NEWS AND VIEWS On the bioproductivity and land-disturbance metrics of the Ecological Footprint Manfred Lenzen a, ⁎ , Carina Borgstrom Hansson b , Stuart Bond c a ISA, A28, The University of Sydney NSW 2006, Australia b WWF Sweden, Ferievägen 22, Lund S-224 67, Sweden c WWF-UK, Panda House, Weyside Park, Godalming, Surrey GU7 1XR, UK ARTICLE INFO Article history: Received 15 September 2006 Received in revised form 10 November 2006 Accepted 10 November 2006 Available online 22 December 2006 1. Introduction Since the Ecological Footprint was invented, research groups around the world have adapted the concept to their particular circumstances. In particular, researchers have used different metrics that pertain to different research questions (Lenzen and Murray, 2003). For example, while the metric used by the organisers of the Global Footprint Network (GFN) expresses bioproductivity requirements 1 in global hectares, an Australian approach examines land disturbance in disturbed hectares. In short, – bioproductivity reflects the amount of biological productivity required to renew the biotic resources humans use (food, timber etc) and to absorb their waste (mainly compensate for their CO 2 emissions from energy use). This bioproductivity is measured in “global hectares”, representing an area of world- average biological productivity, including both land and ocean. Global hectares are calculated from actual hectares by weight- ing with yield factors and equivalence factors (Wackernagel et al., 2005; Wiedmann and Lenzen, 2007-this issue) 2 ; – land disturbance reflects the current and projected future impact on land of human consumption of biotic and abiotic resources (food, timber, minerals, water etc), and emissions of all greenhouse gases from all sources, using as a proxy the deviation of the biodiversity of vascular plants from a pristine condition. Land disturbance is expressed in “disturbed hectares”, calculated from actual areas by weighting with factors describing the degree of disturbance (Lenzen and Murray, 2001, 2003). 3 The aim of this note is to follow up on discussions at the recent Ecological Footprint Forum in Italy (2006). 4 In particular, we will highlight a number of situations, where managing for bioproductivity alone may lead to counter-productive incen- tives. We conclude that in these cases, the bioproductivity ECOLOGICAL ECONOMICS 61 (2007) 6 – 10 DOI of original article: . doi:10.1016/j.ecolecon.2006.10.018. ⁎ Corresponding author. E-mail addresses: m.lenzen@physics.usyd.edu.au (M. Lenzen), carina.borgstrom-hansson@wwf.se (C. Borgstrom Hansson), sbond@wwf.org.uk (S. Bond). URL: http://www.isa.org.usyd.edu.au. (M. Lenzen). doi:10.1016/j.ecolecon.2006.11.010 available at www.sciencedirect.com www.elsevier.com/locate/ecolecon