THE SUSTAINABLE CITY

Andras Bela Olah*

*Corvinus University, Villanyi Str. 35-43 1118, Budapest, Hungary, Email: [email protected]

ABSTRACT: Environmental consciousness and the expectable demographical and urban trends make two totally opposite sets of claims on the city. These can only be satisfied at the same time in a holistic way, by applying new technical solutions based on new urban planning methods and directives. The basic idea of this imaginary “ideal city” is that buildings are constructed of new materials and built with new kinds of engineering tools, which enable them to function in a carbon-neutral way; furthermore the traffic system includes pedestrians alone, while the necessary speed of transport is provided by moving sidewalks. The street network is 3-dimensional, where the vertical “streets” are formed by the elevators of the buildings, and the moving sidewalk network consists of several levels. With a new kind of transport system this district outlined above will become the industrial, commercial and economical centre of the entire city; furthermore they will become particles of a global city network, the City Planet.

KEYWORDS: ideas for and ideals of sustainable cities, urban transformation

1. THE PROBLEMS OF PRESENT-DAY CITIES

The problems of present-day cities are very complex. Cities as concentrated forms of human communities have an enormous impact on their environment, both on a local and a global scale. At the same time such serious problems have arised from this high concentration, which cardinally question the livability of certain cities. There is another problem arising in the cities, which is not a result of the urban lifestyle itself, but of a global phenomenon, which comes into prominence especially in these densely populated areas. In one word this problem is sustainability. Since the beginning of the industrial revolution the human race has got hold of such energy and raw material sources, which have opened up extraordinary perspectives. Consequently a radical (exponential) population explosion occurred, which resulted in the multiplication of the population of the Earth compared to the population at the beginning of the industrial revolution. The present-day issues arise from the finite nature of these raw material and energy sources; furthermore their usage causes enormous environmental problems. The reason why all these appear especially in greater cities is related to the fact that the industrial activities increasing in rate are located mostly in these cities; furthermore the great mass of overpopulation appearing as a result of the population explosion are almost exclusively concentrated in these cities too (it can be observed on every continent that those people who cannot find their livelihood in the rural zones automatically move to the urban zones, even though usually subsistence is not secured there either). The problems arising from the high concentration and density are the following ones. The built-up density and the rate of artificial surfaces are extremely high on the territories of the cities, which lead to the significant worsening of the local climate and indirectly to the increasing of the urban energy consumption. The energy-efficiency of the city buildings built according to the widely used building technologies of nowadays is very poor (buildings are responsible for more than 40% of the energy consumption of the world). The worsening of the urban climate increases the waste of energy further. The increasing of artificial surfaces eventuates the decreasing of natural territories (covered by vegetation). This results in the significant impairing of the urban ecosystem, the additional degradation of the urban climate conditions and the worsening of the general human living conditions. Indirectly, the lack of natural environment leads to the impairing of general mental and health conditions of the population on a long term (i.e. civilisation-illnesses appear). The extremely high population density and the fast technological development have been the cause of the multitudinous appearance of high buildings and skyscrapers. These buildings have much higher specific energy requirements than smaller buildings with only a couple storeys; furthermore they eventuate the increasing of the concentration, which typically leads to further infrastructural and transportation problems. The next group of problems is probably the most obvious one, and these are the difficulties arising from transportation. Traffic congestions are typical without exception in all major cities, and these cannot be solved in practice by any current urban planning method. Approx. a hundred years ago motorized vehicles were meant to relay horse-drawn vehicles and in that time they were considered as a very clean way of transport. As the cities and the number of inhabitants radically grew (along with the number of cars per capita), motorized vehicles have gradually made urban transport almost impossible; furthermore the usage of public spaces has been severely limited (by urban highways, transport areas, parking zones). A further problem is that the air pollution produced by this huge amount of motorized vehicles is so great that not only does it make urban living impossible in certain periods (e.g. smog alert periods), but it also causes global problems (air pollution, carbon-dioxide emission, other green house gas emissions, global warming). Public transport and alternative transport solutions (e.g. bicycle, electric car) are only able to solve single issues of the above group of problems, which consequently are only provisional solutions. The elements of the global sustainability problems in the cities are the following ones. The increased number of population appears in different forms in the environment of the cities. The European and North- American cities have developed a vastly extended residential zone (agglomeration) around the actual city. These agglomerations are usually ordered with a relatively high rate of vegetation, but they put a great infrastructural and transportation burden on the city. Usually another kind of residential zone evolves around other great cities (especially those in the tropical and sub-tropical climate zones), but these cannot be considered as ordered districts. These are the so called “shanty towns”. Their common features are the lack of orderliness, significant energy waste, a significant or total lack of infrastructure and extreme environmental pollution. Both types of urban extensions can be very damaging and they can lead to the dramatic fall of living standards in the inner parts of the city, or even in the entire city. Among the global problems appearing in the cities the sudden population explosion is the most significant, however, the extremely high rate of industrial zones also cause significant problems, by further worsening the living conditions in the city; moreover they increase the negative effects of the city on its environment to a very high extent. In short it can be said that without exception all cities more or less feature the predominant part of the global problems and several other local problems as well. A holistic mentality is necessary in order to solve these problems; hence inventing and using new kinds of urban planning methods based on the traditional technologies or using new technologies in existing urban structures will not provide true solutions.

