New methodological insights into Ecological Footprint Accounting: flow vs stock distinction and carbon Footprint revision

Natural capital is the primary and fundamental pillar allowing humans to thrive on Earth and sustain the functioning of human society and economy. Several ecosystem services (i.e. of the kind of provisioning, regulating, supporting and cultural services) are the tangible benefit to humans and are generated by natural capital in the form of stocks and flows of resources. Fully understanding and evaluating these ecosystem services is thus crucial for tracking the consumption of natural resources and properly managing natural capital. This thesis presents an in-depth analysis of the Ecological Footprint methodology, which is one of the most popular environmental accounting tools able to evaluate ecosystem services from a biophysical perspective. Ecological Footprint is defined as the biologically productive surface required to provide a specific sub-set of ecosystem services humans demand. It is compared with the capacity of existing biologically productive surfaces to produce such ecosystem services (i.e. biocapacity). Despite its growing popularity, Ecological Footprint has been subject to critical views on its rationale, methodology, and policy usefulness. This thesis aims at addressing part of these criticisms, specifically those related to the method’s inability to track depletion of natural capital stocks as well as those concerning a specific component, the carbon Footprint. Since Ecological Footprint is currently a measure of the use of resources and services in their flow dimension, the thesis presents a preliminary analysis of the feasibility of implementing a measure of stock depletion within this methodology. As such, this thesis first provides a comprehensive description of Natural Capital as well as of resources’ stocks and flows and their multiple relationships. Then, Ecological Footprint is explored according to its methodological premises, rationale and unit of measure and conceptually investigated for implementing the distinnction of stock vs flow of resources in the accounting framework. This issue was found to be vast and more complicated than expected; as such the thesis concludes this part by setting up a research agenda with the needed future steps to guide research on this topic. Following this process of refinement and development, the thesis addresses the stock and flow distinction in one specific component of Ecological Footprint, the carbon Footprint. It represents the largest input on the overall result and a review process around its rationale, calculation steps and a key parameter (the Average Forest Carbon Sequestration, AFCS) is performed to increase transparency and accuracy of its accountings. As a consequence of this refinement process, a new AFCS value is provided according to accurate and reproducible dataset on forested surface and average biomass growth in forest. These results represent one of the major changes adopted in 2016 Edition of National Footprint Accounts, the main application of Ecological Footprint accounting at national and world level annually published by Global Footprint Network. As such, new results of carbon Footprint, as well as of total Ecological Footprint, have been tested at geographical level and compared at national level among countries. This analysis highlights the relevant implications of the consumer approach adopted by the Ecological Footprint to assign responsibility of CO2 emissions. Finally, thesis supports the policy relevance of the Ecological Footprint method and its carbon Footprint component in light of the Paris agreement, the treaty stipulated in December 2015 to combat climate change and limit temperature rise below 2°C by 2050. Despite acknowledged limitations and the need to keep improving the methodology of this relatively young accounting tool, Ecological Footprint could still represent a relevant monitoring tool to keep track of resources and help society flourishing within the limit of our planet.