 So, welcome everyone, the topic for the afternoon is Sustainable Development, I am pretty sure that many of the teachers are already familiar with this topic, but I am going to share some ideas about sustainable development that maybe some of them you might be familiar with and some of them may be new to you. So, I will give a brief introduction about the basic concepts, but I expect that the teachers will have already done that or if they have not done it that they will do it on their own. So, this is the outline of the talk and this is this topic is going to span two sessions, so I will stop somewhere over here for a break and then we will continue in the second session. So, I would like to begin from the very basics where we when we study the topic on biogeochemical cycles, we look at the various segments of the environment and then we study all the biogeochemical cycles like the carbon cycle, the nitrogen cycle, the water cycle and things like that. These cycles give us a sense that all these segments the atmosphere, the lithosphere, the biosphere and the hydrosphere that they are interacting with each other. So, there are interactions within each segment and then there are interactions between segments and it is these interactions all put together which we call as the biosphere in the broader sense. The biosphere has a narrow sense in which it talks about only living organisms, but in the broader sense it includes all that supports life as well. So, the biosphere which has so much of diversity and there is a topic in this course called biodiversity. So, all that put together what does it mean to us? Many of us are probably engineers and we do not have a very good sense of what really that biodiversity and all these interactions actually mean to us or how do they benefit us. So, I think people who have already taught this course are very well aware that it is extremely important for us because all that we get all the ecosystem services that we get from nature including the fresh air, the water, the soil and the food and everything that we get from nature actually depends on these interactions. So, these interactions in some sense are working in a coordinated fashion to enable us to lead our lives. So, they are benefiting us. Now, although we generally understand this, we probably do not quite well connect how our actions in one area affect something in nature which apparently is very distant. So, in order to emphasize this point, I would like to show you this short video it is only a 5 minute video where you see how the reintroduction of one species of animals which is the wolf in the Yellowstone National Park led to profound changes not only in the biological community over there, but in fact even in the way the rivers ran. So, the rivers basically altered their courses, the whole topography had a great impact by the reintroduction of this species just a single species the wolf. So, the wolf was there in Yellowstone National Park before, but it got hunted down and then it was reintroduced. So, that reintroduction actually had a cascade of beneficial effects. So, let us see this through this very nice video. So, was in that a fantastic video? I mean it is in 5 minutes it communicates such a profound idea that the ecosystem is actually the ecosystem and the biosphere all together is actually working so hard to create these life friendly conditions for us and that is exactly what James Lovelock observed when he was an atmospheric scientist he worked with NASA and he actually tried to study the atmospheres of planets and through that to infer whether life existed on those planets or not. And he figured that in contrast with other planets the earth has an atmospheric chemistry which is very unusual and he according to his study he found that it was life that was creating these conditions which are very suitable for life. In other words the plants the green plants they absorbed carbon dioxide and they gave out oxygen that is why we have 20 percent oxygen in the atmosphere which is what leads to life as we know it today. So, looking merely at the atmosphere one infers that the earth must have life which is actually doing all this. So, he had a theory and he called it the Gaia theory which was inspired by the Greek earth goddess Gaia. In India we have a similar concept of the earth goddess our Bhuma Devi Bhudevi. So, the concept was that the earth with all its intricate and interacting systems behaves as if it were a super organism. So, it is not to say that the earth actually is a super organism but it does behave as if it were a super organism and so what are what is this behavior like a super organism that we are talking about it is the interaction between various parts to constitute a whole. So, the earth actually behaves as if it is a whole and it has self regulation it can if there is a disturbance it can correct the disturbance. For instance all of you are probably sitting in some seminar hall or some computer lab so which probably has fans or air conditioners. So, supposing I turn off the air conditioner what happens so your body heats up so when your body heats up. So, I am creating a disturbance I am creating a disturbance by allowing your body temperature to rise. So, how does your since you are an organism and not an inert object you can correct that situation the high temperature is not good for you and hence the body responds by sweating so it corrects this disturbance. So, the earth also due to the which is obvious in the chemistry of the oceans the atmospheric chemistry and so many other systems that we see in the earth that the earth is able to self regulate which is a characteristic similar to life. That is why he says that the earth appears as if it is a super organism. So, if we actually accept this theory it actually opens up a new perspective towards looking at nature. So, we start to see nature as something that is beneficial for us as something that supports