2. THE TRENDS OF URBAN DEVELOPMENT, REQUIREMENTS OF FUTURE URBAN SOCIETIES AND THE LOADABILITY OF THE ENVIRONMENT IN THE FUTURE

The trends can now be forecasted as below. The global population will grow further; Planned Parenthood is unable to stop this growing, nor can it decelerate its pace; all it can do is influence the pace of its acceleration. The other existing trend, which most probably will not change in the future either, is that the major and continuously increasing part of the population on Earth will continue to dwell in cities and urban zones. These two phenomena together will result further population explosions and significant territorial extensions in the cities. The complexity and the built-up density of the cities shall also increase. These trends already exist today; however, the scale of these trends is expected to radically accelerate in the following decades. However, the negative effects cities have on their environment already exceed the natural regeneration capability of the planet to balance these effects. The scale of these negative effects highly depends on the actual size of the cities (besides the given technological level). Considering the above, the potency of these effects is also bound to suddenly grow at a high pace. It is also problematic that the structure of the cities will inevitably change after reaching a certain size. This “critical” size depends on several circumstances; e.g. the cultural factor is highly significant. Thus when considering the number of the inhabitants, the “critical” number is the smallest in the North-American cities and it is the largest in the Eastern-Asian cities. By now the number of the inhabitants in the largest cities has exceeded 20 millions and the diameter of their borders has reached a hundred kilometres. By these sizes such districts have already emerged by necessity, which cannot be considered liveable at all (the city is unable to provide basic human rights in such areas). Several types of such districts can be distinguished. One of these is the downtown area featuring extremely high buildings eventuating high built-up density (the metropolis centres of present days). The other district type usually located peripherally in the urban structure is the so-called “shanty town”, which (literally) only provides shelter for the residents. In the first case it is the extremely high stress and the lack of pedestrian and green public areas, which turns the district into an unliveable environment (it provides merely workplaces), while in the second case the problem lies in the fact that the fundamental living standards (infrastructure, public security) are not provided. In certain special cases there are further district types to be found as well. Certain cities (especially in the post-soviet countries and in countries industrialized early) extended “brown fields” (formal industrial, functionless areas) can be found, while coastal cities typically have harbours and harbour districts. Both types of districts significantly impact their environment. In a social respect the transformation of “brown fields” into “shanty towns” may become a serious problem on a long term. In the case of the harbours the increasing number of inhabitants and the corresponding increase of economical and industrial needs inevitably result in the extension of the harbour districts and this eventuates a much greater negative impact on the environment. On the whole urban development on the entire Earth can be prognosticated for the next few decades as the following: the number of city inhabitants is bound to grow explosively. The territory of the cities will considerably extend and among the urban districts the proportion of the unliveable ones will radically grow. Probably these unliveable districts will form the greater part of the cities. The industrial zones are expected to extend along with the infrastructure and the public utilities; however, the overall rate of the public utilities will decrease. These all lead to the radical growth of the negative environmental impacts. Transportation is also bound to increase according to the growth of the population and the city size (involvingly); however at the same time its efficiency might even decrease radically (regular, huge traffic congestions extending over several districts). Locally the rate of the pollution will reach such a high level that it will directly react upon the living standards of the city, primarily through the air quality, the rising of the temperature and the increasing number of extremely hot days (urban heat island). The pollution of the water bodies around the cities and furthermore the lack of clean drinking water can also be expected. Globally the combined effect of all the increasing loads will lead to the acceleration of the negative global processes (climate change, desertification), which on the long term suggest the opportunity of a sudden and radical end to this kind of urban development.

