Exergy and the Economic Process

Physical work generation requires the existence of a heat gradient, according to the universal notion of the Carnot Heat Engine; also the corner stone of the exergy concept. Heat gradient availabilities fundamentally drive systems' evolution. However, exergy is consumed irreversibly, via its gradual transformation to entropy. Extending Roegen's postulations [16], it is argued that exergy consumption founds economic scarcity, via: (a) human difficulty to produce large heat gradients on the Earth and (b) irreversible depletion of existing ones. Additionally, in the emerging Anthropocene epoch, exergy upgrades to a core concept for interpreting thermodynamically natural resource degradation and energy paradigm transitions.