us and without which we are nowhere. So, it can it can actually be the foundation of the conservation movement which it has in many ways. So, although the biosphere is so beautiful and nature supports us and nature supports life and nature is full of biodiversity what we find is that presently our world is plagued with a number of environmental problems and the list is very long I have mentioned a few over there they are like global warming ozone depletion deforestation desertification loss of biodiversity and so many more. So, all these really serious problems so serious that in fact some scientists believe that you know we could be heading for a near collapse of the biosphere. So, we are faced with so many problems while we have achieved great progress in technology. So, the technology and the progress and everything is good, but it has come at a very big cost. Now, how much exactly is our impact on nature how do we how do we estimate that of course we would like to have we would like to put numbers on it we would like to understand it in some quantitative way. So, the ecological footprint is an estimate or is an approach to try to estimate our impacts on the environment and the logic is thus that we many of our activities tend to harm nature or harm the environment, but the environment as I told you it can self-regulate it can regenerate or restore some of the damage that we do. So, how much area would one person or a family or a city or the entire world would require in order to restore the impacts that they have on the environment. So, it is the ecological footprint is the amount of biologically productive land and sea area needed to supply the resources that a human population consumes and to assimilate the associated waste and damage. So, it is as I said it is reported in area units or it can be reported in in terms of the in in multiples of the biological capacity of the earth. So, when you say that the ecological footprint of humanity is it turns out that presently it is more than one earth it means that we are consuming more than what the what the environment can regenerate. So, this shows how at present we are consuming resources much faster than they can be regenerated as a result we are our ecological footprint is 1.5 times the area of the earth. So, in other words we have exceeded the earth's regenerative capacity by 50 percent. And if the current trend of development continues unabated in by by 2050 we may need nearly three earths, but we know that that is not possible because we have only one earth. So, we need to take some steps to actually reduce our ecological footprint and go along this trajectory. So, that by 2050 we would actually be requiring only the resources of one earth. So, workshop coordinators meet that we had in April I had asked this question if we have only one earth how can we consume more than that. So, in other words if you if you have only 100 rupees how can you consume 150 rupees. So, the the answer to that actually is that we are we are consuming not only the renewable resources which are which are restored, but we are consuming even the non-renewable resources or we are consuming renewable resources beyond the renewable capacity. So, there is going to be a depletion there is there are reserves of resources, but we cannot consume all of that. So, an example would be let us say you have a mango tree you can only pluck the mangoes if you start plucking all the leaves then you are you are eating into tomorrow's productivity. So, that is the point. So, as a result we find that presently we have an ecological footprint that exceeds the area of the earth. Now, the funny thing and it it is more than a coincidence that while we are having this environmental problem the list of environmental problems that I showed you which all come together as an an increased ecological footprint we also simultaneously have a social crisis. So, we have on on various continents we have wars we have terrorism we within within our country and in many other countries we have tremendous corruption and so many other social problems we have poverty the basic needs of many people have not been met there are something like 800 million odd people who are starving. So, in this world with so much technology we can go to the moon we are thinking of colonizing Mars, but we have not succeeded in feeding everybody. At the individual level also we see that there are so many problems there are health problems there are other lifestyle related problems that are there. So, is it is it merely a coincidence that while we have so many environmental problems that we also have a number of social problems. So, is it likely that the the environmental crisis and the social crisis are related I will I will put that question to you we will try to answer it or we will try to touch upon some issues related to this possible connection towards the end of the presentation. But all in all development which actually aims for at the at the basic level which aims at the survival of the human race and at at higher levels it aims at prosperity of humanity has now actually is now at a point where it some people believe is even threatening our existence in the future. So, is this the kind of development that we want or do we need to take some corrective measures in fact if there were no need of taking any corrective measures we would probably not be having this course. So, the unsustainability that we see the unsustainability has two dimensions the environmental crisis as well as the social crisis and all this put together is is what I would be using as unsustainability the term unsustainability whenever I use it throughout my presentation I mean both the environmental and the social dimensions of it. So, this has been understood to be something called as the tragedy of the commons. So, this person an economist Garrett Hardin sometime in the 60s had this theory of the tragedy of the commons where he gave