 Prihledaj pa. Prihledaj da... Kaj je nalegi nalegi se, ni spikr, ni nalegi. Dobro. Kaj pa se zelo razstavimo, da smo se vse na zelo obježenih, in da smo zelo zelo zelo zelo, da smo se zelo zelo zelo zelo zelo zelo zelo zelo zelo. Ok? Ok, da se možemo. Zdaj smo biti ljudi, zato smo začali s Louis Bettenkord. Zdaj smo počkali o urbani systemu. Čakaj. Čakaj. Čakaj. Čakaj. Čakaj. Čakaj. Čakaj. Čakaj. Čakaj. Čakaj. Čakaj. Čakaj. Čakaj. Čakaj. Čakaj. Čakaj. Čakaj. Čakaj. Čakaj. Čakaj. Čakaj. Čakaj. Čakaj. Čakaj. Čakaj. Čakaj. Čakaj. Čakaj. Čakaj. Čakaj. Čakaj. Čakaj. Čakaj. Čakaj. Čakaj. Čakaj. Čakaj. in bomo vsi srečočen, ali sem vsečočen v tem, saj je našličan, ki so prejzapravljati. Tukaj tudi zvok sem bi ovo počišila, ko je mergaj v srečnih institutih, ki sem je v srečnih institutih, ki sem vsi način, však v Chicagou. Iga vseč je však predstavila v samom vsičnih iskudva in tukaj vsečnjeh in tišnje, kaj je tudi v zelo, počin je to vsečno. Zato sam je posledilo bomo to zelo. Pozincaj da sem početila video z nekočnjih citi, ki se zelo, kaj je ko je. Zato, kaj je komplikato in kompleks, ki so vzelo, nekaj da se početil, je vsega izgleda način izgleda način in vsega. Vsega je to zelo energijnej zelo, kaj mi so zelo. In nekaj do��iliین za premač Nebo in zelo spetaljne operacije in zelo vzdučno in minučí. To so nekaj način, in rezovst, in rezovst novoril enokaj soldiersi, neko so najbolj, in tukaj počutiv imati rezov Sloven及 in izgledati kvaliti. Sva je se na spetu počunja. Vse, koni, je to in tukaj počutiva. Zato sem videtil v Avstilu, vših šikagov, od 5 nekaj odelj, in vseveda je dan delalov del. Vneš sem, je to zelo ovega. The workshops are also in a good for the residents here. In University of Chicago has a relatively new university here. It started in the end of the nineteenth century, in a place that was new and at the margins of scholarship. It recreated many fields in its own way and in many schools of this and that in Chicago. One of the most important schools is the school of Urban Sociology. ki je to zame učinila, če je to vstajalo urvenstvih ziv, in se je zelo pošlišljene in kohli se je zelo pošlišljeni. Dozno se je zelo pošlišljeni in kohli se je zelo pošlišljeni, zelo pošlišljeni in kohli se je zelo pošlišljeni, zelo pošlišljeni in informacije in toj najbolji metafor, da je zelo pošlišljeni v samih časem, je to zelo na nožno, je to včinila na nožno, nesel je Henry Calds, je to nečen odgašan, je to professor Bodany The same building I occupy now in my faculty position. And he termed ecology into English but at the same time was adopted by people studying cities. So that's sort of an interesting resonance. And so what we do now is obviously bringing a lot of these ideas to the 21st century, which means that we study human societies that are urbanizing, but also that we bring modeling and data and principle theory to understand these very complex environments. So I have a lot of fun, cos I got to go all over the world and visit amazing places, in mn History of the Lessons in transformation. Most of the time it's a hopeful experience, because you see transformations very quick in many societies. Transformation that is generating development, human development. I'll tell you more later. But also creating challenges sustainability. So this is kind of what we do, we can look at the web page. And part of what I will tell you today W catastrophe university Chicago, on urban science had to be about urban science because of the what the 있나 stands, but sustainable development is what's important here. And so I've been trying in this context, so I teach, sort of, the main class, that the students need to take to get the certificate, they also do a project, but part of the problem has been how do we approach this story of sustainability in keh mon developer in a principled way, in a way that's generative, synthetic, but also speaks to positive, but it must in tačne objevtva se se tako povodila nekaj na vsem, a kot nešto način ozvodilji je inorma. Tukaj je zelo všeč normativno zdaj, hvalječ in vse objev, in tudi za mali vse zelo, da se prišli vse vse objevitve tačne pravdične, je sreč nekaj začine, ki so tukaj tudi se rejimamo, pomega, da nekaj, kako jaz način zelo povodila, so je bilo način začin začin začin začin. Zelo pa nečin začin začin začin. So ampak zelo, Tako, to je zelo z bistrona, čedaj z tudi dve, ki smo s Sekuvala, da je sem considela, da sveš ni drž almost na počri, ki v njega tudi se omdat dojede na počriom. Pover tudi se dar jaj zaradi. Kaj so ni sreč nekaj 경šči, jaz je to izgleda kaj pri inrlje z dvenstvo junij. To je počr jo dvanje. To je zelo zelo začet, dativne. In začem, taj je povedan. ki je Christmas Eve 1968, pa je to, da je težko, so je Christmas prezident na zelo. In zelo, da je to izgleda vzelo, je to je vzelo, da je težko težko technologične in vzelo, da je to je vzelo. Maslje in vzelo, da je to vzelo, je bil se početno vzelo, da je zelo se inštela vzelo, zelo se je izgleda, da je to izgleda, da je to vzelo, da je to vzelo, da je to izgleda, da je to zelo, da je to izgleda, v ročnih, da objah nekaj polidilo, gledaj je pozvečujemo aba, prej se, ki so pozvečujemo, in vsev boj, ko je pošlega in več več, in da se je tudi vera in 1968 včilj, in je pošlega pošlega. Spodobno, da bomo pošlega, je to pošlega in kaj je, je to pošlega, in je to pošlega, tako čak je del včelj način, neko se pošlega nekaj z 10 milijetnih, včelj nekaj pošlega. Je to, da mu se pošlega, To je nekaj in presvektiv, ki je tako inživno. Vse je, da je tudi se sp indexite, ki je tudi terčak in