In our video today, we will discuss sustainable development. Surely this is a broad field, and we'll address only a few aspects of it, only those which will help us understand more globally urban issues, and the issues of planning, of course, for this is our key topic. In theory, there are three spheres: the economic sphere, the social sphere, and the environmental sphere. These three spheres are independent, the economy generally preceding the social or the environmental, for while the link between social and environment exists, it is much weaker than that between the economy and the environment. The basic pattern, these three spheres, autonomous, with links to one another. The diagram of sustainable development is one which utilizes these same three spheres, yet they overlap and ultimately it is at their intersections where we find the questions of sustainability. So in order to be sustainable, we must take into account economic, social and environmental questions, and their relation to one another, paying close attention that one does not take precedence over the other. When we discuss sustainable development, or sustainable urban development, there are two basic theories. The first says that sustainable development is impossible, that the term is an oxymoron, which is to say that the two terms have opposite meanings. Or there is a conflict between development and the environment. We cannot have, at the same time, economic development and environmental development, or rather one cannot preserve environmental resources, if one is developing the economy. This is the first theory, by those who begin with the questions of reduced or lowered energy consumption. The second theory says exactly the opposite. It says that sustainable development is possible, this mainly because of technology, and the efficiencies it provides, in other words we can use technology to increase yield, and in doing so, use less energy, or use it more efficiently. This is the second theory, by those who are positive about technology and sustainable development. As for these two theories, we won't choose one or the other, but will examine for ourselves a certain number of criteria which, we believe, will lead us towards a sustainable city, or in any case a sustainable urban development. First, though, if one considers the work of Newman and Kenworthy from 1999, they present the following hypothesis, which is not really one, for while they present and prove that this consumer curve exists, and that the annual fuel consumption, per person, is directly linked to, or has a direct relationship to urban density. The denser my city, the less fuel I will use, as seen in Asian cities. And the less dense the city, the greater the fuel utilized. This is the model of the American city. We see this here, American cities, and here, Asian cities, and between the two there we have the European city. Another example offered by Benoît Lefèvre, based on the work of the same authors, Newman and Kenworthy, those of Atlanta and Barcelona. Similar populations, urban areas which are calculated in kilometers in Barcelona, and hundreds or thousands of square kilometers in Atlanta, We see a very different consumption, which proves that the denser the city, with the same number of inhabitants, the less fuel consumption or, more globally, energy or CO2. It depends which indicator is used, but they are all linked to one another. So, what does sustainability mean to us? It's from this point of view where I would say that we are situated neither with the first theory which doesn't want sustainable development to exist, nor in the second, where we think that everything's fine, it is somewhere in between the two, since sustainability, when one speaks of urbanization, is still a reduction in energy consumption. We've just seen the curve, where density allows this reduction in energy consumption, particularly in the preservation of natural resources. This is the starting point for a system of governance which is sustainable, sustainable over time, while all rapid political change hinders long-term project planning. Its inverse, if the governance is sustainable, one can extend projects to medium or long terms. Financial impact, the same thing. If we imagine that urban sustainability leads to financial stability in the long term, and also has a long-term impact on public health, on life expectancy. We normally use economic indicators, but we can also use, as indicators of urban sustainability, the life expectancy of its inhabitants, and imagine that the more elevated life expectancy, the more sustainable the city. This remains to be proved, but can be an indicator among others. Finally, sustainability, at any rate urban sustainability, is we can call a peaceful society, or where numerous people live together with mutual understanding, without armed conflicts, guerrillas, gangs, or those groups who spread trouble and violence, like we've seen in recent events. So it is a peaceful society, which is to say that living together is commonly embraced by all. So to reduce energy consumption, because this is the crux of the war, without a doubt, it can be waged on construction, on the building. Let's take as an example those buildings with little insulation, where air conditioners are to the max, where energy is consumed. There exists, in bioclimatic architecture, and without making any value judgements, possibilities to reduce energy consumption, most notably the electricity consumed by air conditioners, via natural means, of air circulation, cooling methods, which have been known for a very, very long time. But let's say that addressing the issue of buildings is a starting point. In the North it's a question of heating, in the South it is generally around the question of air conditioners, because more often one looks to cool rooms, rather than heat them. We can also address mobility, for as we've just seen there is a direct dependence between fuel consumption, on the one hand, and density. So finally, in planning one can go further. And, finally, the third aspect relates to individual behavior. There are some forms of consumption which are causes of the urban model, or those due to the architecture buildings or the building methods used, But energy consumption depends, primarily and directly, on human behavior, on lifestyle. And it is on this last aspect where one have the most influence. There are many other areas were we might initiate changes to reduce energy consumption, but these are the main ones: human behavior, mobility and built environment. The symptomatic example of what one should not do, when it comes to energy consumption. We are in the city of Dubai, in the middle of summer. 45 degrees in the shade, outside. On an artificial slope, inside an enormous commercial center, we are skiing. As far as energy consumption, there is surely nothing worse than skiing in the middle of the desert. To finish up this very, very quick video on the two or three aspects of sustainable urban development. To summarize, or to conclude this video we could say that what we're looking for are planning methods which ensure long-term effect. We also are looking for decision-making structures which allow this long-term management. This is why we can take action at once on these questions of energy, on urban forms, housing, human behavior, mobility, but we must also influence those government structures which determine whether or not to implement these efforts to lower energy consumption. In our future videos on planning, we will keep this in mind. How can we, today, reduce our daily energy bill? Whether it is the cost of CO2, or a financial one, a monetary one, or of liters of fuel, or calories, whatever indicator we might use, but the key word is the reduction of this energy amount, per person, which one needs to live in a city.