an example of a grassland which is a common it is an open access resource which belongs to the entire village and people can have their cows graze on that they do not have to pay any tax and it is not regulated in any manner. So, when the common resource is shared by individuals who are rational who are intelligent who understand economics and there is no regulation of any kind then it inevitably degenerates the resource because people put in more and more cows so that they can get more and more benefit out of it. So, each cow that you put in yields milk the milk is privately enjoyed the depletion of the resource which is the consumption of the grass is commonly shared by everybody. So, when the damage is commonly shared distributed and when the benefits are privately enjoyed each person is tempted to put more and more cows on the grassland and when such a thing happens the grassland ultimately gets destroyed. Now, there is a slight correction over here the word commons as used by Hardin is probably not the best term because the commons is now better understood to be regulated commons. So, commons are common resources which are regulated by the public by mutual agreement whereas the in the sense that Hardin used it is an open access resource. So, nevertheless many resources in nature today are open access and people are not controlling themselves which is leading to this tragic situation that tragedy is basically the degradation of that resource. So, we just understood the nature of the problem that we are facing and we obviously are not happy with that we do not want development to harm us we want development to yield prosperity to mankind. So, we need to solve this problem and how do we solve it? So, we need a new model of development which does not emphasize nearly on economic prosperity but it also balances the other two factors which are very important to us which is society and the environment. So, while we said that economic development is happening at the expense of society and at the expense of the environment we need to balance it and we should aim for economic development that needs the needs of the present while preserving the environment. So, that it does not hamper the the ability of future generations to meet their requirements. So, it is it is quite obvious that you cannot have too much of inequality in society that is that is not going to be stable it is it is not going to be in line with this paradigm of sustainable development and we cannot damage the environment we can we can use the renewable resources but the non-renewable resources by definition they cannot be renewed and therefore they are going to get exhausted there is going there are going to be impacts. So, if we if we understand this basic concept then we are we are in the game otherwise no matter what we do you know we cannot stop this problem of unsustainability. So, these three pillars society economy and environment they are called as the three interdependent and mutually reinforcing pillars of sustainable development interdependent because you cannot achieve one without the other two. How can you achieve economic prosperity if there is social injustice to an extreme extent then it will simply not last and for any economic process the environment is the ultimate resource you know. So, if the environment is degraded then you cannot get economic development. So, they are interdependent and they are mutually reinforcing because if you if you do it right you will you will be able to get all of them. So, if you are if you have the correct policies if you are if your economic development is on solid ground then it will naturally lead to social justice as well as environmental protection. So, it is ok to say that we need sustainability, but how do we actually bring about sustainability. So, I want you to pause a little over here and maybe in your notebook just write down may 4 or 5 points if you can write 10 that will be good. So, if you can write about 5 to 10 points on what you think should be done to bring about sustainability sustainable development. I think do we have do we have agreement on the need for sustainability I hope everybody is in agreement with that. So, if you are in agreement with that I want you to note down a few points as to what you would do if you are a policy maker what would you do in order to make that happen ok. So, what I had told you as an exercise was to list down a few things that you would you would want to be done in order to bring about sustainability. I think most of you might have done we did not actually get a chance to probe how many people have noted down and things like that. But I am normally when I teach in my class and I ask the students to do this very same exercise they come up with a long list and I have kind of put together that list which I usually see in my classes and that looks something like this. There are many more I have just represented a few over there. So, something like you know stop deforestation replace fossil fuels with renewable energy reduce recycle reuse how many are familiar with this with these 3 hours reduce recycle reuse in the context of waste management I think that is pretty common protect wildlife and habitats which was one of the questions that we got. So, all these things and then there are some other things which are on the social side of it something like remove poverty and hunger because unless you remove poverty people will be forced to turn towards deforestation and damaging the environment if everybody is well fed then nobody is going to go on damaging nature. So, so many things actually come up to our minds. So, all these are very good ideas there is these are all very well meaning approaches that many people take and there are there are whole organizations that are non-governmental organizations that are very committed individuals which are working in each of these areas. So, I am not saying that what they are doing is