Slowing Atlantic current could trigger sudden climate shift

A slowdown or collapse of currents in the North Atlantic would have dire implications for large parts of the world

by Eddie Ford

For a while now, there have been alarming media reports about the possible breakdown of the Atlantic Meridional Overturning Circulation (AMOC) — a vast system of ocean currents that is a key component in global climate regulation, of which the Gulf Stream is a part.

Most people brought up in Britain know all about the Gulf Stream, as they were probably taught it at school like this writer. This is what keeps Britain with a mild climate: stopping us from freezing in winter and making things somewhat cooler during the summer. Essentially, AMOC is a vast marine conveyer belt, where one current gets buried under the other, as it carries heat, carbon and nutrients from the tropics towards the Arctic Circle, where they cool and sink into the deep ocean. This constant churning helps to distribute energy around the planet and modulates the impact of human-caused global warming.

But what has been going on for about the last 100 years, certainly from the 1950s, is Arctic melting, which is releasing non-salt and colder water into the Atlantic and changing the density of surface waters. For example, analysis of satellite records has shown that over the past three decades an estimated 11,000 square miles of Greenland’s ice sheet and glaciers have melted — an area equivalent to the size of Albania and amounting to 1.6% of its total ice cover. As ice has retreated, the amount of land with vegetation growing on it has increased by 33,774 square miles — amounting to a near quadrupling of wetlands across Greenland, which, of course, are a source of methane emissions. As a consequence of such climate behavior, AMOC has declined 15% over this time period and is in its weakest state in more than a millennium — which could prove particularly disastrous for marine life and the communities that depend on it.

Hence we have had a new report from the University of Utrecht published in the Science Advances journal that says we stand on the cusp of a dangerous slowing down of AMOC — not a “collapse” as talked about in some media reports, which is sloppy talk. But it is what you will read in a lot of headlines, especially in sensationalist tabloids like the Daily Mail, often accompanied by images from the 2004 Hollywood blockbuster, The day after tomorrow, that depicts a catastrophic new ice age following the disruption of AMOC, with New York freezing over in a mere weekend or so.

Tipping point

No, that is not what will happen. But what the Utrecht study says is that there is a distinct possibility of slowdown sometime between 2025 to 2095. That is, this century and would represent a climate tipping point.

Of course, any Marxist worth their salt knows all about tipping points — the change from quantity to quality. That is something now accepted in all sorts of different fields, but it used to be a big controversy in biology, and also — for that matter — in climate science until relatively recently. In this context, it is worth reading the last chapter of Charles Darwin’s On the Origin of Species, where he warns his readers against this ‘leap’ question, because this is Marxism — even if he does not explicitly say that. But he thinks that with a leap comes social revolution and Darwin, being a committed liberal reformist, did not want a repeat of Chartism. This attitude is adopted by bourgeois science, to use shorthand, when it comes to the climate question.

However, anti-leap prejudice has been overthrown and increasingly scientists have come around to the view that the climate does develop qualitatively — it does go through leaps, shifting from one pattern to another. It can shift from AMOC, almost overnight into another system. No-one knows exactly what the system will be like, but they are saying that Britain, for example, would get a lot colder and wetter. Naturally, some climate sceptics think they are on to something by pointing out that Britain getting colder in the midst of global warming is a paradox. Yes, they are right, but it is not as simple as saying global warming means the temperature will increase everywhere. Rather, we are talking about complex and chaotic climate patterns, and therefore a change in weather patterns.

Breaking new ground, the Utrecht papers makes various predictions by looking for warning signs in the salinity levels in the southern Atlantic Ocean between Cape Town and Buenos Aires — using a computer simulation of changes over a period of 2,000 years. Of course, some scientists dispute the findings and the various theoretical models, which is the very nature of science — the open contestation of different and contrasting views. The UK Met Office, for instance, believes that large, rapid changes in AMOC are “very unlikely” in the 21st century.

