Shared wealth or nobody's land? The worth of natural capital and ecosystem services

The prerequisite for a sustainable and equitable use of common resources (the so-called Commons) must be the proper evaluation of their role within the complex network of relationships that ensure ecosystems functioning, resilience, and evolutionary dynamics. It is crucial to ascertain to what extent the common wealth is used for the common benefit. Money-based schemes for valuing the Commons, such as the so-called "willingness-to-pay", provide a user-side evaluation perspective based on the idea that value only stems from utilization by humans. As a complement to such a point of view, we present and discuss in this paper a donor-side evaluation method (Emergy Synthesis) based on the idea that a proper measure of value can be achieved by also accounting for the work done by the biosphere in generating services and resources. It should not be disregarded that such resources and services also provide support to other species in the web of life. Emergy, a scientific measure of such environmental support, is suggested as a tool capable to assess quantity and quality of shared resources, thus providing a basis for their environmentally sound management. (C) 2010 Elsevier B.V. All rights reserved.