anything less. But I merely would like to submit that if we pursue all these activities no matter how good they are the outcome is not likely to be sustainability we are not likely to achieve sustainability no matter how good these ideas are and why do I say that reason I am saying that is will be obvious in the following discussion. So, I am going to say that the fragmented approach of pursuing each of these good activities in a disconnected fashion is inadequate it is not going to be sufficient for achieving sustainability and the reason I am going to tell you is that we the environment this is the egg model or I have kind of adapted it a little bit. So, the environment is the entire is the superset in which we all live and within that we have the yellow the yellow ellipse which is human society and within that we have various organizations various institutions like the government our cultural organizations and things like that the economy and these various problems that we saw the environmental problems and then the social problems that we all saw they overlap you know they overlap between the environment and society. There are some environmental aspects to the food crisis there are some social aspects to the food crisis, but I want you to pay attention to these arrows over here the arrows tell you that the food crisis is not only related to itself, but it is related to the water crisis it is related to the economy it is related to governmental policies. So, there are these interactions that are there in within nature see within the environment also we saw that there are interactions between various segments. So, within society within various organizations there are interactions. So, the problems that we face also interact with other problems and other institutions. So, it is because of this nature of interacting systems that we will not be able to solve the problem simply by pursuing these activities such as planting trees and all that we would not be able to achieve sustainability because of that. So, then the question is how do we actually achieve sustainability. So, the answering that question is a little difficult. So, let us take it step by step I would rather start off by trying to answer or trying to look at the ways by which it cannot be achieved. The first way it cannot be achieved is by green wash. So, green wash is a term where used to describe a company or an organization which through essentially dishonest advertising or marketing claim to be green claim to be sustainable they are not doing anything substantial to improve their to reduce their environmental impacts they will probably do something very insignificant and then claim to be a green company. So, an example would be maybe a petrochemical company let us say it applies a few efficiency measures or maybe install some pollution control equipment and announces itself to be an epitome of sustainable business. It is far from that, but this is how things happen they even change their logo to something green or something that will kind of connect with our ideas of what is sustainable. So, that is green wash and that is not likely to lead to sustainability neither will mere compliance with regulations the pollution control board and the various regulatory agencies have got certain norms, but merely by following them it is not in fact many of those regulations are far inadequate in terms of what we actually need for sustainability. So, merely meeting them is not going to achieve our goal. Even at a personal level you know there are many people who say that you know if everybody takes small steps you know we can achieve sustainability before we know it. That is again not true because if you take if each person takes one small step then humanity as a whole would have taken one small step you could not have taken more than that. So, it is not you know these small steps are something like keep your car engine well tuned so that it does not pollute that much or get your PUC certificate for your car or something like do not use Palatine shopping bags use cloth bags instead. So, these are small steps which each of us can do and I am not saying they should not be done they should be done there is value in that, but do not imagine or do not delude yourself into thinking that you know just by doing a bunch of these small superficial things that you have achieved sustainability. Now, again one thing is that the race the mad race you know for economic growth is not going to lead to sustainability either. Some people subscribe to this idea of you know remove poverty and then sustainability will follow. Yes poverty reduction should be done in any case, but it does not mean that simply by economic growth you are going to achieve sustainability because if we follow a consumerist kind of approach then the inequality in society probably cannot be addressed. So, the social problems are not going to vanish and by the time the all the poor people are well fed the rich people would have consumed so many resources that there we would be on the verge of collapse. Now again this recall that diagram where I showed you the interactions solving one problem at a time might be impossible. I will give you an example specifically the food crisis if you are trying to solve the food crisis independently of the over population problem or independently of the water problem then you will never succeed because for instance the about 87 percent of the water that we extract from all sources in India about 87 percent of it goes for agriculture. So the water and the food problem are so closely linked that you cannot imagine solving one without the other so also with population. Again there are there is no there is no comprehensive view there are different governmental agencies NGOs businesses industries each doing their good and honest bit, but unfortunately if there is no coordination between them again it is very difficult and in order to in order to