Dr. Erik Gómez-Baggethun
Institute of Environmental Science and Technology, Universitat Autònoma de Barcelona)

We identify theoretical issues and operational challenges for current efforts to incorporate the value of ecosystem services in economic planning and decision making. Operational challenges addressed include 1) double counting, 2) non-linear dynamics. First, double counting problems emerge from the synergies and trade-offs in ecosystem services delivery. Substantial problems result from the attempt of extrapolating accounting models designed for economic goods to complex interrelated systems of ecosystem functions. We stress the limits that accounting models are meeting in their quest to develop ‘well defined ecosystem service units’ by artificially treating as discrete items what in reality are overlapping ecological processes. It is argued that the focus should shift from efforts to define single ecosystem services to ecosystem service bundles produced by service providing units with ecologically consistent boundaries. Second, conventional economic valuation bas ed on marginal analysis is misleading when ecosystems are close to thresholds and small changes may lead to abrupt loss of ecosystem services. It is suggested that in such situations information guiding ecosystem service management should move from monetary values to early warning signals based on biophysical indicators. Two theoretical issues are raised: 1) value incommensurability, 2) com-modification. The notion of value incommensurability, that is, the idea that the distinct value dimensions involved in ecosystem valuation may not be reduced to a single measurement unit, e.g. money, energy, land, or labor. The idea that failure to preserve ecosystem services can be tackled through their pricing and articulation through markets is discussed critically in the light of this theoretical stand. It is argued that, whereas money has become the hegemonic valuation language, decision making in ecosystem services management entails dealing with conflicting and often irreducible values. C losely related to this issue, the second issue relates to com-modification. The emphasis is put in the loss of information that results from masking diverse ecological processes behind the homogeneity of monetary figures, and the changes that result in human-nature relations. It is argued that if the perception of ecological elements and processes as exchange values becomes normalized, ecosystem functions lacking direct economic value may tend to become invisible in decision making. The last section of the paper discusses implications of the above identified issues for ecosystems services science and related design of environmental policy instruments.