The sustainable development concept has been firstly implemented in an official document, ‘Our Common Future’, written in 1987 by a commission created by the United Nations, and chaired by Gro Harlem Brundtland, who was the Prime Minster of Norway.
This document, also known as Brundtland Report, provides the following definition for the sustainable development: ‘development that meets the needs of the present without compromising the ability of future generations to meet their own needs’.
This idea involves living within the carrying capacity of the ecosystems, so as to avoid the resources utilisation rhythm being higher than the resources generation one, and the pollution quantity being superior to the quantity that the natural systems are able to absorb or neutralise.
In 1992, the sustainable development concept is widely spread within the Earth Summit, the United Nations Conference on Environment and Development held in Rio de Janeiro from June 3rd – 14th. Among the signed documents, ‘Agenda 21: The Global Alliance for Environment and Development’ is an outstanding one. It is an action plan for the first part of the 21st century and it is the base for a new global alliance for sustainable development and environmental protection.
Agenda 21, an extensive document of 40 chapters, is an action programme that promotes the sustainable development in three fundamental areas: the social, the economic and the environmental one. Therefore, its priority actions, among others, are: promoting the sustainable growth, the fight against poverty, the compatibility of the demographic dynamics and the sustainability, the efficient utilisation of the resources, the management of the chemical products and the waste, and the social participation and responsibility.
In the 28th chapter, the local institutions are urged to fulfil their responsibility and to start an open and participative dialogue with the citizens, the organisation and the entities in order to adopt an environmental and developmental action plan especially calculated for the local problems, opportunities and values, and intended to make municipalities more sustainable, habitable and fair.
This idea is practically implemented when the Aalborg Charter is approved and signed by the participant municipalities at the first European Conference on Sustainable Cities and Towns, which took place in Aalborg (Denmark) on May 27th 1994. According to the charter, the municipalities engage themselves in adopting local strategies and making sustainability one of the main pillars of their action. The commitment of the Aalborg Charter signatories (among them, there are more than 150 Catalan municipalities) consists of implementing the Agenda 21 at local scale, and following all its principles.
Although most of the consulted legal documents on the environment do not consider the demographic variables as an important factor when the environmental policies are implemented, we have found an interesting document that contains some reflections on it, despite it deals with the United States. It is a brief but complete study on the demographic variables that should be considered when setting up a policy, that is: the population volume and distribution, the age structure (with special interest on the aging), the ethnic composition of societies, the economic status, the migrations and the house composition.
To be precise, the main idea of the environmental policies with a demographic perspective should be intended, firstly, on studying whether the temporal evolutions of some significant variables from the environmental perspective, such as the energy consumption, the emission of contaminant and greenhouse gases, or the recycling, also respond to changes of volume, distribution and composition of the population, the differential behaviour of individuals according to their socioeconomic status, etc.; and, secondly, on analysing whether the territorial differences (interregional and inter-state) respond to a complex of causes, which would include the previously mentioned demographic variables.