A contribution to the search for a thermodynamics-based sustainability indicator: Extended Exergy Analysis of the Italian system (1990–2012) and comparison with other indicators

Sustainable growth is one of the major challenges of the XXI century; the antagonism between the needs of “development” and finiteness of natural resources is more and more evident, forcing international Agencies to endorse a “2030 Agenda for Sustainable Development” to promote, among other goals, a responsible management of natural resources. The key issue here is the lack of a consistent sustainability indicator to assess whether a country is moving in the right direction: for over seventy years, the Gross Domestic Product (GDP) has been the main parameter to verify the “health” of a Society, but this is a controversial issue in the scientific community. The main concern expressed by Economists and Energy experts is that the GDP was conceived to evaluate the “marketable part” of a society being in contrast with either a sustainable development and a responsible exploitation of natural resources. According to its critics, developmental scenarios built on the GDP might in fact be unsustainable and extremely harmful for future generations. Against this background, several indicators were developed with the intention of replace or supplement such a purely monetary quantifier, but these efforts enjoyed little success, so that the GDP is still the tool of choice for governments and most international Agencies. The aim of the paper is to assess whether it is possible to use a sustainable indicator based on the Extended Exergy Analysis (EEA), a Second Law-based accounting method that includes a novel internalization of Externalities (Capital, Labour and Environmental Cost). The present study proposes a structured method to perform an Extended Exergy Analysis of a whole country, starting with a very disaggregated database that ensured higher accuracy. A numerical application to the “System Italy” is implemented over a period of 22 years (1990–2012). The results lead to a complete divergence between the trends of GDP and EEA. Quite on the contrary, the EEA results are consistent with those generated by other sustainability indicators and contain a higher information content.