Friday, November 26, 2021

Anastassia Makarieva on the role of forests in Earth's climate


If you can, do spend half an hour to watch the talk that Anastassia Makarieva gave at the Technical University of Munich (TUM) on 24.11.2021.

It is not easy stuff if you are not familiar with the field of atmospheric water circulation, but it is worth making the effort. Anastassia and her colleagues are doing nothing less than revolutionizing the way we understand the role of forests in the ecosystem. Rather than being a passive entity for humans to make chairs and cricket bats, forests may actually be what makes life on Earth possible, they are part of the great planetary holobiont that uses forests to regulate itself. 

Thursday, November 18, 2021

The Secret of the Long Life of a Good Holobiont

Liliana Lippi, my mother in law, died last week at 101. You see her  in a picture taken for her 101th birthday, last July. with her two daughters and her son (on the left, my wife, Grazia). She also had four grandchildren and two great-granddaughters. What was the secret of her long life? Probably not a single factor, but perhaps the main one was that she managed to attain a certain harmony with the people and the things that surrounded her, as a good holobiont should do. 

I already wrote about Liliana's Longevity in a previous post published for her 100th birthday. Here is a longer and updated version.

Liliana Lippi was born in Florence, Italy, in 1920. She arrived into a completely different world from the one she left. When she came of age, in the 1930s, there were no TVs, no refrigerators, no supermarkets, no fast food, few homes had phones, very few people had cars. And her home had no central heating system: in winter she would sometimes wake up in the morning seeing that the water in the washbasin near her bed had frozen solid at the top. 

Her life as a young woman was typical of that age, when middle-class women, as she was, were supposed to be housewives and no more. She could cook, sew, clean, and perform other household skills. She never learned how to drive a car -- she couldn't even ride a bicycle. As most Florentines at that time, she couldn't swim and she was always a little afraid of the sea. No one remembers having ever seen her in a swimsuit. 

That doesn't mean her life wasn't rich in emotions and satisfactions. She had several suitors and the one who finally could touch her heart was a young Sicilian student who was studying at the Art Institute of Florence, close to where she lived. You may wonder how courting could take place in an age without telephones and social media: Liliana told me that the boy she eventually married would walk up and down along the street where she lived until she noticed him! You can find the same technique to get the attention of girls in Boccaccio's Decameron, written six centuries earlier! Probably, Sumerian boys would do exactly the same thousands of years ago. 

Liliana's sentimental life was adventurous. One reason was that, at the time, it wasn't so usual for a Florentine girl to have a Sicilian fiancĂ©. Southerners were often shunned in Florence, just like Africans are, nowadays. Consider that the family of the boy (Giovanni) was not rich, and you have a recipe for contrasts in the family. Liliana's father, Mario, was never happy about this prospective marriage, but one of the characteristics of Liliana's personality was that she was stubborn about her choices. She wanted that boy and she had him, despite all that happened, including the war starting, Giovanni being drafted and sent to fight in Africa, then coming back to Florence and being wounded at a leg in a gunfight among the factions battling in the civil war. 

Eventually, Giovanni and Liliana did manage to get married in 1946. Then, they both moved to Sicily over a slow steam train that took two days to travel from Firenze to the city of Messina, where Giovanni's parents lived. Liliana remembers Sicily as an exotic place: a sort of wonderland. She and Giovanni were met at the train station by Giovanni's relatives who had arranged their transportation using a traditional, brightly colored Sicilian cart pulled by a donkey. And the Sicilians, in turn, were awed by this Florentine girl whom they considered a princess, of a sort. 

It seems that Liliana had a good time in Sicily, the problem was that there was no job there for Giovanni and that the home where they were living hosted the whole family, Giovanni's parents, and his sisters and brothers. When Liliana got pregnant of her first child, they came back to Florence where they settled in the house that her grandfather had bought for the whole family. Giovanni worked as a woodcarver, a skill he had learned at the Art School, while Liliana was a housewife. She had children, grandchildren, and even great-grandchildren. Giovanni died in 2003 at 89, Liliana survived him for almost two decades, dying at 101 in peace at her home, in her bed, surrounded by her children. She had been living in that same home since 1929. 

Despite some problems typical of old age (mainly arthritis), Liliana lived a reasonably healthy life up to her last 2-3 weeks. Remarkably, up to the last moments, she showed no signs of dementia, so common with old people nowadays. Of course, she would forget things and sometimes lose track of the conversation, but 15 days before dying, she was still sewing without needing glasses. Up to the very last day, she recognized her children and she was obviously happy to have them close to her. 

So, what was Liliana's secret for such a long life? Diet, exercise, medicines? Or what?

