The sustainable development paradigm defined in the Brundtland Report (1987) should be regarded chiefly as a framework for discussion in which only the general principles have been clearly articulated. This framework opens up a wide range of public debate not only about its implementation, but also about the blueprints for action that might follow from its underlying values. So it contains an essential procedural component that is indissociable from the inherent aim of enabling all stakeholders, on every scale, to address the global issue of development and make it their own.
Two sides of environmental awareness
Ever since the Brundtland Report, the three “pillars” of sustainable development (economic growth, social cohesion and environmental protection) have come to be seen not as conflicting, but as mutually compatible objectives. What is more, the unifying concept is that of development, whose pertinence, however, is contested by a significant current of intellectual and political thought that has its source in the Meadows Report to the Club of Rome (1972). The definition of sustainable development in the Brundtland Report (I.3 §§ 27-30) unequivocally refutes the conclusions of the Meadows Report. Indeed, the Brundtland Report clearly hypothesizes not only that it is possible to reconcile the various declared objectives, but that in fact the achievement of each shores up the others. Conversely, the Meadows Report argues that, whatever choices and approaches contemporary societies may take, environmental disaster can only be averted by severely limiting – and, if possible, reducing – population growth and industrial production. So environmental concern must not be confused with sustainable development. It is important to distinguish between the two because, given the current configuration of the world of ideas, three different overarching conceptions of nature are at stake in the public debate, two of which lay claim to environmental awareness.
Those conceptions are summed up in the table below, which shows that the current debate is easier to grasp if we distinguish between three options – which, of course, are often presented in a muddled or inconsistent manner. We have tried to simplify as far as possible here by pushing each paradigm to its logical conclusion – at the risk, as always in such cases, of glossing over nuances and intermediate standpoints that do merit scrutiny. However, each of the conceptions in question exhibits a great deal of coherence, as reflected in the table: the agro-industrial, neo-naturalist and post-materialist models possess substantial resources for reflection not only on nature and development, but also on political and moral philosophy, various aspects of the social sphere (production system, social relations, space, time) and values, which, in all three cases, do seem to form a coherent system. This classification can help us understand how the urban relates to the debate over the role of nature in the future of society.
- Fig. 1: Nature and models of society in the current public debate
In the middle column, the city is among the expressions that can be criticized a priori because it is a manifestation of undue interference with (“impact” on) nature. This conception goes hand in hand with such measuring tools as the “ecological footprint” proposed by Mathis Wackernagel (http://www.footprintnetwork.org), the object of which is to point up the disparity between the surface area occupied by a community and the surface area of natural resources needed to maintain that community. The denser a city is, the greater – i.e. the more worrying – its “ecological footprint” will be. This tool is challenged by those who argue that the right comparison, all things being equal, should be between a scattered, spread-out spatial configuration and a compact one, and that the consumption of surface area per inhabitant decreases in inverse proportion to the degree of urbanization, a fact masked by the very way in which the footprint is calculated.
This criticism is aired particularly by those who point out that the city is not only a consumer, but also a producer of resources, and that opting for urban life allows one to strike an effective balance between the two and achieve a sound economy of means in its productive system as a whole, especially as regards natural resources. In accordance with this point of view, the right-hand column of the table suggests that the city does indeed figure in the sustainable development paradigm, and is actually a central element thereof. It might even be claimed that, by dint of its inherently modest consumption of land area, the city is the most economical spatial configuration in terms of soil sealing, energy consumption and greenhouse gas production – and all the more so the denser and more diverse its use of internal space. In this regard, the city, provided it accepts itself as such, can be deemed the spatial component of sustainable development.
Urban models and sustainable development
Nonetheless, the discussion of the sustainable city needs to be reinserted into a more general public debate about urban models, a debate that resumed in the 1980s based on a critical analysis of the impact of the modern urban planning movement and on the construction, based on new foundations, of the concept of urbanity. The environmental question has been tied into the question of urbanity in the context of new areas of conflict. Indeed, had the urbanization trend been so powerful and unequivocal as to admit of no possible inflexion, the debate about urban development would have been purely academic. This question is worth asking because in the eyes of many observers not so long ago, the model exemplified by Los Angeles (marked waning of the historical city Centre, splitting-up of responsibilities, sociological fragmentation, unrestricted residential sprawl, overwhelming predominance of automobile metrics) seemed to embody the future for cities over the world.
But that model, which remained in vogue till the late 1990s, has lost steam due to noticeable developments on the ground. The situation has changed in the wake of seismic shifts in urban planning in North America (including Los Angeles) replete with an inner city renaissance and all the concomitants thereof in terms of how the city is perceived. The same goes for newly urbanized areas in Asia where, despite the orientational confusion, the maintenance of high densities makes urban sprawl unlikely in those regions. And Europe exhibits a contrary trend (reinforcement of highly or moderately dense areas, continuation of suburbanization), in which the majority stakeholders – those who still desire an urban world based on individual housing and the automobile, with all the consequences that entails – are increasingly delegitimized.
