ABSTRACT
The chapter of the book starts with a simple thermodynamic approach to the concept of sustainability and the definition of the concept of a dynamic sustainability, which is driven by the constant energy flux coming from the sun. This energy flow, in absence of relevant anthropogenic activities, drives the planet towards a state of increased energy and abundance of resources. Contrary to that the state of pollution, unsustainability and environmental disruption, is therefore linked to a decreased energetic state of the planet through the chemical energy associated to the state of formation of the elements composing the biosphere.
This chapter of the book proposes a link between sustainability to the exergy level of the Earth. In particular, nonsustainable practices lead to a decrease of the exergy of the Earth (and eventually to the exergetic death of the planet, while sustainable practices would lead to a gradual increase in the Earth energy, to a state of abundance. The sustainability challenge is therefore related not only to the elimination of fossil fuel dependence but also to the recovery and management of the exergy levels in the biosphere. Unfortunately, these have been gradually reduced because of the pollution caused by anthropogenic resources and because of the gradual shrinking of the biosphere volume.