Let's start with food. Among the things she never ate there was junk food: pizza, hamburgers, Chinese food (she didn't even know what Chinese food was), or soft drinks. She didn't drink alcohol, not even wine. About what she ate, hers was a relatively high-protein diet in the form of eggs, chicken and rabbit meat, and also the boiled meat used to prepare the soup, a habit reported to have scandalized the British travelers who visited Florence at the time of the "Grand Tour. She also loved the fat part of the meat, including the fat coming with prosciutto (ham). She also drank milk every day, in the morning and before going to bed. About carbohydrates, she ate bread, very rarely sweets, and she was also fond of the kind of Italian soup we call "minestra in brodo." Personally, I hate it but maybe should reconsider after seeing how well it worked with her! In terms of vegetables, Finally, she was not especially fond of vegetables, which always appeared cooked at her table-- she seemed to be somewhat suspicious of salads. In short, not a ketogenic diet, but surely not vegetarian.

What else? She didn't smoke, she drank a little coffee, but that was her only recreational drug. She had an active life, but she wouldn't even dream of "exercising" in a gym or running along the street. She did watch TV, a little, when she was free of the various chores at home. But she never was interested in the news or in politics. Not an intellectual, she was nevertheless a voracious reader of all kinds of books, newspapers, and magazines.  

In terms of medicines, she avoided them as much as possible. When she was in her 70s she was found to have very high blood pressure and her doctor had her taking the full spectrum of pressure-lowering drugs: beta-blockers, diuretics, and other stuff that I can't exactly classify. I don't know how effective these drugs were. In any case, she never took statins to reduce her cholesterol level which was supposed to be in the normal range. Or maybe not, I have no idea of when she last checked that, possibly 10 years ago or more. 

During the Covid period, her physician insisted to vaccinate her with the Pfizer thing, last spring. I don't think it had any effect, good or bad, we never had her tested for the coronavirus since she showed no symptoms of it. What I can tell you is that we never isolated her, never had her wear a mask, her relatives newer wore a mask when staying with her, and we never prevented her from seeing her great-granddaughters. She enjoyed their company a lot, nearly up to the last moments of her life.

In the end, I don't want to stretch too much the analogy with holobionts, but there is something in living a good and long life that has to do with attaining that kind of harmonious equilibrium that is the characteristic of holobionts. They are creatures living in symbiosis with each other in a non-hierarchical network. We humans can do that if we are well connected with the other humans surrounding us. Of course, there does not exist a perfect set of interactions but, on the whole, is the way we are built to live: part of the human social holobiont. 

Liliana surely was a good social holobiont. I told you that she was stubborn, but that was when it was about herself. With the others, she was very flexible, never trying to impose anything on anyone, accepting things as they came.  And she had a rich social life: her home was always open to relatives and friends coming for lunch -- she was the hub of a remarkable network of interactions among people. No one seems to remember her going mad at something or someone. Maybe this is the secret of a long life, maybe not. And so it goes. 

Here is Liliana for her 100th birthday. You see with her daughter (Grazia) granddaughter (Donata), and great-granddaughter (Aurora). All of them are daughters of the Goddess Gaia, connected over nearly one century of life, a snapshot of the great chain of beings that keeps turning and turning, and has been doing that for billions of years, and will keep doing that for many more years. 

Tuesday, November 9, 2021

Meeting the Goddess Gaia in a Supermarket!

Maybe this image is not so impressive as you would expect the Goddess of Earth, Gaia, to be. Still, it is impressive to walk into a supermarket and then, suddenly, be exposed to an epiphany of the Goddess herself. No doubt, it is her. Gaia, sometimes compassionate and merciful, and sometimes cruel and ruthless. She who rules the ecosystem, she who embodies the ecosystem, she who is the ecosystem. Gaia, the supreme holobiont, the ultimate living being, the apex of the great ecosystemic fractal, the product of billions of years of evolution. 

And there she is, smiling and at ease among the aisles of a suburban supermarket. Perhaps just the place where she should be as the Goddess of abundant life. 

Thursday, October 28, 2021

Anastassia Makarieva Speaks About the role of Forests in Protecting Earth's Climate


Anastassia Makarieva in a recent talk recommendsed the preservation of the natural forest holobiont:

International climate discourse mentions forests in two contexts: as carbon deposits and as renewable sources of materials and energy.

If implemented in global policies, this narrow view on forests can, contrary to expectations, worsen climate destabilization. Two crucial aspects are undervalued and understudied.

The first is the major role of forests as regulators of the various aspects of the water cycle, including cloud cover (a major source of climate uncertainties) and ocean-to-land and transcontinental transport of atmospheric moisture.

The second is the difference in the environmental functions of primary forests, largely unperturbed by anthropogenic activities, versus exploited tree stands. While the former have evolved to maximize environmental homeostasis, the latter were selected to maximize economic productivity. The two cannot be maximized simultaneously.

Successful strategies of climate change mitigation should prioritize preservation of still extant self-sustainable natural forests for humanity to continue benefiting from their climate stabilization potential.

Tuesday, October 19, 2021

How Will our Descendants Remember us?