Sea levels

Anyway, the study mapped out some of the consequences of an AMOC slowdown. Sea levels would rise by a meter, inundating many coastal cities like New Orleans, Amsterdam, Bangkok, large parts of London, etc., on a permanent basis. Therefore these cities have to be defended by ever higher barriers or abandoned — like Jakarta (Indonesia is building a new capital city more than 1,000 kilometers away). The wet and dry seasons in the Amazon would flip, potentially pushing the already weakened rainforest past its own tipping point — the jungles turning to something more like the Serengeti in Africa. Temperatures around the world would fluctuate far more erratically. The southern hemisphere would become warmer, whilst Europe would cool dramatically, with a country like Britain becoming a rather unpleasant place to live.

Yes, true, AMOC has collapsed and restarted repeatedly in the cycle of ice ages that occurred from 115,000 to 12,000 years ago. But, according to the Utrecht paper in Science Advances, AMOC is on track towards another major shift — this time largely human created. The precise point is that this shift would not occur over a protracted period between 2025 and 2095, perhaps giving us time to adapt, but would happen quickly at some point in this time band — an abrupt qualitative shift with dire implications for large parts of the world. And, when it happens, the changes will be irreversible on any reasonable human timescale.

In other words, the Utrecht scientists and others are saying we do not know when this will happen, but, if something urgent is not done right now about reversing CO2 and other emissions, this is the sort of thing that can happen — the total degradation, if not destruction, of existing agricultural and habitat patterns. All this at a time when the European Union’s Copernicus climate change service, along with others, showed that for the first time global warming has exceeded 1.5°C for an entire year. Of course, the Paris agreement was not about one year over 1.5°C, but an established pattern over many years. But we have breached that ‘target’ now and if we carry on in that direction, this is what will happen — runaway global warming, more extreme weather, a weakened AMOC, untold millions on the move, and so on.

The world’s sea surface is also at its highest ever recorded average temperature, another ominous sign of climate crisis — especially worrying, given that ocean temperatures do not normally peak for another month or so.

Ruling class

Clearly, the solution has to lie outside capitalism. But, having said that, we have to point out that the ruling class, or at least sections of it, know this — something has to be done; business as usual is not an option. It is hard to believe that they are all stupid or criminally self-interested.

Yet that does not mean proletarian socialism, of course, which is the most democratic and logical thing to do — you actually have to overcome the profit drive, production for the sake of production. But tragically the working class at present is hardly organized on an international basis: it has not readied itself to become the ruling class.

Therefore expect sections of the ruling class to act — maybe the army or the secret state — to impose radical and draconian measures to avert the crisis. Far from it being a humane outcome, expect the opposite, some sort of horrendous outcome, a form of climate socialism — communists use the term in the same way that the German high command in World War I talked about war socialism (Kriegssozialismus).

That was not heaven — it was hell for the working class. This is a danger that we should be acutely aware of. The big problem with protest politics by groups like Just Stop Oil and Insulate Britain is that they could be easily recruited to such a project — such a regime would be attractive to celebrities, the rich and powerful, demagogues, chancers, etc. Sections of the capitalist class would resist, naturally, but others would welcome it on the grounds that it is either climate socialism or social breakdown.

Admittedly, talking about the possible far-sighted nature of some sections of the ruling class might sound a bit fanciful, when you have the drive by Rishi Sunak to ‘max out’ the extraction of North Sea oil and gas. Then we have the Labour Party abandoning its pathetic £28 billion-a-year green package of investment. Pathetic — because it goes along with the idea that you can be both ‘green’ and pro-business, since there is lots of money to be made with electric cars, solar panels, battery technology and suchlike. True, but this is a perverse argument, as capitalism is inherently anti-ecological. Indeed, you could not devise a more anti-ecological system, even if you wanted to. As for things like electric cars, the idea that they are ‘green’ is absurd — how do you think they are made?

So, while Labour says it is still committed to the same green aims and aspirations, do not believe a word of it — such aims and aspirations would mean breaking with capitalism. Indeed, everything at the moment is pointing to the likelihood that we will burst through 1.5°C and beyond on a permanent basis. Where we end up is impossible to predict, but the crucial point is that the global climate is like the proverbial oil tanker — it takes a long time to turn around.

The ice in the Arctic and Antarctica will continue to melt for at least the next 100 years, even if we were to magically have immediate zero net CO2 emissions on the planet — adding to the momentum of increasing temperatures in an appalling negative feedback loop.

Reposted, with permission, from the UK newspaper Weekly Worker, February 15, 2024. Climate & Capitalism welcomes further debate and discussion on this subject.