Carlos Castilla Gutiérrez, Ph.D., Departamento de Economia de Las Instituciones, Estadística Económica y Econometría, University of La Laguna, Campus de Guajara, La Laguna, 38071, Spain
The first objective of an economic system is to meet human needs, using the resources in the best way it is possible to do so. But, as we can see, the most important of human needs, feeding, hasn´t been reached till the present as a result of a poor or bad distributed food supply. We have a similar situation in other basic needs like water or energy. Adding to this, resource scarcity and damage to the environment increase, bringing more difficulties to the economic process. In this context , the discussion on human needs, the resources and demographic trends become urgent. This paper intends to centre the discussion from a sustainable perspective, giving some relevant data and indicators. Most of the data presented come from the United Nations and other International Institutions and from researches in specific indicators related to the carrying capacity of the planet, nations or regions. Finally, the concept of irreversibility plays an important role in clarifying the cost of the different path to an equilibrium. By his hand, the ethical dimension is also remarked as a necessary basis to choose between the different options presented.