tako, nekaj prijevhabi na kroz, ki se pogledaj, ali je prijevhabi. In zelo bo ? ki začati, ki začayamo brane, načinem sem više mogu povisiti problem, načine da postojo nešta z strejstvimi in srednimi institučni vzup. In srednji se neštje. Vse zelo nešta se s edirje in v težki ali s tudi. ti je vse danes samozren je tudi ter v povoljtvane drugih dylocjih, če ustavimo naredne umjernje drugih populacijo v razlih, bolj nekaj dobroober svobatne. In nekaj dobroPER nekaj dobrober svobatne. En jas odložite povoriti, da bomo so bila zapolni, prišli, da je bilo zelo. To je bilo, da se, tako, mi je zdajno, In tudi se površila, da je zelo v jaloj, v zeloj, zelo, da je prijeljno počet, da je to počet, da je to prijeljno počet. Počet je, da se počet je začnje, je zeloj, vod, je energija, je zeloj počet, je zeloj počet, je včet način način in včet način način način način način. In tudi da včet način včet začnje, tako, pričenje, včet način in karban, tako, počet način, plastike in včetnih, We know that polluting the world. As the world developed, as population has grown, as the world urbanized, these flows are beginning worse and worse in the sense of pollution. And so a lot of what people are looking for, and then it's a question of whether this is sustainable or feasible even, is something that's more circular, that kind of collapses a lot of these open loop sort of resource in flows and out flows into something that is more managed internally to at a certain scale. And cities in particular want to do a lot of what's sometimes called a more circular economy. So I'll get to that in a moment. So one of the things I wanted to remember is this formulation of this slide, which was in my title. And this is actually from Dana Meadows. There's a little bit overlap between Pablo's talk and mine, which I was happy to see. I'll tell you more about her in a second, but she was one of the people of the club of Rome that authored this important study around that time of limits to growth. And in a later talk in the 80s, she died recently, she kind of formulated what the laws of sustainable systems should be. So the idea here is like, any law is like the laws of physics or something, is that these are things you cannot avoid, they're necessary, but they may not be sufficient. And if you would like, I always ask that probably there's at least one missing that I can think of. But the point is that the first law, every renewable resource must be used at or below the rate at which it can regenerate itself, was basically what Partha was showing us in terms of having basically acquiring a natural resource or something that is consumed by humans at a certain rate with a certain efficiency. So you basically cannot do it, and Pablo is asking, can I consume it below that replacement capacity and what happens? So this is saying this is a necessary law of sustainability. But that's just the first one, okay? The second one and the third one are more or less in the same spirit. They say every non-reduable resource must be used at or below the rate at which a renewable resource can be developed to substitute it. And then every pollution stream, so sort of the outputs must be met at or below the rate at which it can be absorbed or main harmless. So for example, with carbon dioxide and methane, we're not doing this, right? So we're just piling it up in the atmosphere with consequences for changing the climate, same thing for plastics and so on. Okay, so the point about these first three laws is that they're physical laws. They're basically a way of writing, if you will, if you want to be a physicist like we are here at ICTP, it's basically conservation of mass, conservation of energy of a certain kind, right? Where we take a little bit, the ecosystems into consideration, but we really didn't say much about ecosystems, right? We just are saying that there's some production of renewable resources out there by something. The fourth law, so these are, according to Dana Meadows, she attributes them to Herman Daley. And he was an important sort of person that was writing around this time. He was one of the founders of a subfield of economics called Ecological Economics, which is a subfield that's not really mainstream in economics, at least not in Chicago or AM, but it's very interesting and deals with some of the things I'll be telling you about today. And the fourth one is really about, so it says something, I'm just gonna read it. Capital stocks and resource flows, so it starts very physical, must be equitable, distributed and sufficient to generate a good life of every person. And she says, it's really a quote, not equally, but fair, okay? So this is kind of about people. And it seems like a nice thing to say, right? We should say this. It's about equity. If you look at any sustainable plan, it has equity at center now, but it's not very clear why it's necessarily to me, it wasn't. So this is often credited, she credited this to Carl Henrik Robert. He's kind of famous in Sweden, he's a Swedish doctor who wrote basically a pamphlet about what sustainability should be in the late 80s, early 90s, and the king of Sweden liked it. And so every kid in Swedish schools learns about the natural step, which is what that was called. And this is partly why Sweden is so tuned into, sustainable development has played such an important role, so education matters. But bear in mind these four laws, and this is kind of to me a good way of kind of summarizing a lot of things and coming back to them. As expressed, as you can see, they're just