You see, there is a succession process for forest recovery. We first have shrub grasses after some disturbance like fire, then it takes time for that to be replaced by trees. So if we are lucky our grand grandchildren will be walking in such forest, so this dimension should also be stressed. We are working for the future we are not just securing for ourselves some two dozens years of better comfort. Rather, we send a message through centuries such that people will remember us and walking into this forest along the brookes and rivers they will remember us with gratitude for our consciousness and dedication.

Anastassia Makarieva 

Thursday, September 30, 2021

The Memesphere as a Holobiont (the Mousetrap Experiment)


Ilaria Perissi with our mechanical model of a fully connected network. You may have seen this set-up as a way to demonstrate the chain reaction that takes place in nuclear explosions. It is simulated here with 50 mousetraps and 100 wooden balls. When you trigger one mousetrap, it releases two balls that may go trigger two more mousetraps, and the reaction rapidly flares up and then subdues when it runs out of mousetraps.  And here is what happens

This experiment is a lot of fun (apart from the pain when one trap snaps as you are loading it). But it is not just about nuclear reactions: we engaged in this demonstration because we wanted to show that what happens with the mousetraps is much more general than that. What you have here, is a kind of network that's called "fully connected." The traps are nodes of the network, the balls are elements that trigger the connection between nodes. It is a kind of communication based on "enhanced" or "positive" feedback.

Imagine that the traps oil wells. Then, the balls are the energy created by extracting the oil. And you can use that energy to dig and exploit more wells. The result is the Hubbert curve, nothing less! We found this kind of curve for a variety of socioeconomic system, from mineral extraction to fisheries (for the latter, you can see our (mine and Ilaria's) book "The Empty Sea.

But there is more: imagine that traps are people while the balls are memes. Then what you are seeing is a model of a meme going viral in the Web. It works exactly like that: ideas (also called memes) flare up in the Web when they are stimulated it is the power of propaganda that affects everybody.

It is an intelligence because it can amplify a signal -- that's the way it reacts to an external perturbation. You could see the mousetraps as an elaborate detection system for stray balls. But it can only flare up and then decline. It can't be controlled. That's the problem with our modern propaganda system that exists in the memesphere. It is dominated by memes flaring up out of control.  The main actors in this flaring are those "supernodes" (the Media) that have a huge number of long-range connections. That can do a lot of damage: if the meme that goes out of control is an evil meme and it implies, say, going to war against someone, or exterminating someone. It happened and keeps happening again as long as the memesphere is organized the way it is, as a fully connected network.

Now, let's go to the holobiont part: you could call the mousetrap network a holobiont because holobionts are non-hierarchical networks of entities that communicate with each other. Yes, but this kind of holobiont is not a good holobiont. That is, it exists in nature. Think of a flock of birds foraging in a field. One bird sees something suspicious, it flies up, and in a moment all the birds are flying away.

It is a chain reaction. In a sense, the flock is endowed with a certain degree of intelligence. It can process a signal and act on it. You can see in the figure the measurement of the number of flying birds. It is a logistic function, the integral of the bell-shaped curve that describes the flying balls in the mousetrap experiments

But holobionts in Nature are not normally fully connected. Their connections are short-range, and signals travel more slowly through the network. It is often called "swarm intelligence" and it can be used to optimize systems. Swarm intelligence does transmit a signal, but it doesn't amplify it out of control, as a fully connected network does, at least normally. It is a good control system: bacterial colonies and ant colonies use it. Our brains much more complicated: they have short range connections but also long range ones and probably also collective electromagnetic connections. 

All that means we are stuck with a memesphere that's completely unable to manage complex systems. And yet, that's the way the system works. It depends on these waves of out-of-control signals that sweep the web and then become accepted truths. Those who manage the propaganda system are very good at pushing the system to develop this kind of memetic waves, usually for the benefit of their employers. 

Can the memesphere be re-arranged in a more effective way -- turning it into a good holobiont? Probably yes. Holobionts are evolutionary entities that nobody ever designed. They have been designed by trial and error as a result of the disappearance of the unfit. Holobionts do not strive for the best, they strive for the less bad. It may happen that the same evolutionary pressure will act on the human memesphere. 

The trick should consist in isolating the supernodes (the media) in such a way to reduce their evil influence on the Web. And, lo and behold! Haven't you heard of how many people say that they don't watch TV anymore, they don't connect to CNN, and the like? That's exactly the idea. Do that, and things will be better for everyone. 

Sunday, August 22, 2021

The Story of Moby Dick Told by the Whale



by Ugo Bardi

Whales are the largest holobiont of this planet. Here myself and my coworker, Ilaria Perissi, engage in a little theatrical piece where Moby Dick himself tells his story. How he met that weird two-tailed creature whose name he learned to be something like Heyhab. And how in a terrible battle, he was forced to kill this enemy, although not willing to do that. And how, wounded, he sunk to the bottom where he met the spirits of his ancestors who told him of the sad destiny of the two-tails, land creatures destined to perish because they couldn't limit their greed. 

The story is an spinoff of our book "The Empty Sea" published in 2020. 