3. FUTURE REQUIREMENTS FOR THE CITIES

As it can be seen from the above, there will be a great need in the future to create an absolutely new type of cities, which will be capable of providing human rights and appropriate living standards for their inhabitants, and furthermore which would also be sustainable (after 200 years again). Thus it is a main requirement that the city provides in a sustainable way residency, workplaces, public areas, green surfaces for its inhabitants. It is also a basic requirement to have a totally built urban infrastructure, which is available to everyone and functions appropriately. The requirements of transportation are similar with proper functioning as high priority. The long term aspects also have to be taken into consideration, hence the transportation and the infrastructure system cannot function on a basis of temporary solutions, but they have to work immaculately for a long time. It is very important for cities to be as compact as possible, for the huge urban distances (over 100 km) are great problems for urban transport; furthermore long daily travels (several hours per day) significantly decrease the living standards of the inhabitants. All of these requirements can be met by implementing the building, architectural, technical, planning tools already in practice, except for the case of transport. However, these tools can not in the least be considered sustainable, environmentally conscious or ecological; hence they absolutely contradict the sustainability requirements of the cities. Cities should not have any negative effects on their environment. This is strictly demanded by the expectable radical growth of the population; hence those building, architectural and urban design tools which are forward-looking but do not result radical improvement should be used. If any environmental load is accepted even to a low extent, then due to the radical growth the same rate of the negative impacts will reappear after a very short time period. This rate is already unaffordable both in the cases of big cities and even smaller towns. That is why the positive minor developments are not enough on their own. According to this the cities of the future must be absolutely carbon-neutral, and in addition no other kinds of pollution (waste-, water-, soil- and air-pollution) are affordable either. In order to achieve carbon- neutrality it is necessary to decrease in many orders of magnitude the energy consumption of both the buildings and the infrastructure, furthermore to eliminate the air pollution on the spot caused by the transportation system. At the same time this significantly reduced energy requirement must be supplied by sustainable energy sources, thus achieving carbon-neutrality. In the case of the waste materials the present industrial processes (which are based on non-sustainable energy and raw material sources) have to be revised and re-established; this enables the use of such raw materials and energy types1 which so far have been of no account (not because of technical issues but out of convenience). The greatest urban energy consumer is the urban transport system and additionally the buildings. The solving of all these problems is primary. Possible solutions for these will be presented in the followings.