verbal. But here's sort of the picture that goes with them, okay? So without the people, just for the first three. So a motto, though you could print on a t-shirt, maybe you could do it for this workshop, is to another SFI here, or at least SFI associate, Harold Morowitz. Great researcher died recently of particularly early life and the origins of life and other biotic processes. And so it says basically, matter cycles, energy flows, okay? So this is a way of saying, second law thermodynamics is essentially energy flows, it's transformed, it goes into heat eventually, but matter cycles, it means that at least for the earth system we can think of matter as being conserved, right? So it doesn't escape, but so it needs to cycle. So there's a system, we're gonna put things in that box in a moment, but for now, energy needs to be obtained from the outside, from the sun eventually, but sometimes by the wind and other places, of course, also fuels. And then materials come in as well and they get transformed into other material, sometimes the same material, and they go out. And the point about this is that when they go out, usually they're dealt with to a large extent by nature. So we often call this euphemistically ecological services, but this is one way in which methane is recycled, or CO2 is recycled by plants to some extent, and other things get broken down. So part of the point is to create a system that does this with sort of the formulations that we were describing, and that basically closed the loop of the circulation of materials and obtains energy in ways that are nondestructive. So that's kind of the first three principles encapsulated in a picture. And so the point is that now you can play this game, if you think that this is a fundamental picture, you can play this game by putting things in the box, there are different. So you can put a person, you can put yourself or your household, and think, can I actually bend all these resource flows and close them within my household? And the question is gonna be no, right? There are many things you need to get from the outside, from the inside. Maybe you can produce part of your own energy if you have big house and solar panels and so on. So there are things you can do, but there are things you cannot do, okay? So that's a building or institution. I'm sure your university, I think University of Trieste is thinking about this. To what extent can we do that? Recycle within home, generate energy. What about a business, right? We've heard a little bit from Mealy Coffee and others, right? All businesses are saying they're gonna do some of this, right? What about a city? So I'll tell you a lot about later. Almost every large city on the planet is saying that they're trying to do this. I'll show you a little bit more specifically how, and of course, the nation or the world. So what's the right scale to close these loops? Right? At the moment, we're not closing them often, but so this is part of the question. It's a question of practice to some extent, but it's a question also that's tied to often the physical nature and the energy needed and so on of closing these gaps. So in some sense, part of this idea of localizing sustainable development is that you can think of the world from the point of view of these first three laws of sustainability about energy and materials in terms of a decomposition into all the households in the world. If everyone was sustainable, the worth would be sustainable, all the cities and settlements big and small or all nations, of course, this is what we'd be trying to do with sustainable development goals and the UN system is to declare that every nation is gonna try to be sustainable and by doing that, we got a world that's sustainable or even some geographic decomposition of the kind that we do, for example, in climate models by having tiles or something. But the point is that there are other things that cut across these, like businesses or governments that are not actually the sum of governments is not the world, the sum of businesses is not the world, there are other things besides the businesses and so they help and they cross cutting. But basically, there's this very important question of practice, which is who's responsible for circling these materials, recovering them and so on and who has the agency to do them, at what scale is that bending of the cycle appropriate or feasible and a lot of what happens, of course, for example, is that businesses try to push the responsibility to consumers, to you and obviously, you cannot do some of those things, because you live in a system. So part of the tug of war here is who's gonna take responsibility and who should take responsibility and how far is the scope of the responsibility at some scale. So I'm gonna come back to this and just give you some examples about how some of these could work quantitatively in terms of just simple models, they're not gonna be exhausted, they're just illustrations. Okay, so this is the first one, the first law of sustainability and it's more or less what Sir Partha was showing you, it's kind of hidden in a different way and so what I wrote there was, so you see the boxes, if you like boxes, the whole point now is that we have these feedbacks. We have a renewable resource R and we have a consumer CE, which is the system and the consumer is taking in the resource, it's creating a feedback in terms of reducing the population, typically of the numbers or some quantity of the renewable resource and the renewable resource is renewable so