Since the last decades the term sustainability started to arise and form a different meaning from the widely used “environmental” term. In fact sustainability is about using the current resources but also provide with confident other resources to be used at the future. Sustainability is the keyword of the interaction of present and future need. Sustainable development has been defined on the Brundtland Report as “meeting the needs of the present without compromising the ability of future generations to meet their own needs.” (United Nations, 1987 p24). Sustainability can be simply defined, in a generic manner, as the ability to continuing something. Is a way of “forward thinking” and serving the needs of today and be able to provide adequate services at the future.
Sustainability can be divided in three main considerations investigating the environmental the economic and the social elements. All these must be considered in order to achieve a clear identification of sustainability for each subject. In recent decades, remarkable results have been achieved in the environmental aspect of sustainability. Many feel that achieving the broader goals of sustainability is still a distant objective, since many problems appear extremely difficult to deal with, such as obtaining large reductions in the emission of greenhouse gases and in particular. Furthermore, the scope of the term of sustainability has been defined in such a way so that to describe a variety of goals, including a healthy environment, a healthy society and a healthy economy – the three objectives of sustainability.