So the debate is wide open, though rendered more complex by a host of conflicting studies that sometimes make it hard to draw any clear-cut conclusions. Moreover, a close analysis of urban situations in terms of sustainable development tends to militate against fetishizing specific technical objects or types of architecture as being good or bad in and of themselves. It should be remembered, for example, that dense networks of individual family houses and large high-rise housing estates have similar residential densities.
- Fig.2: Two basic conflicting urban models
If, to simplify, we distinguish between two basic models, one centered on the integrated city (“compact city”, “Amsterdam model”) and the other based on urban sprawl (“Johannesburg model”), it turns out the prevalence of these models varies according to location and scale, as shown in the following table. That means that public policy cannot be the same for the Centre of a European metropolis such as London or Paris and for the outskirts of a small city in North America – or in Europe, for that matter.
- Fig.3: Geography of the prevalence of urban planning models
That being said, it does not seem impossible to make out a few key nodal points where the contemporary urban dynamic and the prospects for the sustainable city intersect.
Mobility: the crucial issue
Mobility remains a crucial consideration that sums up the issues of sustainable development pretty well. In fact, this issue can be taken as a yardstick by which to gauge the extent to which various concrete objectives satisfy the demands of the various pillars of sustainable development. For example, one could envisage achieving the first objective by developing “clean” cars that do not emit greenhouse gases. Assuming all the existing cars were to be replaced by non-polluting vehicles that are produced at affordable prices and rapidly enough to anticipate the depletion of fossil fuels, it would also be necessary to reduce land surface coverage and soil sealing to protect the soil, biodiversity and the water cycle. That would mean limiting road, rail and waterways networks and increasing the building density. But in every city that has tried to reconcile high density and the automobile, failure has come swiftly, even where the authorities have launched into the construction of speedways with little if any consideration for the local historical and architectural heritage. That was the case in Asian cities: in Japan, then in the countries that developed rapidly in the 1970s (especially Singapore, Hong Kong, Taipei and Seoul) and now in China and the emerging countries of Southeast Asia. The upshot has been the same everywhere: as soon as the rate of car ownership reached a high threshold, the road system proved unable to absorb the increase in traffic. The cities had to move quickly to build up a public transport system, which gradually took increasingly large chunks of market share from the automobile. So one is inclined to conclude that the box in the top right-hand corner of the table below (Fig. 4) is impossible to put into practice and that sustainable urban development is fundamentally incompatible with the automobile-dependent city.
- Fig. 4: Natural environment, urbanity and sustainable development
Owing to the relative lack of consensus on mobility issues and the difficulty of working them into a traditional left-/right-wing opposition, these issues give rise to political stances which are at once forceful and unstable, and which are representative of a wider debate over urban planning models. The diagram below (Fig. 5) shows the principal possible alliances between the three approaches to nature (see Fig. 1 above) on mobility issues.
- Fig. 5: Approaches to nature and alliances on mobility issues
The formulas that look like the immediate stakes of the current debate – the right to mobility as against the valorization of immobility, alternative mobility incorporating every mode of transportation, whether public or private, as against the individual car or the defense of transportation modes inimical to intra- or inter-city public metrics – can actually be construed as points of equilibrium in tension. This makes it easier to understand how expressions that are not readily intelligible, such as “alternative mobility”, do actually make sense as hybrid formulations of conflicting principles. There is hardly any doubt that these alliances are partly based on ambiguities which the dynamic of public debate will eventually resolve. There are variations and inflections according to the country and prevailing circumstances, but on the whole this schema applies to every society on the planet – as do all the major debates about the sustainable city, for that matter.
The sustainable city is a city that accepts itself as such
Europe may be considered the part of the world that has made the most spontaneous commitment to the systematic project of sustainable urban development, which is consistent both with its urban history (to Europeans, the compact city is the “natural” embodiment of urbanity) and its political history (with a strong tradition of public regulation). Nonetheless, the preservation of architectural heritage, another domain in which Europe has long been at the vanguard, can also backfire on sustainability by making it difficult, even impossible, to make any changes at all to the physical configuration of a city, e.g. by increasing its density. The sacralization of the “house in the suburbs”, for example, or, more generally, the deep freeze on industrial-age buildings can ultimately prevent the urbanization in situ of suburban areas, undermine the capacity to invent new polarities outside the historical centers and push urban development outwards towards the remote environs.
One powerful approach, which is widely, albeit not unanimously, embraced, may be summed up in the formula: the city is sustainable development. In other words, the best way for the urban world to develop principles of sustainability is to accept itself as an arrangement based on urbanity, to move boldly forward along these lines without apologizing, without stalling. It is by refocusing on its primary vocation that urbanity can be more effective and more productive even while showing more solidarity for the world and more respect for the environment. That also means that, among existing or potential urban configurations, the city, defined as the archetype of urbanity par excellence because it imposes the least constraints on the dynamic of the density/diversity dyad, seems to be the most consistent choice.