Wednesday, August 11, 2021

Holobiont: An Introduction to the Concept


God must be incredibly fond of holobionts, since He created so many of them. And He (or She) may be a holobiont as well. 


It once happened, that the other members of a man mutinied against the stomach, which they accused as the only idle, uncontributing part the whole body, while the rest were put to hardships and the expense of much labour to supply and minister to its appetites. The stomach, however, merely ridiculed the silliness of the members, who appeared not to be aware that the stomach certainly does receive the general nourishment, but only to return it again, and redistribute it amongst the rest. (Plutarch, “Life of Coriolanus”)

In guerrilla warfare, select the tactic of seeming to come from the east and attacking from the west; avoid the solid, attack the hollow; attack; withdraw; deliver a lightning blow, seek a lightning decision. When guerrillas engage a stronger enemy, they withdraw when he advances; harass him when he stops; strike him when he is weary; pursue him when he withdraws. In guerilla strategy, the enemy's rear, flanks, and other vulnerable spots are his vital points, and there he must be harassed, attacked, dispersed, exhausted and annihilated. (Mao Zedong, 1937)


Maybe it happened to you to spend hours waiting for a flight in a busy international airport. You are blocked there and, after having had enough coffee to make you walk like a shuffle dancer, you have nothing else to do but to wander aimlessly from one shop to another. Bookstores offer something to read but, perhaps more interestingly, they give you a chance to get hints of what other people read. A rare chance of a glimpse of other people’s minds in our busy world.

So, what are people reading, nowadays? A lot of magazines and books that you can find in an airport bookstore are about the two primeval human interests: food and sex (the latter usually not so explicitly presented as the former). Apart from that, you find plenty of material on everyday matters: cellphones and other electronic gadgetry, cars, travel, religion, and more. In addition, the typical international airport bookstore has a section on how to deal with other people. They are self-help books that claim to train you on how to manage your relationship with your coworkers, your friends, and your family.

Evidently, many people find that dealing with others is a difficult matter, enough that they need help and guidance. It is a little strange, because we are all the result of at least three hundred thousand years of evolution of the species called homo sapiens. Our ancestors survived because they were good enough at creating and keeping relationships with their neighbors that would help them in times of need. But, perhaps, living in the modern society, so bewilderingly complicated, is more difficult than living in a tribe of hunters and gatherers.

Are these books really useful? There are good reasons to be skeptical. The books often seem to be a mishmash of this and that, they are not quantitative, not based on solid theories, not related to experimental evidence. The latest fad in management theory is a book titled “Reinventing Organizations.” The title may be interesting, but the substance of the book may be criticized. According to the author, good management has something to do with a hierarchy of colors. Infrared is primitive and bad, while the shade of blue called “teal.” is modern and good. Why that should be the case, is not explained anywhere in the book. That doesn’t mean to disparage a book that may have good points, but maybe you will agree with us that such a classification is a little arbitrary, to say the least.

So, can we make some order in this chaos? Maybe yes. And we can try to do that using the concepts of “holobiont” and the related one of “empathy.” The idea is that human societies of all kinds are the result of evolutionary pressure and that those you find in our world exist because there is a reason for them to exist. Just as biological holobionts are a feature of the biosphere, there exist societal holobionts, a feature of the human social sphere. Societal holobionts are an example of “Complex Adaptive Systems,” (CAS) that is, systems that develop a condition of stability called “homeostasis” and that tend to maintain it when perturbed. These holobionts are virtual, unlike the microbes in your gut. So, we may also call them “virtual holobionts.

Let’s start with an example. The simplest kind of human organization is the least organized one: the crowd (you can also call it a “mob” or a “band”). It has no leaders, no hierarchy, no specializations. Yet, you recognize a crowd when you see one. Perhaps the first time when crowds were dealt with as something worth of interest was with the book by the French author Gustave le Bon “Psychologie des Foules, (1895) that was translated into English as « The Crowd, A study of the Popular Mind. ». Reading it today, you would probably judge it to be a poorly made political pamphlet. And, indeed, it had a certain success with right wing politicians. Nevertheless, it was one of the first studies of complex systems in sociology.

Crowds are not just a feature of human society; equivalents exist with many animal societies. They go with different names: storms (or flocks) of birds, schools of fish, herds of sheep, prides of lions, and there are other examples (for instance, a bacterial mat). In any case, they share the same characteristics: they are loosely bonded groups of individuals who may stay together for a while and dissociate back into single units at any time. But, as long as they exist, crowds (just like all human organizations) are groups of people linked together.

Let’s go deeper into the matter. If a crowd is an organization, albeit the simplest possible one, it could be described using those “organizational charts” that purport to describe how a company is organized. These charts are maps designed to describe the hierarchical territory of the company. They have also been used to describe the organization of entities such as the Sicilian Mafia and Drug Cartels. They can also map the relationships in a band of Chimps or Bonobos.

