The term ‘carbon footprint’ has become tremendously popular over the last few years and is now in widespread use across the media – at least in the United Kingdom. With climate change high up on the political and corporate agenda, carbon footprint calculations are in strong demand. Numerous approaches have been proposed to provide estimates, ranging from basic online calculators to sophisticated life-cycleanalysis or input-output-based methods and tools. Despite its ubiquitous use however, there is an apparent lack of academic definitions of what exactly a ‘carbon footprint’ is meant to be. The scientific literature is surprisingly void of clarifications, despite the fact that countless studies in energy and ecological economics
that could have claimed to measure a ‘carbon footprint’ have been published over decades.

This report explores the apparent discrepancy between public and academic use of the term ‘carbon footprint’ and suggests a scientific definition based on commonly accepted accounting principles and modelling approaches. It addresses methodological question such as system boundaries, completeness, comprehensiveness, units and robustness of the indicator.