Long Read

The Situation

A  recent, very controversial, simulation suggests that the Atlantic meridional overturning circulation (AMOC) may reach a tipping point much sooner than originally thought, beginning as early as 2025,  and could cause major changes in water levels and climate too fast for ready adaptation in some areas1.  As excerpt:

Climate scientist Tim Lenton, director of the Global Systems Institute at the University of Exeter, has also used computer models to assess how an AMOC shutdown could affect the world’s food supply. The dramatic cooling in the Northern Hemisphere would cause a shift in the band of clouds and rainfall that encircle the globe at the tropics. The monsoons that typically deliver rain to West Africa and South Asia would become unreliable, and huge swaths of Europe and Russia would plunge into drought. As much as half of the world’s viable area for growing corn and wheat could dry out.

“In simple terms [it] would be a combined food and water security crisis on a global scale,” Lenton said.

Since the AMOC transports heat northwards in the Atlantic, a collapse would tend to cause a significant cooling in the North Atlantic Ocean, which would drive cooler temperatures over much of the Northern Hemisphere, especially Europe and North America, and potentially across the whole hemisphere …. This, however, would compete with the effects of global warming, with the net effect depending on the magnitude of the latter. The reduced heat transport would slightly add to warming in the Southern Hemisphere. Cooler ocean temperatures in the North Atlantic would drive reduced evaporation and hence less atmospheric water vapour for precipitation ….. They would also result in an increase in Arctic sea ice. As much as half of the world’s viable area for growing corn and wheat could dry out. GTP-full-report-071223 (2).pdf

This is a frightening possibility, although not as frightening as the movie The Day After Tomorrow. More information and links can be found below in a very helpful overview from a government staff person.The direct effects of greater cooling on North America are but vaguely known.  Even so, we can be sure that the effects elsewhere will impact us here however indirectly.  While the impact on Canada and North America may be uncertain, it would be better to think ahead than to wait passively.

Thinking Ahead to an Ethical Practice

People should do some deliberate thinking about an ethic to hold onto as we live into that future.  Attitude and action will be important.  Attitude:  something better than fear, thoughts of self defense, panic, or running away.  Something explicit we can put out in front of ourselves like the arrowhead-shaped blade of a snow plow to break through fear, and which will inspire others to move in the same forward direction.  It is often said that when troubles come our way, it’s not just the troubles themselves that determine our future, but our response to them.  I maintain that what we are doing at the moment to move things along in our lives, is more important than just responding to troubles.

There are many matters to consider when planning for such an uncertain future.

1.  Attitude and the Lessons of COVID   

This is where the ethic is important.  Ethics is the practice of putting forth your values explicitly to guide you consistently, so that everyone around you knows what to expect of you – neighbours, employers, employees, co-workers, family, friends, political affiliates. Your values will predict how you will treat not only people but the rest of life around you near and far, i.e., the environment.

I suggest two primary values:  generosity and compassion.  Generosity means being willing to do all you can in the event for the benefit of others, as well as for yourself.  It means doing not just the minimum, staying on your side of the street, in your own box. It means not giving in to distrust of others as a first response.  There is a religious expression which can help with this:  be as concerned for others (including the environment) as for yourself, neither more nor less.  This is does not requires self-sacrifice, but it does mean walking arm–in-arm with others, all of you holding on as you move ahead without breaking away.  I want to emphasize the metaphor of the snow plow (with snow as the analog of fear), as all these problems head for us.  Generosity is a forward-leaning attitude and action.  Think of a snow plow with an arrowhead-shaped blade thrusting forward and pushing aside the snow.  This is far healthier than one with the V-shape which can only capture the snow and hope to move forward against ever heavier loads.  Generosity breaks through the fear that awaits us.  Fear brings defensiveness and immobility.  Generosity brings agency; fear brings paralysis until anger, the flip side of fear, moves us to act without thought or morality.

Compassion is walking with others through life, being next to them in a way that each  supports the other, leading forward but accepting that not everyone can move so quickly or sure-footedly.  Think of it as pushing someone in a wheelchair while someone else pushes on your back, or carries some of your gear for you, or relieves you for a while.  It can mean listening to someone else’s story and telling them yours – so that no one’s life story goes untold and unheard.

We have learned some things from the COVID years which may make us pessimistic about adapting to threatening circumstances.  Not everyone takes well to being required by law to act in a certain way; we have seen medical professionals treated terribly as they try to save people from COVID; we’ve seen outright denial that COVID is a real problem, and we’ve seen people deliberately and willfully lie about its significance. We’ve also seen great apathy lately:  in my area COVID is returning quickly because so few people have been keeping up with the vaccine.  Some pharmaceutical companies already suggest that the market for vaccines is too unprofitable for them to attune the next vaccine to the next variant.  So even those who may desire the next shot, may find there is nothing new to get.