But an organizational chart can be much more than simply a static map that tells you whom you should see, for instance, to organize a shipment or to order a supply of something (or, if you are a male bonobo, where to find an available female). The chart tells us a lot on how the organization works and also something about how it developed over time. It is part of the field called “management science.”

A good way to interpret organizational charts is to see them as networks.  Network science is a relatively recent development that derives from a field called “graph theory.” It is something that deals with how points in space (called “vertices”, plural of “vertex”) are arranged in space in terms of pairwise links with other vertices. You see an example of a graph in the figure


You note that there are 6 vertices (also called “nodes”), each one connected to its nearest neighbors. In this case, the connections (“links” or “edges”) are not directional, but that may be explicit in some kinds of graphs. It may also be possible that a node is connected to several other nodes.

Graph theory is a branch of pure mathematics, and it deals only with geometric arrangements. Instead, “Network theory” (or “network science”) deals with applications of graph theory to the real world. In this case, the nodes are real entities: people, departments, servers, combat units, and much more. Also, the links are related to real methods of information exchange: documents, orders, radio signals, fiber optics, and more.

Armed with this a basic knowledge, let’s go back to the example of the crowd. The simplest crowd network we may imagine is one formed of just three people (or bonobos). Here is the graph.

You see that each node (one member of the group) is connected to his/her neighbors. Information flows from each node to the closest one. There is no hierarchy: all the nodes are the same, which is one of the characteristics of crowds/bands/flocks, etc. You can say that the relationship between the elements of this crowd is horizontal, as opposed to the vertical kind seen in hierarchical organizations such as companies, armies, etc, as we’ll see later on.

We can expand the graph to describe a system where there are more than three nodes. You see below several possible arrangements


In the first case (a), each node is connected only to its two nearest neighbors. It is a little like being squeezed in the crowd in a busy subway station – if you have ever visited Tokyo, you know what that means. In such a condition, you can only move together with the crowd, and you don’t see anything more than your nearest neighbors.

Things may be more complicated than that and, in the other images, you see how nodes may be connected to more nodes than just their near neighbors. In case (b) each node is in contact with 4 neighbors. It is still a crowd, but not so dense as case (a). Case (c) shows the possibility of long-range connections for some of the nodes. Maybe someone in the crowd is in contact with a friend in the same crowd, but using a cell phone. Case (d) refers to a kind of network that is called “fully connected,” meaning that every node is connected to every other node. In the real world, it is a rare occurrence, even though it may exist for very small networks. For instance, the 3-nodes example seen before is a fully connected network. All these arrangements are non-hierarchical, or “horizontal”.

All these examples are special cases where all nodes are not only identical, but have all the same number of connections. In most cases, this is not true and each element is connected to a different number of nodes.

The figure illustrates the variations in the number of connections. The left examples shows a network where every node has 4 links. The central one is called the “small world” network. Most connections are to the close neighbors, but some are long range. The right one has more links, randomly arranged, but it is not fully connected.

The reason why the central diagram is called “small world” deserves some explanation. It has to do with the distance (in terms of number of links) between nodes. In this kind of network, it grows proportionally to the logarithm of the number of nodes, so it is not as large as it would be if you had to crawl every node, one after the other, to reach a node on the other side of the circle. In a small world network, if you wanted to contact, say, the president of the United States, it is said that you need to go through no more than six steps, starting with a person you are in contact with. It is not exactly like this, but it is a long story. Let’s just say that it is a “natural” way in which networks tend to arrange themselves.

You may say that the number of connections provide an embryonic form of hierarchy in these networks. If knowledge is power, then more connections mean more knowledge and therefore more power. This hierarchical relationship is especially evident on the Internet. A site such as, say, the CNN is defined by an URL (Uniform Resource Locator) just like any other blog or site on the web. But the CNN has a hugely larger number of connections than the average web site and there is no doubt that it has much more power in terms of pushing memes in the memesphere. But, overall, these systems remain horizontal in the sense that CNN doesn’t have the possibility to order to bloggers what to publish or not to publish in their sites (so far). Many internet “bubbles” are relatively egalitarian, although some nodes (people or groups) carry more weight than others.

These non-hierarchical networks are the general representation of the concept of “holobiont.” The way Lynn Margulis described holobionts was in terms of a group of individuals of different species that moved together in the condition called “symbiosis,” a mutual relationship that provides advantages to all the creatures engaged in it. Holobionts imply an intricate network of relationships among the various member of the community, but no fixed hierarchical structure although, obviously, some members have more prestige and power than others. Margulis was thinking of microbial communities, but we can enlarge the definition to ensembles of animals (if you prefer the formal term, we could say “ensembles of metazoa”). But the organizational diagrams in the form of circles could describe them nicely.