4. THE URBAN TRANSPORT SYSTEM

The most important problem, which must be solved even in the existing, traditional cities, is urban transport. It is not only the greatest urban energy consumer, but the greatest urban polluter as well, and its effects appear directly in the degradation of the urban living quality (smog). Another, though less significant, but still important aspect of this situation is the way transport systems have developed in the urban public spaces during the second half of the 20th century; these designs extrude the citizens out of the major part of the public spaces and thus set a very strong limit to the possibilities of utilizing urban public spaces. In the present days urban transport basically consists of motorized vehicles. These are either private or public vehicles and they operate with either electric or oil/gas engines. It is clear that the greatest problem is caused by private oil/gas engine vehicles. However, considering the expectable trends of urban development, the problems cannot be solved by simply increasing the rate of public transport and electric engine vehicles, perhaps only just for a short time and not even in every city (in cities over 20 million inhabitants the above is not a solution). It is very important to note that the motorized vehicle is a multi-functional tool; consequently it is unable to attend with high efficiency to such a specialized function as urban transport. It is possible to undertake both transcontinental travels and daily short trips within a settlement by car and by train as well. The denser the city, the lower the efficiency of the motorized vehicles. The critical rate of density depends on several circumstances. In the case of urban highways with multi-level urban nodes the efficiency of car traffic can be relatively good, however, in this case the limited usability of the public spaces becomes a major issue, furthermore in cities with a population over approx. a hundred thousand the efficiency starts to show a decreasing trend (e.g. due to traffic congestions). The usage of bicycles and other alternative urban transporting tools is a true alternative; however, their usage is strongly limited primarily by urban weather conditions (especially in countries with colder climates). On the other hand they have to face the same problems (although on a different level) as motorized vehicles, e.g. bicycle congestions or parking conflicts and difficulties; thus their widespread usage is strongly limited. The aim is to combine the advantages of pedestrian traffic with the high speed of motorized vehicles. The usage of high-speed moving sidewalks is a possible solution for this. In such densely populated areas as the downtowns of great cities, especially when considering the directions of their expectable development, it will be impossible to continue transporting citizens with an increased number of individual vehicles after reaching a certain critical level of traffic intensity; instead the streets themselves will have to carry the inhabitants. The moving sidewalk has to meet three basic requirements to become widely used in urban transport. First of all it must be weather-proof which enables it to be used in open spaces. This can be easily achieved by using an appropriate structure. On the one hand a watercourse must be integrated in between the moving and the motionless surface elements and the edges of the pavement must be formed with a drip; on the other hand the neighbouring moving pavement elements should connect to each other forming imbrications. This

1 Olah, A. B., "Turning Disadvantages into Advantages" IFoU 2011 Conference Publicaton, In Press, 2011. way the engineering device itself can be placed into a totally weather-proof space (beneath the moving pavement). The next requirement is the necessary high speed. This can be solved by using several parallel moving sidewalk bands. The speed difference between the neighbouring bands is small (only 2 km/h); still the innermost and fastest band can be almost arbitrarily fast (it is limited only by the width of the entire system and the wind). The third requirement is the safety of the beginning and the end point of the moving sidewalk. This can be ensured by designing the moving pavement bands as a circulating system (i.e. the bands turn back at the end of the route, providing the possibility to proceed at high speed in the opposite direction). To enable this, the moving sidewalk elements must be designed with a special crescent shape [Fig. 1.].

Figure 1. The structural scheme of the crescent-shaped element of the moving sidewalk system

This solution can also be used in the already existing urban fabric. In the case of wider roads two squares are required at the beginning and at the end points (usually these exist). The square must be 72.4 metres wide and the road must be 37.4 metres wide in the case of a maximum speed of 22 km/h). These squares are necessary to provide space for turning around the moving sidewalk (the turning procedure needs great radius in order to keep the centrifugal force low). In the case of narrow streets the “one way road” concept can be utilized as a solution, which means that the parallel narrow streets can be used to travel in the opposite direction. The minimal width of the street in this case is 21.2 metres, but the width of the moving system itself is only 13.4 metres. Consequently this solution even can be used in existing cities and settlements [Fig. 2.]

Figure 2. The scheme of the moving walkway system by the case of an existing city structure