it has a certain rate of recovery. So I wrote those two equations, it's a canonical form, what are those equations? Who can tell me who those equations are? Ladaker Volterra. Ladaker Volterra, okay. So Volterra, right? Yay, we're in Italy. Okay, very good. So if you are sort of a mathematical ecologist, this is kind of like one of the first things you learn, you learn to analyze this, you know the system has oscillations, right? It's not very good control in terms of producing these very oscillatory systems and it was developed as you know independently by Ladaker and Volterra. The story of Volterra is that he did it having in mind fisheries in the Adriatic, so wait for the next slide. There'll be a surprise, maybe for some of you a surprise, but the point is that you can start asking questions about when are these equations stable and therefore you can consume the resource and have it get renew itself and when not. So for example, you can ask if consumption rate beta is larger than alpha over C, it's almost what Separtha was telling you, it's just kind of a little bit different, but it's almost the same equation, the same condition. Then you know the system crashes because you're consuming too much relative to the rate of replacement. And so this is, it's very easy to over consume when the population gets large because you can see that the parameter just needs to be greater than zero and it's a parameter greater than zero, so the zone at which you save goes down and down and down. Okay, so the alpha is almost the same parameter, you have to put the alpha down if C is going up. And coexistence possible, but it requires a bunch of considerations. So this was done mostly for fisheries and for other predator pre-systems, but I thought I'd look into it because why not, right? So this morning actually, forgive me, I was looking a little bit at where this come from and where did Volterra get the idea exactly? So you may know the story, but if not, this is a great story for your mathematical biology efforts because the story is that there was this man, Umberto Dancona, who, so Vida Volterra, of course, is a mathematician, very famous already, very lustious man already, but a problem came to him that Umberto Dancona, this guy who was an ecologist, was intrigued by the fluctuations of fish landings in Trieste, right? How good is that? So I didn't know that anyway. And so, but of course, every great story has several ingredients, right? So every great story has fish, right? I'm Portuguese, so I had to say that. But no, but every great story has love, right? So why did Umberto Dancona come to Vida Volterra and so on in state and they worked together is because Luisa. So Luisa Volterra, you see there in the photo, they marry there already. So on the right there, there's Luisa and Umberto and their daughter at the stage, Silvia, and you get everyone else. So I think this is a great story. So it's the beginning in some sense of how we understand sustainable systems and it all began with the fish of Trieste and the love story. Okay, so you can now go to the other laws of sustainability and elaborate them, right? And I'm just gonna show you that this gets very baroque, but it can be done if you want to pursue this path. You can start, continue to have these very abstract models. They don't have space, they don't have population structure or anything. But you can build boxes now where you can say that you're gonna have a renewable resource that starts replacing the green one, starts replacing the non-renewable resource. You can write equations for this. This is kind of like you can do it if you know these models, it's just pretty simple. And this has a certain structure that you can solve for. Okay, so typically what these models would do is that if you don't replace the non-renewable resource you have that the system grows and then crashes when it runs out of resource. But if you do the substitution fast enough, there's a regime in which you can go on as long as then you obey the first law of sustainability and then you continue to harvest at a rate that is consistent, okay? And this is like the third law about pollution stream. You add another box that is related to another set of equations and these aquas just typically have equilibria and zones of stability that work well, they make the system sustainable and other zones where the system is unsustainable. So you can pursue this kind of thing. The whole point here are the feedback loops. It's all about the feedback loops. So those are clear and present and it's on those time scales that the system is essentially sustainable or unsustainable. So the point is that you cannot just think open loop, you have to think in terms of feedback loops. And a lot of the exercises I do in my students always, particularly people that come from social sciences that write me the causal diagram, write me the thing with the boxes so that I can see every time that I can follow arrows that close on themselves, then I have a feedback loop that's either positive or negative that creates good things or bad things. Okay, so this way of thinking is very old and basically is very old from the 1970s and 80s. And in some sense originator, so this is a very famous book, Jay Forrester. This is the MIT way of thinking of complexity, if you will. And it's really about, this became system dynamics, the first application, it's just a happy coincidence for cities. And you can see a model there in the same spirit about different quantities. I'm not gonna spend a lot of time