But what is the advantage for an individual to be part of a crowd? (or a flock, or a herd, or a pride?). Are these individuals in a symbiotic relationship? Yes, they are, by all means. Symbiosis is a condition of mutual help that in systems is generated by the way the system is organized, NOT by the good will of the individuals (it would be hard to speak of good will among bacteria, for instance). The beauty of symbiosis is that all the creatures engaged in it strive for their own benefit but, in the process, they manage to benefit every other creature.

Said in this form, it sounds as an extreme version of Adam Smith’s “invisible hand,” still today the basis of liberalism as a political ideology. The idea of the invisible hand has been much ridiculed over the years (you know how many economists it takes to replace a light bulb? None, it is done by the invisible hand!). But the idea is good if it is applied with a grain of salt.

Ugo Bardi (yours truly) and his coworker Ilaria Perissi discussed this issue in a paper that they titled “The Sixth Law of Stupidity,” where we argued that the opposite of stupidity is when human beings enter in a condition of symbiosis with other people. We also argued that stupidity is temporary while intelligence is long term, which means that people tend to learn from their mistakes. Even creatures not especially known for their large brains (say, bacteria) tend to learn from their mistakes – and those who don’t learn are eliminated by natural selection.

So, humans in a crowd are in a symbiotic relationship even though they may not recognize that. The crowd offers a certain refuge to its members. Maybe for humans it is not a general rule: when you are being shelled or shot, the worst possible idea would be to form a crowd that would attract the enemy fire. But, if you look at crowds in the animal kingdom, their utility is evident. Have you ever observed the behavior of a storm of birds? You may see them landing on a patch of grass to feed. If you get close, one of the birds may see you, be scared, and fly off. Immediately, the nearby birds will be alerted and fly off, too. In a moment, the whole storm will be flying away. In this case, the crowd (the storm) offers a danger-detection service that a single bird cannot have. 

More in general, a storm/flock/herd/crowd offers statistical protection. A predator is not interested in destroying the whole flock, only at capturing as many individuals as it needs. So, if the flock is large, the probability for an individual to be captured is low. Of course, humans tend to destroy even things they don’t need, but this is part of the 6th law of stupidity .

We have now a definition of how a holobiont is structured according to the network theory. We may want to represent it as a triangle and, thinking about that, there could be a relation with the triangular symbol “the eye of God.”

And, indeed, a triangle can be seen as the icon for both a holobiont and God (or the Goddess Gaia). But let's not go into theology, this introduction should be enough to understand what a holobiont is. The next step is the concept of hierobiont, a network partly or completely structured in a hierarchical manner. But we'll see that in another post.

Tuesday, July 27, 2021

When the Ice Will be Gone: The Greatest Change Seen on Earth in 30 Million Years.



An image from the 2006 movie "The Meltdown," the second of the "Ice Ages" series. These movies attempted to present a picture of Earth during the Pleistocene. Of course, they were not supposed to be paleontology classes, but they did show the megafauna of the time (mammoths, sabertooth tigers, and others) and the persistent ice, as you see in the figure. The plot of "The Meltdown" was based on a real event: the breakdown of the ice dam that kept the Lake Agassiz bonded inside the great glaciers of the Laurentide, in the North American continent. When the dam broke, some 15,000 years ago, the lake flowed into the sea in a giant flood that changed Earth's climate for more than a thousand years. So, the concept of ice ages as related to climate change is penetrating the human memesphere. It is strange that it is happening just when the human activity is pushing the ecosystem back to a pre-glacial period. If it happens, it will be the greatest change seen on Earth in 30 million years


We all know that there is permanent ice at Earth's poles: it forms glaciers and it covers huge areas of the sea. But is it there by chance, or is it functional in some way to Earth's ecosphere? 

Perhaps the first to ask this question was James Lovelock, the proposer (together with Lynn Margulis) of the concept of "Gaia" -- the name for the great holobiont that regulates the planetary ecosystem. Lovelock has always been a creative person and in his book "Gaia: A New Look at Life on Earth"  (1979) he reversed the conventional view of ice as a negative entity. Instead, he proposed that the permanent ice at the poles was part of the planetary homeostasis, actually optimizing the functioning of the ecosphere. 

Lovelock was perhaps influenced by the idea that the efficiency of a thermal engine is directly proportional to the temperature differences that a circulating fluid encounters. It may make sense: permanent ice creates large temperature difference between the poles and the equator and, as a consequence, winds and ocean currents are stronger, and the "pumps" that bring nutrients everywhere sustain more life. Unfortunately, this idea is probably wrong, but Lovelock has the merit to have opened the lid on a set of deep questions on the role of permanent ice in the ecosystem. What do we know about this matter?

It took some time for our ancestors to realize that permanent ice existed in large amounts in the high latitude regions. The first who saw the Northern ice sheet was probably Eric the Red, the Norwegian adventurer, when he traveled to Greenland around the year 1000. But he had no way to know the true extent of the inland ice, and he didn't report about them.