understand this last point I am going to give you an example, but before before we go there I just like to pose a question which you can note down and keep thinking about it as I as I go through I will discuss it again towards the end. The question I am trying to raise over here is that is it possible that unsustainability is a systemic problem since it affects all activities in the context of food in the context of the economy in the context of wildlife conservation everywhere it encompasses everything. So is it possible that it is a systemic activity and what I actually mean by that is that is it possible that all these problems that we see are mere symptoms of a deeper cause. So is it likely that these all the the environmental and social problems that we see are mere symptoms of a much deeper call it a root cause if you want. So I want you to ponder over it I will be going ahead with my slides, but I want you to note this point and keep thinking about it as I as I go further ok. So the last point that I had said which will not lead to sustainability was the fragmented approach where governmental agencies and NGOs and all of them do their own thing. In order to understand that this is an example if you have several musicians with different musical instruments and they are all experts at what they do and they all come and sit in one room and just simply do their thing you are not likely to create an orchestra no matter how experienced and how great experts all of them are and the reason is that there is no coordination between them the coordination is not likely to happen spontaneously. So unless they are planned together they agree to play one composition let us say and there is somebody some conductor who leads the group who tells when the violinist should start playing and when the tabla person is going to start playing and all that it is not easy to spontaneously have an orchestra. So something like this may also be true in the case of sustainable development and how far are we on that path is there is there an adequate consensus or understanding about sustainable development because now we have to take it to the context of different countries and within countries different states different political parties different ideologies. So I do not think as of now there is an adequate consensus again I leave it to your own opinions but I do not think there is adequate consensus most people I think would agree in principle that we need sustainable development and that sustainable development is good and that it is positive and we should work towards it but how much we should work towards it and in what way we should work towards it I do not think there is that much of a consensus. But nevertheless there are there are some interesting developments or there is some understanding that is evolving which I am going to some of those points I am going to share with you and hopefully you will you will appreciate them. So again there are I do not intend to cover each each and every slide there are I have more slides than I will actually cover in detail because I want to leave the content with you I want you to read it through at your leisure and maybe add some points on your own when you teach your classes so I am not going to cover all of each and every slides. So let us look at some of the developments in our understanding about sustainability and how to achieve it. So the first point is that sustainability must be designed coming back to that orchestra example you would you would agree with me that we need to design sustainability there must be a deliberate design both at a component level as well as at the process level and I am going to explain this a little more later. So this brings us to the discussion of need the need for systems thinking. So when you have these interconnected problems you have you have these interconnected systems you must get a an overall view which will allow you to understand the whole problem and then solve it. So the systems thinking basically a good way to state what systems thinking is is that the whole is more than the sum of individual parts. So an example is all the parts of a car do not make the car nearly. So if I give you a truck load of all the parts of your car four wheels and steering wheel and seats and all these things in random order I cannot you will not agree that I have delivered a car at your home. So you want all those parts to be assembled in the proper order only then does it gain its function. So it is the function that you are interested in and that is not possible merely by those components put in any random order. So these various aspects that are there about the unsustainability all those problems that we saw we must put them all in perspective and then only we can solve the problem. So I have a very nice video over here. So this video will explain to you what happens when you try to solve a problem without this understanding that we are basically the biosphere is the entire system in which we are but small parts. So when we do not have that understanding how trying to solve one problem actually ends up creating some other problems. So we are going to watch this video where there is a it is about it is the it is named cats in Borneo. So how they how in order to solve one problem the more problems were created my students find it very interesting. In fact this video was suggested to be to me by one of my students. So using the concepts of systems thinking that we just saw in that video if we need to actually apply these two to solve the unsustainability problem, let us look at it in the context of resource management. This is another video which I strongly recommend the name of the video is the story of stuff. This is a website and they have many other videos also very interesting but it takes about 21 minutes. So I am not going to show it to you right now you can watch it on your own. So this is a screenshot from that video where basically