explaining, but it has to do essentially of what makes a good city in terms of some aspects of their economies and businesses and migration. Okay, and the point is again the same that some of these feedback loops generate dynamics, feedback loops always generate typically exponential dynamics that can run away from you, but if you have the right sort of feedback loops that stabilize the system in some parameter regimes, the system will go on and produce good things, but you have to know where you are in parameter space. And so this is the part that's the same as Pablo's. This became then applied to a world model called, this became essentially the limits to growth model, that was a book. And again, this slide is a little bit busy, but the idea is that the researchers that were trying to do this was trying to build a model of resource consumption for non-renewable resources. And so the idea is that as population grows and takes up the non-renewable resource, at some point it looks like everything's going well, it will continue to increase, and at some point it will start collapsing, okay? So this, of course, this is kind of, I didn't show you the more complicated one that Pablo had, but here's a version of it, right? The idea at this point was not that was because of climate, that was because of carbon and environmental degradation or biodiversity loss, it was about non-renewable resources and populations, they were too big, right? So what we have today is a bit different, but nevertheless it's the idea that these feedback loops will come and get you, okay? And if you're interested in this, you know, through the wonders of the internet, these codes have been ported into Python, there are documents online explaining how they work and you can run your own model of the world and so on and you can play the parameters and save the world or doom the world or whatever you need to do. So, okay, so, and this been redone, it's always in the press, but basically, it seems to show that, as I said, for the wrong reasons, but it seems that in some sense we're not out of the loop in terms of solving this problem, but so far what I showed you is the old way of thinking. It's not to say that this is not important, but is in some sense very unspecific, right? We're talking about non-renewable resources anywhere or the whole biosphere or something, but what we've learned so far in the last, you know, whatever, 40 years, is really that there's a structure to these complex systems, both ecosystems and human systems, and these structures kind of mediate some of these parameters that you see on the whole and put a lot of structure into them and this is the kind of knowledge that you need to have if you're gonna start addressing the problem in a more feasible way in various locations in a way that adds up and so on. So, I want to spend the rest of my talk talking a little bit more about that. So, first before I do that, I'm just gonna show you a couple things that's scary, okay, that just show you like we don't know what's going on. So, this is a common index of biodiversity loss. It's a living planet index. This is from our world in data, which has lots of wonderful data that you can download and so on. This is mostly an account of vertebrates and it monitors certain populations throughout the world. Sort of the people interested in biodiversity and conservation will know about this data set, has many problems, but from Latin America, like Pablo is or other people here of Brazil, it looks pretty bad and it's kind of hard to know exactly why. It turns out it's mostly because there's a lot of land conversion into pasture and that's being lost. That's a little bit the story of the rainforest, but other places in the world look not so bad. So, when you look at land uses, this is again a big aggregate worldwide, but this came up this morning. This is kind of interesting. If you haven't looked at this, it's more or less obvious once you look at it, but you know, so based on some of the arguments that Pablo was telling you about somebody like E.O. Wilson has proposed that we should leave half the land mass alone to be wild. So, this is the idea of half earth that we should keep half the earth at least natural. So, I think this came up also in Partha's arguments towards the end in one of the Pablo's questions. So, when you do sort of just the mapping of land, which we're now doing very well with satellites, you get more or less what I'm showing you here. So, you can look sort of the latest few dates, which are at the bottom, and the point is that we're using about half the surface of the earth for various uses that are human driven. You know, what's the biggest problem? You can read it, I'm not gonna ask you in stop, but it's basically grazing. It's land used for cattle. So, if you think that, you know, if you want to address the first problem first, that would be the first one, then there's a lot of land also used in agriculture, and then cities, urbanization that people, the places where people actually live is actually less than 2%, it varies depending on how you count exactly if you count empty spaces about between one and 2%. So, cities occupy a very small part of actually the land surface, and most of what we're doing in terms of habitat loss for species, which is the main way in which with satellite data we're actually addressing, trying to estimate biodiversity loss, is really due to land uses, the primary ones being grazing and crops. Okay, so this is kind of interesting because it starts suggesting, at