Peoples’ attitudes and value systems will guide how we handle crises more than will government action.  We should encourage people to look at situations through our value systems, without judging them for theirs (assuming that our own well-being is not unavoidably damaged by their values).

  1. Proximity

Some people’s first reaction to AMOC may be panic:  get away from others in order to protect themselves.  Isolating or being in areas of small populations where everyone knows one another may be appealing, but if the new conditions make it difficult to access medical attention, or limit transportation of food or transmission of electricity or transportation of different fuels, being remote may be quite disadvantageous.

My own choice will be to remain in urban areas where, I hope, proximity to many people and services will make living easier.

We know from COVID lessons that many people who live in crowded quarters may suffer more from inadequate air circulation, heat, and air conditioning, and may find public transit not meeting their needs safely.  These are problems for which provision should be made beginning NOW, not waiting for AMOC or any other next crisis.

3.  Supply Chain

It may be difficult to grow things we need in some places (think of the drought already in Alberta), inadequate fuel to transport goods, and fewer able and willing people to grow food, make things, and conduct scientific activities to produce things we need now, let alone in the future.  Again, I suggest that being in communities where many people of many abilities live and work, will ameliorate these difficulties.  Highly infectious disease simultaneous with AMOC problems may make closeness a problem, but closeness may also make it likelier that solutions can be found.

  1. Energy

The immediate future of energy availability is murky.  There are questions of sources and transmission. In Canada we have nuclear, gas, water, wood, wind, solar, and hydrogen.  Even when sources are nearby, power must be distributed to other locations — their nearness does not itself guarantee reliability, because it still comes through transmission lines. Those areas where lines are underground (some but not all cities) have greater reliability.  Those with above ground lines are more at risk during bad weather or winds, or sometimes, animal activity.  But the shorter the transmission distance, the less opportunity for long-lasting interruption.  This doesn’t necessarily argue for greater reliability in cities than in rural areas, but it may, depending on how the distribution network is placed.

Other considerations, though.  Hot weather may evaporate lakes, reservoirs, and rivers, which could diminish power generation at water sources, and could also diminish cooling capabilities at nuclear power stations.  On the other hand, severe cold can freeze water and perhaps cause difficulties.  Frozen Great Lakes diminish sea transport of goods.  Foul weather can slow transport of fuel and other supplies by truck or rail.  Fuels are rarely extracted within cities. They require transport from other areas.  One assumes that cities will be supplied more readily than remote areas because more people are served in cities.

Cloud coverage can diminish solar energy production, some winds can be too strong for windmills to operate, and there can be days without winds.  Gas, oil and gasoline supplies and transport may be less susceptible to weather, except that they require energy to be extracted and refined, and at the end of the pipeline, must still be transported by truck.  As I say, with  changes in the environment caused by AMOC, the levels of risk are difficult to know.

  1. Food

This may be subject to the drastic climate change.  Food grown in Canada may be more emphasized; and imported food less so, because of supply chain interruptions and higher costs, and, of course, perhaps less availability because of changing growing conditions elsewhere.  Our attitude toward some crops, dairy products and meats may be changed because of paucity of farmed products, or unsuitable weather conditions for outdoor animals, or problems growing appropriate feed for the animals.  Because growing areas are often distant from cities, particular attention to the growers’ needs will be emphasized, including communication, transport, communication, and support services such as education and medical care.  Distance from cities may therefore not be as isolating as might otherwise be supposed. But planning for these possibilities is necessary.

Pharmaceuticals represent the same problems as food, because so many medications come from and/or through India and China.  Weather conditions interrupt transport and communications. Lack of supporting for local workers, research, basic ingredient availability and quality, and geopolitics, may interrupt the availability of medicines. Canada and the U.S. may have to emphasize more domestic origin and production of pharmaceuticals.

There are also the problems of distribution.  Not all pharmacists, not even those in large chains, always have every medication on hand. Some medications can be dispensed only under supervised consumption, while others must be ordered several weeks in advance and kept in particular environments.  Again, proximity to distribution locations will be important, and may well mean that living in cities is necessary.

  1. Water

The droughts in West Africa and South Asia, together with the cooling in Europe and North America will affect food production as well as animal, human, and plant health, with perhaps unpredictable results during an unspecified length of time. Of course whether the world can reduce its heat production will have something to do with that. In Canada we will have to watch the effects on the St. Lawrence Seaway, and we and the U.S.  will have to be careful of the Great Lakes, with attention to which country uses how much water and for what purposes.  We see that Alberta, and several U.S. states, already are having to adopt revised water usage standards even now, for agriculture, mining, residences, and manufacturing.

