The term ‘carbon footprint’ has become tremendously popular over the last few years and is now in widespread use across the media. 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-cycle analysis 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.

>>> Processes causing greenhouse gas (GHG) emissions benefit humans by providing consumer goods and services. This benefit, and hence the responsibility for emissions, varies by purpose or consumption category and is unevenly distributed across and within countries. We quantify greenhouse gas emissions associated with the final consumption of goods and services for 73 nations and 14 aggregate world regions. We analyze the contribution of 8 categories: construction, shelter, food, clothing, mobility, manufactured products, services, and trade. National average per capita footprints vary from 1 tCO2e/y in African countries to 30t/y in Luxembourg and the United States. The expenditure elasticity is 0.57. The cross-national