In recent years, the economy has determined the agenda when environmental issues are concerned using cost/benefit analyses. This inevitably leads to wrong decisions because the uncertainties of the cost/benefit analyses are often magnitudes higher than that estimated by the economists. Therefore, these analyses should be replaced or supplemented by the concept of sustainability to aid the decision-making process. This book represents the first attempt to apply eco-exergy, a thermodynamic concept used to describe the development of ecosystems, to express sustainability and use it in a non-ecological context.