Ontario depends somewhat on local water power, and on water power from Quebec (which benefits from Newfoundland and Labrador’s water generating capacities) for electricity.  Rivers depend upon melting snow, of which there seems to be less recently.  Perhaps if we, like Europe, are colder, that will help.  Nuclear energy needs coolant, so the water levels near generating stations needs to remain cool and deep enough for their purposes.

Adequate water for agriculture and pasturing, healthy crop and trees and shrubs and wetlands, cooking, cleaning, hygiene, food, and some industrial processes, must be made available in many places of scarcity (perhaps another reason to live in close proximity to reduce the distances for conveying water), in the face of uncertain snowfall, drought, pollution, and damaging weather. 

  1. Income

With so many things about the future of our economy unknown, it is likely that many people will have a tough time making a living, In our current economic system, those who succeed may exacerbate the income inequality we already have.  We will need a way for people to afford to live – a basic income with claw backs only at very high levels of earned income.  This will be necessary for people to purchase their needs, and for money to circulate among businesses. A basic income could also minimize natural anxiety about where the next meal will come from and whether today’s shelter will be there tomorrow. This will be necessary for social and political stability and should be administered much as the Canada Pension Plan is, pretty independently from politicians.

  1. Government

We will need better government than we have now.  Administrators must organize well, plan into the future, and design basic income, taxation, and monetary distribution even during extreme strains on communication, data processing, and information storage.  We need policies developed on the basis of good evidence and thought, and not so subject to ideological swings in governments.  We need elected politicians who, like Canadian appointed senators, must have backgrounds of personal and employment accomplishments, and a history of contribution to the general good.  Ideologies must give way to good governance. Politics along with economics, must be employed for the good of all. Politics must not continue to be a privileged sandbox where politicians and staffers play their own games and produce poor theatre as a substitute for thoughtful debate, planning, legislating and governing.

  1. Homelessness

We haven’t been doing well with this since the Canadian government abandoned its role in providing affordable housing in the 1990’s (Multiple Barriers:  the Multilevel Governance of Homelessness in Canada, Alison Smith).  Continued lack of planning, arguments among the different levels of government, and the massive increase in allowed immigration, refugee entrants, and asylum seekers, together with labour shortage in some industries and all the difficulties of COVID and supply chain problems, have left us with devastating and immoral consequences.  New, highly dangerous and addictive illicit drugs, along with increases in the number of people with mental health problems, have contributed. 

AMOC, following the earlier climate changes which have already been raising water levels along eastern coastlines, will increase the east water levels, and may force people to relocate their homes, businesses, and communities, as has happened in Louisiana, for example (Louisiana town moves to higher ground amid growing climate crisis (cnbc.com)).  Assuming all inland property is currently owned by somebody, it will be necessary to compensate people for the loss of their business and residential locations, the cost of moving, and the cost of buying or renting space elsewhere.  This requires more government action to keep capitalism from making even more people poor, and from depriving people who must relinquish/sell their land to newcomers, from feeling unfairly deprived of their property.

A great deal of planning, discussion with affected people, and collaboration will be needed NOW, as we begin a different future much earlier than expected.

10. Climate Refugees

With the frequent mass starvation due to heavy storms and also to rising temperatures and drought in many regions, one might expect that more people will want to move to areas like ours.  But Hein de Hass (How Migration Really Works:  the Facts about the Most Divisive Issues in Politics), citing his own thirty years of study and many multi-national and U.N. research projects and reports, maintains that this is unlikely to happen.  Rather, there will be need to improve those areas’ farming, irrigation, and water conservation methods, and to help people there create governments that are more set on providing for them than on warfare and self-aggrandizement.

Based on all the research in that book, I suggest we are most likely to adapt to fewer imports from those areas and to providing them more aid to live where they are. Given our own uncertainties, we may have difficulty with these problems.  But if we adopt an ethic of generosity and compassion, we will work very hard to help.

11.. Geopolitics and Local Politics

I would be remiss not to list this as a consideration.  2025 will be a federal election year in the U.S. and possibly in Canada.  How either of these two countries deals with the climate crisis generally, and the tipping point of AMOC specifically, will be a concern.  Will they acknowledge the beginning of the tipping point if it occurs in 2025?  Will each have a political environment (see above under Government) that will exercise generosity and compassion? Will they show transparency and dedication to the good of their citizens and residents?  It was only at the end of last year that the Ontario government, under pressure from the loyal opposition party and the advocacy group Seniors for Climate Action Now! (Seniors for Climate Action Now | We are seniors compelled to urgent action) forced the government to release six reports completed at the beginning of last year regarding how climate change will affect our area and what kinds of planning are required.  The U.S. Republican presidential candidate has pledged “drill, baby, drill,” and in his earlier administration reduced government interventions into climate change issues. The government of Canada has introduced many measures, which have caused many complications in their relations with the provinces, and some decisions have been nullified by courts.