least in principle, that if we can kind of do what I showed you before, that put everyone in these cities and kind of close the system more such that these cities are not destroying land, you could do a lot of good, right? And you can certainly create a lot of connected ecosystems that can support larger diversity. Okay, this is another one. If you think about why did emissions really go up so fast and so scarily in the last 20 years, it's partly because a lot of countries that didn't develop before are now developing, as you can see from this plot, the main thing is China. China really, it's a country that quickly became, had very fast economic growth, but also became the manufacturing central for the world and so you see that. So what should we be worried? So you see at the same point that the USA or the European Union, even before that, at least according to this data, have been actually reducing their emissions for a while now, which is kind of good news. But as long as India and Africa, which is still not reached the development levels of China or other countries, are gonna take a trajectory like China as then we doomed, right? So this is part of the problem and this is a good place to discuss that, ICTP, because it's an international place, but this is the problem that in some sense, the places and the people that were the least guilty of creating the emissions are the ones that have to somehow solve it in a different way, because if they don't, we're all screwed, right? So this is part of the problem and so what I want to say now, sort of in the last little while, is that how much time do I have? Until 50, okay, good. Okay, so one of the aspects that we observe in ecosystems, of course, but we also observe in human systems, is that they're organized spatially, but also functionally, in terms of a certain kind of hierarchy of both energy and information, right? So the familiar one sort of on the right here, for me, on the right for you, is the ecosystems live on this energy flow, right? The energy flow comes mostly from the sun and then goes to primary producers, which is staying the rest of life, right? We were discussing this morning and this then flows through a few other levels of predation and consumption and then it gets dissipated away, right? And this also recycles material. So some ecosystems are more closed than others. Ecosystems like rainforests are very good at closing a lot of material flows, but ecosystems like rivers, for example, don't. They live on the flow and that's true also of some ocean currents and so on, so there are different kinds of ecosystems in terms of material circulation, but this hierarchy is very important and human intervention sometimes is to destroy habitat, which destroys everything. Sometimes it's predation like fisheries on some elements along the chain that have different consequences for selection and so on. So this is kind of important to know how you're messing with these systems or what are the consequences for that structure and viability. But in human societies, we also have a structure where basically early on and the kind of thing that Pablo is describing, a lot of human settlements are more or less interdependent with their immediate interlens, the region around them for food and water, but increasingly as we have more and more cities in the world urbanized, you now have something that has very large cities with the global footprint and with very complicated flows. So what happens is that these top levels, both the large city and sort of the consumer, actually exert controls back into the system. So this is well known in some parts also of conservation that often if you don't have predation on the herbivore, you have depletion of the primary producer and the whole system kind of is impoverished. When you have more predation, you actually can have, for example, forest that sustain not just grassland and the whole system is more balanced. So there are a bunch of things that happen like this, they're interesting, and as my point next is gonna be that large cities in particular exert a controlling effect on the entire environment because they're essentially the orchestrators and the facilitators and sometimes the exploiters of resources worldwide. And so by acting on the top, you can actually change, it's one good place to change the structure of the entire flow of systems, okay? Yes. Information or energy, which, so energy is going, being dissipated up. So what I meant to say is that energy is harvested usually in small villages and agricultural communities and flows up and it's consumed in larger cities, the energy poor and so on. So the amount of, and there's dissipation along the way and there's information control that basically is flowing down and there's innovation from the top to learn the bottom to make it do so that energy gets there, okay? This is a simplistic way of saying, but it's very important and actually concerned. So a lot of the changing the systems is that adaptation in the energy that parts of the system have on other parts of the system such that the system continues to work and particularly as it gets more complex and these change get longer, that becomes more and more important. So this is the informational part and in some sense this informational part is the news. We kind of have known that populations and energy flows this way, but the part about information, whether it is relative to economic growth or whether it is in terms of evolution is really kind of crucial, it's not very available to us