The urban nodes of these moving sidewalks are multi-levelled (as the greater urban nodes presently are). In the case of building new cities the possibility is available to design perfect circle shaped circuits, which enables the usage of a radically simplified moving sidewalk structure. Due to the wind it is not practical to build moving pavements with a maximum speed higher than 20-25 km/h. However, the innermost, fastest travelling band can be equipped with benches and windshields (which on the other hand would significantly increase the energy consumption). Nevertheless a maximum speed of 20-25 km/h enables the designing of urban districts with a diameter of approx. 20 kilometres (approx. 300 square kilometres). In such an urban district every point can be reached from the centre under half an hour. The actual inner parts of the cities fall into this category in Europe (Paris: 100 square kilometres; Budapest: 525 square kilometres). The advantages of this moving pavement solution is its incredible flexibility (no need for bus stops or for seeking parking), its maximal efficiency: there are no traffic congestions and the efficacy of the system can be finely tuned to the number and the weight of the travellers; there is no acceleration and deceleration, there is no more air pollution and 100% of the urban public surfaces become pedestrian spaces. Cities with a diameter larger than 20 km usually consist of several (formerly independent settlements), thus they have many districts and many centres. For this reason it is practical to design separate moving pavement systems for each of the centres and districts, while the transportation between these centres should be solved by a fast and high capacity public transport tool. Logically the railway seems to the most suitable solution, since it is the most effective vehicle on such medium range distances. The railway has one disadvantage in respect of energy efficiency, which, however, can be easily solved in cities, especially in the case of existing metro lines. The operating of the railway demands relatively much energy due to the air-drag and the regular acceleration and deceleration, even though the rate of the rolling resistance is extremely low, actually almost negligable. However, if the train ran in a tube (as it usually does in the case of the metro) and the air was pumped out of the tube, then the air-drag would also be negligible, furthermore if the electric engines worked as electric dynamos when braking (electric engine brake), the energy consumption of the railway could be reduced by many orders of magnitude (!). Obviously the inner space of the trains must be hermetically isolated and pressurized, and the boarding and getting off may only happen through hermetically closing “elevator” doors (airlocks). By combining the two transport systems introduced above, any city, regardless of its size, can be provided with an ideal urban transport system, which features all the advantages of the existing urban transport systems and certain new advantages as well (e.g. public spaces turning into purely pedestrian spaces), while the functional and ecological disadvantages become eliminated.

5. THE BUILDINGS OF THE CITY

Under the present circumstances buildings are responsible for more than 40% of the global energy consumption. This means that radically reducing the energy consumption of urban buildings is indispensable in case the aim is to develop carbon-neutral cities. The energy consumption of the buildings consists of two main components. The first is the energy demand of climatizating the inner spaces and the second is the energy required for the inner transport of people and materials. The climatization of the inner spaces, especially due to the huge energy sources of the last two centuries, has not been as significant as before (e.g. in the vernacular architecture). Due to the inexpensiveness of energy and the continuous technical development climatization has been solved by designing engineering tools (heating, air-conditioning) instead of increasing the thermal isolating abilities of the building structures. The reduction of energy consumption even up to several orders of magnitude is essential for a carbon-neutral city. However, it is impossible to return to the building structures used before the industrial revolution, for the living circumstances which have radically changed in the meantime have made such demands (several hundred metres tall buildings, transparency), which cannot be (widely) provided by traditional methods and structures under urban circumstances. There is a material which has never been taken into consideration as a building material before; still it can serve as a solution, as its physical qualities make it absolutely suitable for being used as an ideal building material. This material is water, especially the salty water, brine. It is absolutely transparent, an excellent heat isolator; it has extremely great specific heat and a relatively low specific weight (most of the building materials used widely are heavier than water with at least approx. 250%); furthermore an extremely low thermal expansion coefficient too, and all these advantages deserve more attention. By producing a suitably high concentration of salt (brine) the freezing problems can be totally solved, while the specific weight only grows in a very small rate (less than 10%). Obviously as brine is a liquid, such a structural material becomes necessary, which is solid and covers the brine body. Taking the static and transparency requirements into consideration, the combination of glass and fibre-glass would be an ideal solution2, which is able to meet all existing demands, and in respect of conditioning it has incredible advantages. The effects of the daily temperature fluctuation can be totally eliminated by using adequate facade structures in the inner spaces, and depending on the local climate conditions the energy demand related to the seasonal and yearly temperature changes can be reduced by many orders of magnitude by using the adequate corresponding technologies, e.g. heat exchangers (passive house quality). This way (and in some other ways too) the heating and cooling energy demand of the buildings can be reduced by many orders of magnitude, furthermore when considering the necessary materials and their producing processes an absolutely new, sustainable industry can be generated.3 The other significant problem is the energy demand of the engineering tools in the buildings. As it was mentioned earlier, in the present days the climatization of the buildings is basically provided by building engineering tools (heating, air-conditioning), thus replacing them with adequate building structures would significantly reduce the total energy consumption of the buildings. The other very important factor, which appears especially in the case of high houses and skyscrapers, is the energy demand necessary for transporting people and materials inside the buildings. As in the case of these high buildings the water reservoirs of the city are on a lower level than the upper storeys, the water carriage to the upper levels must be individually solved in the buildings (with interior pumping systems). The transport of other materials and people is carried out by elevators. As the potential energy is proportional with the mass and the height, it is obvious why the specific energy demand is so high in the case of skyscrapers. Fortunately there is a possibility of reducing this kind of energy consumption by many orders of magnitude. This possibility lies in the potential attribute of the gravity field, i.e. the same quantity of energy, which is necessary to transport a given object to a certain height, can be gained back by transporting it back down (apart from a minor unavoidable loss). In practice this means that as much drinking water has to be transported upwards, so much wastewater has to be transported downwards too; furthermore as many people are transported upwards will be transported down too, and the same situation occurs with materials as well. Thus the only task of the building engineering tools is to gain back the potential energy of the people and materials travelling downwards. In the case of elevators this means that the elevators are not decelerated by brakes, but by a dynamo (transforming kinetic energy into electric energy), which can be solved relatively simply by applying a minor conversion to the engine device of even already existing elevators. The conversion of water carrying systems is not as simple, for in the case of pumping the turbulence in the flow leads to a significant dissipation and energy loss. Consequently the entire system itself must be totally changed. The pipe system may remain unchanged separately on each storey as before, but between the storeys (in a vertical direction) the water must be carried in a discrete system (a sequence of water tanks, which carry the water onto the appropriate storeys). The major part of the energy demand of this system can be provided by the similarly designed wastewater system which transports the wastewater downwards, producing electric energy in the meantime.4 To sum it up, by following the methods described above the energy demand of the two greatest energy consuming systems in the buildings, the climatization and the interior material and person transporting system can be reduced by many orders of magnitude. The energy demand of other energy consumers (indoor and outdoor articles of personal usage) can also be reduced by appropriate tools and solutions (LED lamps, gravity lamps5 etc.). This incomparably reduced energy demand can be covered by

