What is 'footprint' in Antarctica: proposing a set of definitions

Footprint in Antarctica has become a common term in environmental research, yet after 25 years there is still no certainty about what it refers to. The closest Antarctic definition has been 'the spatial extent and intensity of disturbance'. Yet there is still confusion around what 'disturbance' footprint is actually measuring. This is demonstrated within Committee for Environmental Protection documents, with over 80 mentions of footprint, with at least eight different meanings since 1998. To improve clarity in its use by both scientists and policy-makers, we first examine the development of the term footprint, how it has been applied, and its usefulness in applications such as interpreting 'minor or transitory' activities. We then identify and define a suite of footprint types (disturbance, building, contamination, non-native species, noise, visual, visitation, risk, carbon, ecological, and human) with the aim of developing a common understanding around what the term is referring to. Our goal is to ensure the concept of footprint can be a useful environmental tool to facilitate progressing environmental protection.