and in some sense ultimately, this is what biodiversity is, is information in nature about other parts of nature and the environment. Okay, so urbanization is going on and there were these two dates, so I'm gonna go a little faster now, but basically it looks like this. When we look at the hierarchy in space, this is India of course, it looks like, you know, you've seen these photos at night, they're very sort of charismatic, but you see these large cities are very bright and then a bunch of other cities. This has a structure that's been sort of exploited a long time ago, this structure is not exactly true, but it's known as central place theory, but the idea is that larger cities have larger territories. They actually provide services, but also get materials and so on from larger parts of the world and their landscapes. And they exert controlling influences and become markets and become centers of innovation, centers of political organization for larger territories. So when you see an urban hierarchy, you see basically that this is this kind of functional hierarchy of resources flowing up the hierarchy and information flowing down such that the whole system works. Okay, when you look at this in terms of an energy hierarchy, on sort of, this is a little complicated, but I'm showing you something about power density, so the amount of energy used per unit time, per unit space. Okay, this is typical of the system. So the power density of cities is quite high. This is for nation states, this is a kind of data set that Singapore and Hong Kong are sort of the exemplar cities, but you see they have much larger population density and much larger energy consumption per person, so this is power density. And this is kind of an ecological concept that the Odum brothers developed a long time ago that still needs to be better quantified, but that in some sense what happens in these systems is that the acceleration of energy use, but also of money circulation and exchange increases as you go towards these centers and it's lower sort of in smaller places. So there's sort of a way in which these systems are organized and controlled, and the whole point is that a lot of sort of the problem of sustainability needs to be addressed using some of these properties, and the point I'm gonna make sort of in just the last few minutes is that to go to the centers of control is a good idea, and these centers of control, which are the large cities, are actually places that at an intuitive level they know that they're doing this. They don't know it with science, you know, they're trying, maybe we're the kind of people telling them that, but in some sense they know they're at the center of these flows. They know they have the innovation and the financial power to change them. They don't always have the full political power to change them. So when you look at these places, I'm gonna, Pablo did a little bit that will work for me, so I'm not gonna show you this. What you have is disproportionate energy use and economic production and so forth with population size, which reflects this more connected but more information rich networks that larger cities are relative to smaller places and so on. So, but this is kind of from the when, it's just showing you that even though the world at this point on the slide was made, it was only about 50% urbanized or so, so a few years ago that all these good things and bad things were disproportionately centered in these places. Okay, so these environments also create a lot of kind of contradictions, which is a concept I'm not gonna explore too much, but part of the problem is always that when you have development is this or you have a sustainability solution, can you actually address these three problems at once? So these three problems are in some sense a reformulation of those four laws of sustainability, where equity being the fourth becomes important. Okay, so what I'm about to tell you now, this is a quote from Martin Novak, sort of theoretical ecologist of a sort. He's very interested in problems of collective action and group selection and the quote, as you can see, he's telling you a little bit about how is it that we create collective solutions in societies, both in biology, but more importantly now in human society. And ecology and evolution have an answer for this, that I don't see reflected in the literature in the social sciences. Surely this is the most important problem in the social sciences, right? It's about social action, right? Social knowledge and social action. But ecology and evolution has its own answer that is sort of latent and it's kind of still not very well developed. So these are examples I explore a lot in my book, which is here, but there's this interesting book by David Sloan Wilson about how evolutionary theory and group dynamics actually evolves in a lot of community dynamics and policy, particular from the bottom up, that actually guide a lot of successful solutions. So if you're interested, these are good sources and this book is interesting. So I'm gonna go through this a little quickly, but the idea is to go to an environment of population dynamics in selection. So the idea is that populations, so what people do, where they are and so on, but this could also be about biological types, evolve given some factors that control essentially the growth, the differential growth of different types. And this is basically what we call fitness, but in the social context, we often don't call fitness. This structures the system in different ways. So