what you see on the left hand side is the resources of the earth and on the right hand side you see waste you know air pollution and solid waste and everything. So what we are doing essentially is we are running a linear system whereby we are depleting resources which are on the left hand side and accumulating waste and so we have the industrial production we have distribution and retailers and then we have the consumer which is our homes and then we have waste. So what they have shown here is an incinerator. So we are running a linear system and it is obvious that if we are running a linear system like this that resource depletion and waste accumulation on either side is going to lead to an ultimate collapse. So what actually we need for sustainability is a different paradigm. We need a cyclic or what is called as a closed loop system also known as we need to close the loop. So somehow or the other we need to extract resources from the earth but only the renewable resources and cycle them through our industrial and distribution processes, consume it and release waste which are easily compatible with the biosphere. If there are any items that are not easily compatible with the biosphere from our waste streams coming from our homes or point of consumption they should be cycled back to our production processes, things like lead for instance you know you use batteries, you use car batteries and the car batteries have lead. So things like that should not be released to the environment but should be taken back and put back into our industrial production systems. So if we follow a scheme like this then it is possible to achieve a sustainable management of our resources. So another example that I am giving over here because it is always easy for us to imagine smaller systems and our home is probably the easiest to imagine. Again similar to the previous slide I have the resources which are the inputs to our house on the left hand side and the outputs which are the waste streams on the right hand side. So in the middle is our house. So our house actually acts like a machine or a device that takes in nice beautiful clean resources from nature and in a linear fashion converts them into all sorts of wastes which end up cluttering up our streets, the solid waste, solid mixed waste polluting our waters and spreading diseases. So such a linear use of resources is obviously not sustainable and we need to change that. I have there is a lot more detail into this and I am not going to explain each and every detail you can see the diagrams on your own in your spare time but I am just giving you an overall idea. So what we really need is to kind of close the loop. So how do we close the loop some of the waste streams should be cycled back and converted into resources. So how do we make that happen? There are various ways you are already familiar with many of them. For instance the liquid effluent can be taken through a biogas plant it will yield some cooking gas. So it reduces your input of cooking fuel for the kitchen. You can also size it properly so that you do not need any other cooking fuel other than the biogas and then some of the food waste from the kitchen can probably go to a cow. The cow will return the some of the waste as an input for the biogas plant. You can have an organic garden where some scraps and other things can be put into the garden and you can get organic produce. So what you see is if you actually take conscious efforts to cycle the loop to close the loop you will find that it becomes much more sustainable than before. So the only probably unavoidable use of fuel is for transportation where if you again are conscious and use more of public transportation then your ecological footprint is much smaller. Some unavoidable consumer products may still be required but let us say the water source can be made green by having some rooftop rainwater harvesting and recharge of ground water things like that. So there are many things that can be done I have represented a few ideas only as examples it does not mean that there are no other ideas or no better ideas in fact there could be many better ideas. So now I showed you this for a small system can we manage resources in a similar fashion for a larger system? Yes it has been done that is called as industrial symbiosis where one company's waste becomes another company's treasure. So the waste stream of one industry or one process can become the input or the resource for another process. So there is a video we will watch only a part of it and I will cut it halfway through because we have limited time but it is an interesting video. I just wanted to introduce you to the concept there is more detail to it it is a kind of a systematic field of study and maybe it cannot be covered in such a short time but I just wanted to give you a flavor for it and how important it is. So this is again the Kalunberg industrial symbiosis that they described in the video. Again I am going to skip the life cycle analysis for want of time. So one of the points that I think came up in that video was that we need to design for the environment I mean what is the point in first designing a product without taking into consideration the environment and then worry about how it is going to what its ultimate fate is going to be you know whether it has to be incinerated or it is going to emit lead or mercury vapors and things like that. So it is always better to incorporate these ideas in the design process so that you can design things so that they can be reused or refurbished disassembly a planned disassembly can also be designed into the product. So such steps are very important in so in other words the company or the manufacturer they cannot only focus on making the product and selling maximum amount of units they have to be concerned about what is the entire life cycle and how they can minimize its impact on the environment. So this requires some out of the box