2 Olah, A. B., "The Ideal Building Material is Transparent, Light, is a Good Heat Isolator, Just Like…" IFoU 2011 Conference Publicaton, In Press, 2011. 3 Olah, A. B., "Turning Disadvantages into Advantages" IFoU 2011 Conference Publicaton, In Press, 2011. 4 Olah, A. B., " Radically Decreasing Energy Consumption of Buildings by Using the Potential Attribute of the Gravity Field" IFoU 2011 Conference Publicaton, In Press, 2011. 5 http://inhabitat.com/gravia-gravity-based-kinetic-energy-lamp/ sustainable energy sources, and their generating devices (solar cells, wind turbines) can even be located onto the building itself, not only enabling the possibility of creating a carbon-neutral city, but also of transforming the former buildings into carbon-neutral buildings. Obviously the necessary energy demand of the city cannot be totally produced on its own territory; however, the possibility to cover this entire energy demand (or even more) in an appropriate way6 from sustainable sources in the immediate environment will be available.

6. THE CONNECTION BETWEEN THE NEW CITY/DISTRICT AND THE FORMER, EXISTING TRADITIONAL DISTRICTS

These kinds of building and infrastructural/transport elements discussed above provide the possibility of building totally new cities/districts, which can be installed incredibly flexibly. The possibilities and advantages of these new districts are to be discussed in the followings. The buildings are high buildings, skyscrapers, which have been designed according to the structures and engineering methods introduced above. Since they are carbon-neutral, their height is limited only by static considerations. The connection between these buildings is provided by moving pavement systems. In case the buildings are very high, there is an opportunity of designing several street levels (one street level per every ten storeys), which provides maximal mobility and formulates a real 3-dimensional street network, and where the elevators of the buildings are the “vertical streets”. The average distance between the buildings must be bigger than in the present practise in order to enable the necessary amount of sunlight required for the lower storeys and for the relatively big amount of surfaces covered in vegetation. This multi-level, 3-dimensional street network enables the street level(s) to detach from the ground level. Creating multi-level nodes becomes logical; furthermore this solution resembling elevated railroads enables the designing of perfect circle shaped circuits (in the air) in the case of newly built districts, which significantly simplify the structure of the moving pavement systems. [Fig. 3.].

