When their focus shifted away from mere survival, human beings began to create towns and cities for themselves. This led to the development of culture, commerce, and politics: all the trappings of civilization. Crafts were developed and goods were traded. The concentration of human beings in one place facilitated exchanges both of merchandise and of ideas; it also made some kind of power structure necessary. It is in today’s cities that virtually all the world’s economic and cultural activities are concentrated: New York and Tokyo each have an annual GDP in excess of a trillion US dollars.
Towns and cities are also places of passage, where people of very different origins come together. But this diversity is only partial: the urban model has no space for other models, such as the nomadic or the indigenous way of life. It is also highly stratified, in both social and spatial terms, and city-dwellers tend to only mix with people from a similar background or class. Above a certain size, large urban concentrations dehumanize social relationships. But by grouping people together, they also enable them to organize themselves and they make politics possible. The 1992 Earth Summit in Rio de Janeiro was already postulating that the best way to treat environmental questions is to ensure the participation of all the citizens concerned, at the appropriate level.
The model of participatory democracy practiced in the Brazilian city of Porto Alegre is frequently cited as an example of an alternative form of organization and government. The city set up local councils which enabled the residents to become involved in making any decisions that affected them directly; these councils were allocated a percentage of the city’s budget, so that they also had the means to carry out the decisions taken—many of which related to tackling social inequalities and protecting the environment. There were criticisms of this administration, particularly as its participants were drawn from only one section of the population; since it was not necessarily representative of the whole, it risked promoting individual interests. However, the Porto Alegre model was simply one form of representation among the many currently practiced in the world, all of which have both advantages and disadvantages.