The first report I could find on Greenland's ice sheet is the 1820 "History Of Greenland", a translation of an earlier report (1757) in German by David Crantz, where you can find descriptions of the ice-covered inland mountains. By the early 20th century, the maps clearly showed Greenland as fully ice-covered. About Antarctica, by the end of the 19th century, it was known that it was also fully covered with a thick ice sheet. 

Earlier on, in the mid 19th century, Louis Agassiz had proposed a truly revolutionary idea: that of the ice age. According to Agassiz, in ancient times, much of Northern Europe and North America were covered with thick ice sheets. Gradually, it became clear that there had not been just one ice age, but several, coming and going in cycles. In 1930, Milutin Milankovich proposed that these cycles were linked to periodic variations in the insulation of the Northern Hemisphere, in turn caused by cycles in Earth's motion. For nearly a million years, Earth was a sort of giant pendulum in terms of the extent of the ice sheet. 

The 2006 movie "An inconvenient truth" was the first time when these discoveries were presented to the general public. Here we see Al Gore showing the temperature data of the past half million years.

An even more radical idea about ice ages appeared in 1992 when Joseph Kirkschvink proposed the concept of "Snowball Earth." The idea is that Earth was fully covered by ice at some moment around 700-600 million years ago, the period appropriately called "Cryogenian."

This super-ice age is still controversial: it will never be possible to prove that every square kilometer of the planet was under ice and there is some evidence that it was not the case. But, surely, we are dealing with a cooling phase much heavier than anything seen during relatively recent geological times.

While more ice ages were discovered, it was also clear that Earth was ice-free for most of its long existence. Our times, with permanent ice at the poles, are rather exceptional. Let's take a look at the temperatures of the past 65 million years (the "Cenozoic"). See this remarkable image (click to see it in high resolution)

At the beginning of the Cenozoic, Earth was still reeling after the great disaster of the end of the Mesozoic, the one that led to the disappearance of the dinosaurs (by the way, almost certainly not related to an asteroidal impact). But, from 50 million years ago onward, the trend has been constant: cooling. 

The Earth is now some 12 degrees centigrade colder than it was during the "warmhouse" of the Eocene. It was still ice-free up to about 35 million years ago but, gradually, permanent ice started accumulating, first in the Southern hemisphere, then in the Northern one. During the Cenozoic, Earth never was so cold as it is now.

The reasons for the gradual cooling are being debated, but the simplest explanation is that it is due to the gradual decline of CO2 concentrations in the atmosphere over the whole period. That, in turn, may be caused to a slowdown of the outgassing of carbon from Earth's interior. Maybe Earth is just becoming a little older and colder, and so less active in terms of volcanoes and similar phenomena. There are other explanations, including the collision of India with Central Asia and the rise of the Himalaya that caused a drawdown of CO2 generated by the erosion of silicates. But it is a hugely complicated story and let's not go into the details.

Let's go back to our times. Probably you heard how, just a few decades ago, those silly scientists were predicting that we would go back to an ice age. That's an exaggeration -- there never was such a claim in the scientific literature. But it is true that the idea of a new ice age was floating in the memesphere, and for good reasons: if the Earth had seen ice ages in the past, why not a new one? Look at these data:

These are temperatures and CO2 concentrations from the Vostok ice cores, in Antarctica (you may have seen these data in Al Gore's movie). They describe the glacial cycles of the past 400,000 years. Without going into the details of what causes the cycles (solar irradiation cycles trigger them, but do not cause them), you may note how low we went in both temperatures and CO2 concentrations at the coldest moments of the past ice ages. The latest ice age was especially cold and associated with very low CO2 concentrations. 

Was Earth poised to slide down to another "snowball" condition? It cannot be excluded. What we know for sure is that during the past million years or so, the Earth tethered close to the snowball catastrophe every 100,000 years or so. What saved it from sliding all the way into an icy death?

There are several factors that may have stopped the ice from expanding all the way to the equator. For one thing, the sun irradiation is today about 7% larger than it was at the time of the last snowball episode, during the Cryogenian. But that may not have been enough. Another factor was that the cold and the low CO2 concentrations may have led to a weakening -- or even to a stop -- of the biological pump in the oceans and of the biotic pump on land. Both these pumps cycle water and nutrients, keeping the biosphere alive and well. Their near disappearance may have caused a general loss of activity of the biosphere and, hence, the loss of one of the mechanisms that removes CO2 from the atmosphere. So, CO2 concentrations increased as a result of geological emissions. Note how, in the figure, the CO2 concentration and temperatures are perfectly superimposable: the reaction of the temperature to the CO2 increase was instantaneous on a geological time scale. Another factor may have been the desertification of the land that led to an increase in atmospheric dust that landed on the top of the glaciers. That lowered the albedo (the reflected fraction of light) of the system and led to a new warming phase. A very complicated story that is still being unraveled. But how close was the biosphere to total disaster? We will never know.

What we know is that, 20 thousand years ago, the atmosphere contained just 180 parts per million (ppm) of CO2 (today, we are at 410 ppm). That was close to the survival limit of green plants and there is evidence of extensive desertification during these periods. Life was hard for the biosphere during the recent ice ages, although not so bad as in the Cryogenian. Lovelock's idea that permanent ice at the poles is good for life just doesn't seem to be right.