thinking for many of us and such in fact in various areas you can come up with very innovative solutions if we have this kind of a perspective in our mind. I am just going to give you another example of a system which is I think very familiar to most of us this is about what we do with our organic waste. So commonly what happens in many places is that the food waste along with garden waste or leaf cuttings and things like that it is all mixed together and put in the municipal dumpster and along with the organic waste comes a whole lot of other waste which is not organic. So everything goes in the municipal dumpster and then it gets dumped in a landfill and many of the landfills are not even well designed sanitary landfills but they are just simply dumped on some open land and then somebody some well meaning person probably lights it on fire and then the whole place is like heavily polluted. So this is what commonly happens. So all of us agree that is not the best thing to do. So we think that this is something better. So we can think of a simple sustainable system where the organic waste is separated from the other waste streams and is put in the in a composter and you get some compost and what you do with the compost it is good for agriculture. So you can produce some food out of it. So you are not only getting or solving the solid waste problem partly but you are also kind of reducing the food problem. So you are making some new food. So that is good and you are I mean instead of a liability now you have assets, you have foods, you have food production so that is good. But what I want to propose is that that is not the best you can do. If you apply your mind you can do something even better. So only the system gets a little complicated. So just follow me with this. Let us say the food waste is collected before it rots. So let us say vegetable peels and you know leftovers from fruits and things like that. They are pretty, they are some at least part of it is cattle edible. If that is fed to a cow, the cow is a bioreactor which within roughly 18 hours or so will convert that waste into milk. So you got milk out of that and it also provides urine which has great agricultural value. Many of you might have heard these concoctions like Panchagavya and things like that which have very good results for agriculture. And of course it yields dung and the dung can go into a biogas plant. To the biogas plant you can add the food waste that is not cattle edible. You can also add garden waste to it and you can get biogas out of it. Now not only do you get energy the biogas but you also get a waste slurry and that slurry can again go for agriculture. So you are not essentially the agriculture in the previous system you directly added all the organic waste to make compost. So you are not taking a major hit because some of the slurry is still, I agree that a lot of carbon actually goes in the methane but some of it is, some of the organic carbon is still there in the slurry. So you can potentially if designed properly particularly if the cow urine is made into a very good bio fertilizer liquid fertilizer then you can get very high food yields. So compared to the previous system not only did you get milk but you got food and you also got some energy and then obviously you can let your imagination run wild and maybe put in a pyrolyzer if energy is of greater importance then you can take part of the garden waste and put it in a pyrolyzer. And a biochar that comes from a pyrolyzer is actually a good agricultural, it is a soil amendment, it basically it has a lot of, it is a high surface area carbon so microbes can breed in it and it can boost agricultural productivity. So I agree that it becomes, this is just a hypothetical example of how one commonly known system can be improved and refined by including more and more components. It does not mean that I mean each one would have to be scientifically evaluated whether it actually works and what is the benefit but this is just an instructive kind of example. So this compares these three where in the first case the food waste was land filled leading to a net loss, contamination of ground water, breeding of vectors and all that. In the second example you got profits by selling the compost or doing some agriculture with the compost. In the third case you can get greater profits because you not only get food but you also get other output such as the biogas and things like that. So if we actually want to design such systems to manage our resources particularly the organic resources you have to identify some organisms which may be plants or animals that consume our waste streams the organic waste streams and who themselves are robust and require minimal care and they yield something of high value. So if we strike a partnership with nature then nature has got such wonderful organisms which can actually help us convert some a process which is leading to a loss into something which can make great profits for us. Now it is time for the break. I just want to play the devil's advocate once again and say that this is not the whole story. We saw how resource we can through integrated resource management or rather sustainability requires integrated resource management but that I am saying that it is not the whole story because many other green technologies and many other things are going to be required and not only technology there are other areas in which similar development complementary development has to happen in the same direction. Just as an example I want to say that even the best technology will not succeed if governmental policies are adverse or if it does not make good business. So these things also have to be factored. I want you to in the break I want you to just think about maybe a list of what you think would be a sufficient set of conditions necessary and sufficient set of conditions for sustainability. So I want you to do that exercise in the break.