Section: Scientific Foundations

Environmental impacts of urban policies

One of the major issues in sustainbaility policy at the local/regional scales relates to the use of resources generated by the activity present on the considered territory, in particular in urban areas, considering their direct dependence on vast and sometimes distant territories and resources. In particular, quantifying the nature of local or distant impacts related to this activity is a major challenge both in terms of used resources and emitted pollutants.

To address this issue, one needs to correctly assess all flows, production and consumption of matter and energy on the territoriy. Without a sufficiently detailed characterization of the use of matter/energy, not only by type but also by origin and destination, the associated impacts cannot be correctly grasped by stakeholders and decision makers. This question is critical in a context where a factor of 4 of reduction of both energy and material use is advocated by various institutional agencies (e.g., the European Environmental Agency). Furthermore, in order to develop environmental policies (in particular urban policy) that do not result in a transfer of problems, either from one resource to another or from one territory to another, one needs to be able to assess policy options not only in terms of trade-off between societal issues (bearing, e.g., on activity location and transport needs) but more broadly by including also society-environment or environment-environment trade-offs (bearing, e.g., on greenhouse gas emission abatement policies and their potential indirect impacts on other environmental issues such as land and water use).

Such a description of the “metabolism" of a territory is made difficult by the structure of presently available statistics, either at the national or at more local scales. Indeed, such statistical tools focus much more on monetary than material and physical aspects, a bias that is easily understood as these tools were created in a context of (still) virtually infinite natural resources. This type of research requires to collect data from a large variety of sources (e.g., transportation ministry, INSEE, Agriculture Ministry, various professionnal organizations...) and to adapt methodologies of material flow analysis and associated impact characterization, that already exist at the national or european level, to more local administrative and geographic units.

Without incorporating this type of impact assessment, the policy decision-help provided by intergrated urban models described above miss their main objective of characterization of urban planning policies in terms of sustainability issues. In this respect, developing multi-criteria decision-help tools drawing on both types of analyses (integrated urban modelling and integrated urban environmental impact assessment) is an important long-term objective of the STEEP team.