Introduction

The roots of the concept of sustainability can be found, according to various scholars, in two contributions, both published in 1972: a book by Meadows et al., namely The Limits to Growth, which modelled the dynamics of the human presence on the planet, and an article by Goldsmith et al., A Blueprint for Survival, which forecast “the breakdown of society and the irreversible disruption of the life-support systems on this planet” without profound social changes. Both agreed that “if current trends are allowed to persist” (Goldsmith et al. ibidem) the actual growth model is bound to collapse within a century and that a consensus has to be found at the global level involving governments, the private sector and public opin-ion leaders. Such statements underline the fact that sustainability, defined literally as the ability to maintain or support and, more broadly, as the ability to continue a cer-tain behaviour indefinitely, can be used as a key concept for the definition of devel-opment models to be pursued.