of our most basic human rights — access to water in an increasingly drought stricken world — would be the apt comparison now. These mutants of our own creation promulgated by our elected and appointed “leadership” who some stupidly admire are now absorbing us in their malevolent, inhuman psychopathy. Those who have never known limits can’t see them, and their idea of worth is in their ability to crush you, not in the reward of lifting others. They are without souls.
As entertaining as monster movies can be from Mary Shelley’s classic Frankenstein to hokey 1950s sci-fi, these stories are about us. We are the monsters. Were I an alien being on another planet, I would tremble at the arrival of humans. Every dead Gaza child is proof of our barbarity.
You my friend, willing to read these bitter words are hope. Only by embracing reality do we have a chance for a future. Since voting got us here, demonstrating that both our parties destructive to our minds, bodies and futures, taking down the system is our only and last chance. Money is the lifeblood of the monsters. Boycott, strike, stop paying taxes that finance death. We have the numbers, but we must act together and with great courage.
What will you tell your children and grandchildren if you sit this one out?
No problem, AMOC usually starts up again after about 1000 years. The ocean's recovery after its death from our CO2 emissions could take a relatively minor 5 million years. Without cheap energy these societies collapse anyway. Pick your poison. And we can't sit here writing policy that applies to all the world, they are all on their own track.
This is the article that did it for me. We have interrupted the carbon cycle and it will take eons to repair itself.
https://www.theguardian.com/environment/2025/aug/19/a-climate-of-unparalleled-malevolence-are-we-on-our-way-to-the-sixth-major-mass-extinction?CMP=share_btn_url