Data accuracy in Ecological Footprint's carbon footprint

Since the UNCED's call for the creation of sustainability indicators many such have been put forth in the literature. One of the more successful ones, in terms of popularity, is the Ecological Footprint (EF). Much criticism has been directed at the EF, not least the carbon uptake component (CF). The CF typically makes up around 50% of global EF and is the sole cause for its overshot - i.e. results indicating unsustainable consumption. The aim of this study was to assess the accuracy of the data used for the calculation of CF. The study finds that the data is lacking in accuracy to the point that stating that CF or EF is any given number at any given time is misleading. The reasons for this uncertainty are identified as use of estimates and averages for the calculations as well as discrepancy between data collected locally and data from international databanks. CF or EF results should thus always be prefaced with caveats regarding the uncertainty involved in the estimation. The lack of caveats in EF dissemination is worrying and has led to the most serious criticism of the method to date, that of it fulfilling the criteria for pseudo-science for failing to disclose uncertainties in calculations and results. This study suggests that the reason for this failure may be traced to the Global Footprint Network (GFN) being both a think tank actively promoting the use of EF, and the world's largest research unit into the methodology. This can lead to uncertainties being down played in dissemination not to confuse current users of the method or dissuade new ones. The study further raises questions about the accuracy of GHG estimates in general since they are often based on the same IPCC default emission factors and activity data as used by the GFN.