The logical foundations of ecological footprints

An academic debate about ecological footprints has started at last. It was set in motion by a critical article in Ecological Economics, 29(1), 61-72, by Jeroen C.J.M. van den Bergh and Harmen Verbruggen (henceforth B&V). Being ourselves major users of ecological footprints, we disagree with most of the criticisms that B&V level at the concept. In our experience, there are widespread misunderstandings surrounding the methodology of eco-footprinting, so it seems a good time to set out the logical foundations of eco-footprinting for all those who may have an interest in the subject - surely extending beyond the readers of Ecological Economics. Thus our approach will be a general exposition. However, even those who have not read the article by B&V will doubtless benefit from knowing the sort of criticisms which are made against ecological footprints, so we will also attempt to explain and respond to the criticisms raised by B&V.