As we meet AMOC, it is the attitude of not only individuals, but that of governments, which will determine how we adapt to this and many possible changes in 2025.


We may have to change our lifestyle habits.  All the discussion I’ve read so far about energy needs, assumes we will keep doing everything we do now, and even more, thereby always needing more energy and other resources.  We may have to change some habits, so as to use less energy by reducing the need of power-hungry computer servers, local and distant travel, and demand for manufactured things.  We learned to change many habits during COVID (however begrudgingly) and learned how to do many things differently (or not do them for a while).  We learned to wait for some things, or simply not do them or procure them.  We may need to adapt habits to availability of energy, water, food, and our daily living.  An ethic of generosity and compassion will help us accept those changes.


I strongly advocate adopting this ethic for AMOC and thereafter and encourage people to insist that governments do so as well.  It is far better than letting fear, defensiveness, partisanship, and politics be at the front of our responses.  And if this ethic leads us to not wait and then respond, but think ahead and plan ahead, all the better for us.

1  Warning of a forthcoming collapse of the Atlantic meridional overturning circulation | Nature Communications

Physics-based early warning signal shows that AMOC is on tipping course | Science Advances

Interbasin and interhemispheric impacts of a collapsed Atlantic Overturning Circulation | Nature Climate Change

AMOC: What to know about the ocean current potentially collapsing (slate.com)

The crucial tipping point scientists say could cause Atlantic Ocean collapse – The Washington Post

2An important question indeed and one that relates more broadly to the topic of tipping points, which can have profound impacts on the climate system.

  • IPCC’s AR6 Working Group 1 Summary for Policymakers notes that, “Low-likelihood, high-impact outcomes could occur at global and regional scales even for global warming within the very likelyrange for a given GHG emissions scenario: The probability of low-likelihood, high-impact outcomes increases with higher global warming levels (high confidence). Abrupt responses and tipping points of the climate system, such as strongly increased Antarctic ice-sheet melt and forest dieback, cannot be ruled out (high confidence).” (p.27)
  • Regarding AMOC, the report finds that, “The Atlantic Meridional Overturning Circulation is very likelyto weaken over the 21st century for all emissions scenarios. While there is high confidence in the 21st century decline, there is only low confidence in the magnitude of the trend. There is medium confidence that there will not be an abrupt collapse before 2100. If such a collapse were to occur, it would very likely cause abrupt shifts in regional weather patterns and water cycle, such as a southward shift in the tropical rain belt, weakening of the African and Asian monsoons and strengthening of Southern Hemisphere monsoons, and drying in Europe.” (p.27)
  • But as Prof. Stefan Rahmstorf writes:
    • “It has long been my opinion that ‘very unlikely’, meaning less than 10% in the calibrated IPCC uncertainty jargon, is not at all reassuring for a risk we really should rule out with 99.9% probability, given the devastating consequences should a collapse occur.”
    • And: “Standard climate models probably underestimate the risk”, which he further explains in his blog (2023).

The Nature article (2023) did get a lot of attention (and some mis-reporting) and critiques.

Regarding the recent Science Advances article (2024), I also found this article in The Conversation by the study authors helpful:

  • “The big question – when will the Atlantic circulation reach a tipping point – remains unanswered. Observations don’t go back far enough to provide a clear result. While a recent study [i.e., the 2023 Nature article] suggested that the conveyor belt is rapidly approaching its tipping point, possibly within a few years, these statistical analyses made several assumptions that give rise to uncertainty.”
  • Here’s also a reaction to the study from Prof. Stefan Rahmstorf (2024).

On tipping points, the following may be of interest:

As for impacts on North America/Canada, if AMOC were to collapse:

  • studies suggest that North America could get a few degrees cooler (but maybe less than Europe)
  • Sea level rise could worsen and impact Atlantic Canada
  • For the Toronto region (and rest of NA/Canada), we may see changes in winter/extreme storm events, impacts on ecosystems and global food supply chains and other cascading impacts
  • More potential biophysical impacts can be found on p.125 in the Global Tipping Points (2023)


Glenn Brown was an ethics consultant with primary interest in corporate responsibility for environmental concerns including ethics standards throughout supply chains rt.

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