In the footprints of LCA

dr. Reinout Heijungs

Department of Econometrics and Operations Research, VU University Amsterdam
Institute of Environmental Sciences, Leiden University

The worlds of footprints and life cycle assessment have lived separately for a long time, but with the advent of the carbon footprint as an LCA that addresses only climate change, the two worlds seem to assimilate. In this presentation, I will discuss some of the points where footprints and LCA agree, but also some of the points where they disagree.

Environmental footprints: Concept, classification, and the relevance to planetary boundaries

Kai Fang

Institute of Environmental Sciences, Leiden University

The concept of footprints has obtained a growing interest and discussion within the scientific and policy communities. In this presentation, environmental footprints are first defined from a broader point of view, with the aim to provide clarity on the underlying conceptual issues of accounting for footprint indicators. With respect to the ways in which various inventory flows (extractions or emissions) are aggregated to constitute a single-score footprint, the existing environmental footprints can be roughly classified into the inventory-oriented category and the impact-oriented category. Apparently, there is a need for a full understanding of the appropriate use and limitations of each footprint category, and the possible synergies between them.

The relevance of environmental footprints to planetary boundaries is discussed within a footprint-boundary environmental sustainability assessment framework. It is shown that footprints in aggregate have significant similarity to planetary boundaries in terms of the coverage of environmental issues. However, both of the two methods are found to be limited in their ability to handle sustainability issues, and therefore do not substitute but complement each other. Synthesizing footprints and boundaries is appropriate for use in assessing environmental sustainability at the national level, by benchmarking individual footprints against the corresponding national environmental boundaries. A comparative analysis of the world’s major nations is conducted, in which the environmental sustainability of national greenhouse gas emissions, freshwater use, and land use is measured and ranked on the basis of a dimensionless environmental sustainability pressure index.