BEFESA

Sustainable development is defined as the "development that is capable of meeting existing needs without compromising the resources and possibilities of future generations"⁽¹⁾.

This is the most popular and most complete definition of sustainable development.

_{(1) Report by the World Commission on Environment and Development (Brundtland Commission): Our Common Future UN (11/12/1987), Chapter 2, Page 43.}

In order to provide a more specific definition, the following aspects should be highlighted:

• There should be no unreasonable loss of any natural resources: minerals, fuel, timber…
• There should be no significant damage done to natural systems: forests, animals, water, aquifers, air...
• There should be no significant deterioration to the social stability: large dams that force major populations to relocate, river diversions that create deserts over important expanses of terrain, large lakes that are dried up…

_{D. Pearce, A. Markandya and E. B. Barbier, Blueprint for a Green Economy (London, Earthscan Publications, 1989).}

According to the scientific community, there will be a substantial increase in the world’s population in the coming years, reaching some 8.0 B people within 20 years, and 11.0 B by 2050. This situation will have important consequences on the environment:

• An increase in industrial and domestic waste levels.
• A significant increase in energy demand. This will not only create a problem in terms of how to meet this demand, but if the appropriate measures are not taken, it will lead to a significant increase in greenhouse gas emissions and the greenhouse effect.

It is therefore important to provide feasible solutions to each of these problems, including the climate changes.