Figure 3. The scheme of a newly established city

The connection between such new districts and the already existing traditional districts can be achieved by connecting the lower street level of the new district with the street network of the older districts using the moving pavement systems. This provides an organic and undisturbed connection and a maximal integrity of functions between the old and the new districts even in spite of the obvious differences in the urban morphology.

6 Olah, A. B., "Turning Disadvantages into Advantages" IFoU 2011 Conference Publicaton, In Press, 2011.

7. THE CONNECTION BETWEEN THE CITY AND THE REGION

There is an absolutely new possibility of locating these new kinds of districts in the case of coastal cities, due to the fact that the street level can be separated from the ground level. This possibility is the erection of the new district into the shallow sea, on the shallow bed, where the buildings would be constructed similarly to oil rigs and would serve as huge bridge-piers for the streets resembling the layout of bridges. This kind of localization has many advantages. First, there would be a new direction in which the cities can extend, sparing the vegetation of the mainlands from being covered. Furthermore in the case of coastal cities, these new districts, which’s primary functions are commercial, industrial and economical, will automatically gain an excellent urban structure connection with the harbours and economical areas. The usage of the railway system (running in vacuum tubes) mentioned earlier means a further opportunity as well, as it can easily be used on the sea7 (obviously even without the highly expensive MAGLEV system). Thus due to its location on the sea, such a district can even become the centre of a new kind of sustainable industry8 (featuring solar and wind turbine farms).

8. THE CITY AS THE NEW DISTRICT OF THE EXISTING CITIES AND AS THE DISTRICT OF THE CITY PLANET

The vacuum tube train has another incredible advantage, which will eventuate an unbelievable change in human society. Since in the case of this new railway there is no air-drag and the rolling resistance is neglectable, the maximum speed is unlimited (!). The fastest trains (rolling on wheels) presently reach the speed of 500-600 km/h, and the only reason for this speed limit is the air-drag. Considering the attributes of the vacuum tube, the train can reach a multiple times higher maximal speed than which the airliners are able to. Furthermore almost all the energy necessary for acceleration can be gained back during deceleration (by using the electric engines during deceleration as electric generators). This means that the energy demand of such high speed travelling is incomparably lower than that of an ordinary train travel. These two advantages (the extremely high speed and the extremely low energy cost) are such tools, with which it becomes possible to totally transform the global infrastructure, shifting freight transport from ships, road haulage and traditional trains to the new railway system along with passenger transport from airliners, traditional trains, buses and cars (exactly the way as the moving pavement system takes over the role of all the traditional urban transport tools). Considering all the above these new kinds of districts will not only take over the commercial and the economical functions of the traditional districts, but also the industrial functions; furthermore their residential function will also upvalue on the long term. This radical transformation of the artificial environment holds one further potential. Since the connection between these new kinds of districts will be provided by the vacuum tube train travelling at a speed multiple times higher than that of the airliners, these new districts will be accessible faster from their centres than the traditional parts of the city. Consequently these new areas will not only be new districts of the existing cities, but the they will become districts of one huge global city; an absolutely sustainable and carbon neutral city able to take over all the economical, commercial, industrial functions from the older parts of the cities without causing them or the vegetation any significant structural damage. This way the concept of the City Planet can be realised.

7 http://www.impactlab.net/2008/06/27/trans-atlantic-supersonic-maglev-vacuum-tube-train/ 8 Olah, A. B., "Turning Disadvantages into Advantages" IFoU 2011 Conference Publicaton, In Press, 2011. REFERENCES

[1] Olah, A. B., "Turning Disadvantages into Advantages" IFoU 2011 Conference Publicaton, In Press, 2011. [2] Olah, A. B., "The Ideal Building Material is Transparent, Light, is a Good Heat Isolator, Just Like…" IFoU 2011 Conference Publicaton, In Press, 2011. [3] Olah, A. B., " Radically Decreasing Energy Consumption of Buildings by Using the Potential Attribute of the Gravity Field" IFoU 2011 Conference Publicaton, In Press, 2011. [4] http://inhabitat.com/gravia-gravity-based-kinetic-energy-lamp/ [5] http://www.impactlab.net/2008/06/27/trans-atlantic-supersonic-maglev-vacuum-tube-train/