Of course, the idea that we could go back to a new ice age was legitimate in the 1950s, not anymore as we understand the role of human activities on climate. Some people maintain that it was a good thing that humans started burning fossil hydrocarbons since that "saved us from a new ice age." Maybe, but this is a classic case of too much of a good thing. We are pumping so much CO2 into the atmosphere that our problem is now the opposite: we are not facing an "icehouse Earth" but a "warmhouse" or even a "hothouse" Earth. 

A "hothouse Earth" would be a true disaster since it was the main cause of the mass extinctions that took place in the remote past of our planet. Mainly, the hothouse episodes were the result of outbursts of CO2 generated by the enormous volcanic eruptions called "large igneous provinces." In principle, human emissions can't even remotely match these events. According to some calculations, we would need to keep burning fossil fuels for 500 years at the current rates to create a hothouse like the one that killed the dinosaurs (but, there is always that detail that non linear systems always surprise you . . .)

Still, considering feedback effects such as the release of methane buried in the permafrost, it is perfectly possible that human emissions could bring CO2 concentrations in the atmosphere at levels of the order of 600-800 ppm, or even more, comparable to those of the Eocene, when temperatures were 12 degrees higher than they are now. We may reach the condition called, sometimes, "warmhouse Earth."

From the human viewpoint, it would be a disaster. If the change were to occur in a relatively short time, say, of the order of a few centuries, the human civilization is probably toast. We are not equipped to cope with this kind of change. Just think of what happened some 14,500 years ago, when the great Laurentide ice sheet in North America fragmented and collapsed. (image source) (the 2006 movie "Meltdown" was inspired exactly by this event). Earth's climate went through a series of cold and warm spells that is hard to think we could survive. 


Human survival concerns are legitimate, but probably irrelevant in the greater scheme of things. If we go back to the Eocene, the ecosystem would take a big hit during the transition, but it would survive and then adapt to the new conditions. In terms of life, the Eocene has been described as "luxuriant." With plenty of CO2 in the atmosphere, forests were thriving and, probably, the biotic pump provided abundant water everywhere inland, even though the temperatures were relatively uniform at different latitudes. A possible mental model for that period is the modern tropical forests of Central Africa or Indonesia. We don't have data that would allow us to compare Earth's productivity today with that of the Eocene, but we can't exclude that the Eocene was more productive in terms of life. Humans might well adapt to this new world, although their survival during the transition is by no means guaranteed. 

Again, it seems that Lovelock was wrong when he said that ice ages optimize the functioning of the biosphere. But maybe there is more to this idea. At least for one thing, ice ages have a good effect on life. Take a look at this image that summarizes the main ice ages of Earth's long history

 (image source)

The interesting point is that ice ages seem to occur just before major transitions in the evolutionary history of Earth. We don't know much about the Huronian ice age, but it occurred just at the boundary of the Archean and the Proterozoic, at the time of the appearance of the Eucaryotes. Then, the Cryogenian preceded the Ediacaran period and the appearance of multicellular life that colonized the land. Finally, even the evolution of the Homo Sapiens species may be related to the most recent ice age cycle. With the cooling of the planet and the reduction of the extent of forested areas, our ancestors were forced to leave the comfortable forests where they had lived up to then and take up a more dangerous lifestyle in the savannas. And you know what it led to!

So, maybe there is something good in ice ages and, after all, James Lovelock's intuition may have hinted at an important insight in how evolution works. Then, there remains the question of how exactly ice ages drive evolution. Maybe they have an active role, or maybe they are simply a parallel effect of the real cause that drives evolution, quite possibly the increasing concentration of atmospheric oxygen that has accompanied the biosphere over the past 2.7 billion years. Oxygen is the magic pill that boosts the metabolism of aerobic creatures -- what makes possible creatures like us. 

In any case, it is likely that ice ages will soon be a thing of the past on planet Earth. The effect of the human perturbation may be moderate and, when humans will stop burning fossil hydrocarbons (they have to, one day or another) the system may reabsorb the excess CO2 and gradually return to the ice age cycles of the past. That may occur in times of the order of at least several thousand years, possibly several tens of thousands. But the climate is a non-linear system and it may react by reinforcing the perturbation -- the results are unknowable. 

What we know for sure is that the cycle of Earth's ecosystem (Gaia) is limited. We still have about 600 million years before the sun's increasing brightness takes Earth to a different condition: that of "wet greenhouse" that will bring the oceans to boil and extinguish all life on the planet. And so it will be what it will have to be. Gaia is long-lived, but not eternal.


Ugo Bardi is a member of the Club of Rome, faculty member of the University of Florence, and the author of "Extracted" (Chelsea Green 2014), "The Seneca Effect" (Springer 2017), and Before the Collapse (Springer 2019)