fitness is a measure of information. I could show you this with information theory, but I'm not going to. But so biodiversity is also information. But the idea is that some types are amplified when they're desirable and they're doing well and some are de-amplified and may become extinct. And the idea is that this concept of fitness, written as I just wrote, which is the standard way, is decomposable across levels. So you can think about an individual belonging to a family and then belonging to a city, for example, and having basically cost benefits that have to do with their affiliation to each one of these levels, there are different, and that the individual compounds into a global cost benefit analysis. The idea is that joining larger groups is the only way to really create large benefits, but also is subject to exploitation. So this is at the basis of problems of altruism and so on. It's more general and it's part of group dynamics, but it means that humans live in this nesting of identities and affiliations that they need to manage and this is often managed by politics and other means, but this kind of becomes a lot of a conflict. So the idea is that usually one goes to this, the price accumulation, if you're interested, I could develop this slowly in a different talk, I'm not gonna do it, but the price accumulation tells you when something can be amplified by this selective dynamics and how it can be amplified differently at different stages of these group affiliations. Some dynamics, for example, for sustainability has to be a group dynamics. Some dynamics of cost benefit will happen in terms of the effort they put in that's individual. And so you can unpack these equations at different levels and create essentially a way in which the calculation has group dynamics, individual dynamics, and you can ask whether the group dynamics is worth it, whether you gotta benefit from it or not in terms of the cost that you have to pay to belong to that, in terms of the kind of suppression of freedoms that you have. So there's a beautiful set of resonant ideas that go with that. I'm a big fan of Marty's Sense, so he has a book I just finished reading, so I put it here, which is called Identity and Violence and Speaks Precisely. It's written after September 11th. It's about Muslim identity mostly, but it's really the idea that good things only happen when we are able to exercise, use and exercise collective dynamics. So the idea is that any problem of collective dynamics has these ingredients. You need to create higher collective payoff, so it has to be worth it to solve the problem of sustainability. It takes information, it takes fair redistribution of the benefits. So you said until 50, so I have two minutes. Maybe we have time for just a couple of questions. I'm just gonna show you a few things. So cities are kind of playing this role already, so just let me just show you this and then this. So this is the mayor of London. He just says, you know, nations move aside. Cities are measuring a lot of their carbon footprints. There's a certain way they're doing this, which is internal, but not their full influence. And you can see basically cities starting to decouple their carbon emissions from their population and economic growth, such as you see here. But this now comes on the background of standardized data that's being produced worldwide, now by hundreds of cities that are doing essentially the same thing because they associate it with themselves. So this is kind of a picture. It's a picture full of interesting things. You see that Milan and Venice are here. They have relatively small footprints, but there are places like Lagos, Nigeria there that are probably underrepresented in terms of their future energy use, which is still very small per capita. So all these ideas are basically coming from a lot of applications in cities. They are now following that trajectories for wastes and carbon emissions and so on, and try to follow sort of this trajectory of sustainable development goals. So I'll just finish by showing that this kind of wealth is creating and solves a lot of the economic and social problems that we see in societies. And at the same time, we're seeing now a big reversal because with COVID, we've had a big reversal of these processes in which people are able to collaborate and work together and be educated and be healthy and so on. So it's really a time of great uncertainty as we go forward, as we can see also the war in Ukraine and the problem of energy being reversed relative to some of the progress that was achieved. So I'll just close with this quote. It's by a designer I like a lot and who's been to SFI, he's in Chicago, so I just had a pleasure in reconnecting with him. He did some of the graphics for our institute, but he's really an interesting mind. And so you can read the quote, but in some sense, the most important thing is, you can also put that on a t-shirt. There's no exterior to our ecology in terms of externalities. In some sense, when we look at the problem of sustainability, we need to think ecologically across scales, but also find the ways for people and nature to have agency to solve the problem and for it to be worth it. And that may well be the most complicated thing we do. Cities are natural at being able to do some of that, but nevertheless, we're kind of missing sort of a kind of institution, level of agency and structure of fairness and clarity of signals that allows us to do that. So thank you. Thank you very much. So that was really a lot of...