Ecological Indicators 69 (2016) 224–232 Contents lists available at ScienceDirect Ecological Indicators jo urnal homepage: www.elsevier.com/locate/ecolind Questioning the Ecological Footprint a,1 b,c d d,2 Alessandro Galli , Mario Giampietro , Steve Goldfinger , Elias Lazarus , d,2 e,c d,2 f,∗ David Lin , Andrea Saltelli , Mathis Wackernagel , Felix Müller a Global Footprint Network, 7-9 Chemin de Balexert, 1219 Geneva, Switzerland b Institució Catalana de Recerca i Estudis Avanc¸ ats (ICREA), Passeig Lluís Companys 23, 08010 Barcelona, Spain c Institut de Ciència i Tecnologia Ambientals (ICTA), Universitat Autònoma de Barcelona (UAB), 08193 Bellaterra, Spain d Global Footprint Network, 312 Clay Street, Suite 300, Oakland, CA 94607-3510, USA e Centre for the Study of the Sciences and the Humanities (SVT) – University of Bergen (UIB) Norway f Institute for Natural Resource Conservation, University of Kiel, Olshausenstrasse 75, D 24118 Kiel, Germany a r a t i c l e i n f o b s t r a c t Article history: In this perspective paper a critical discussion about the concept of the Ecological Footprint is documented Received 4 January 2016 based on 10 questions which are answered from critical and supporting points-of-view. These key ques- Received in revised form 23 March 2016 tions are directed toward the underlying research objectives of the approach, a comparison with similar Accepted 4 April 2016 concepts, the quantification methodology and its accuracy, the characteristics of the observed flows, the role of scales and resolutions, the implementation of food security, the utility of the ecological footprint Keywords: for society, the political relevance of the concept and the differences from other international indicator Footprint relevance systems. Footprint methodology © 2016 Elsevier Ltd. All rights reserved. Footprint applicability Footprint utility Footprint critics 1. Introduction and targets and widening the knowledge in the respective field of science. Scientific debates are focal elements of progress in research Indicators provide aggregated and simplified information on and development of academic conceptions and methodologies. phenomena which often are hardly directly determinable, and as According to the strong epistemological tradition which demar- such they are suitable objects of intensive debates: Their defini- cates science from other endeavors, the capacity to progress by tions, the relations to the indicandum, the elaborated methodology successive refutations and rectifications is a focal element of sci- and its transparency, the respective measurements and collec- entific discussions. Although they are sometimes executed in an tions, the produced results and their interpretations are often obstinate and less tolerant atmosphere, the outcome can be a pro- related with certain inaccuracies and uncertainties. Furthermore, ductive “cross fertilization”, opening the objects of research for new the contextual extents of indicators as well as their degrees of aspects, setting new questions, demanding for adapted concepts aggregation provide a wide field of problems, challenges, potential ambiguities, normative loadings and, consequently severe discus- sions. In the following, unusual article, a hopefully constructive step in the scientific debate about the Ecological Footprint is made: The ∗ Corresponding author. Tel.: +49 431 8803251; fax: +49 4318804083. paper is based on the exchange of several letters, replies and articles E-mail addresses: [email protected] (A. Galli), in which conceptual and methodological aspects of the Ecologi- [email protected] (M. Giampietro), [email protected] cal Footprint have been discussed in this journal (see Giampietro (S. Goldfinger), [email protected] (E. Lazarus), [email protected] (D. Lin), [email protected] and Saltelli, 2014a,b; Goldfinger et al., 2014; Lin et al., 2015 and (A. Saltelli), [email protected] (M. Wackernagel), additionally van den Bergh and Grazi, 2015). To avoid a long-term [email protected] (F. Müller). sequence of papers the authors agreed to produce this joint per- 1 Tel.: +39 346 6760884. 2 spective article. It aims to shed light on the roots of ongoing critical Tel.: +1 510 839 8879. http://dx.doi.org/10.1016/j.ecolind.2016.04.014 1470-160X/© 2016 Elsevier Ltd. All rights reserved. A. Galli et al. / Ecological Indicators 69 (2016) 224–232 225 discussions regarding the Ecological Footprint and its methodol- of ecological processes (with no consideration for the dam- ogy. This has been boiled down to ten key questions by which we age to the environment) and massive injections of fossil energy identify strengths and limitations of the Ecological Footprint from based inputs (entailing the depletion of a non-renewable stock). different perspectives. Therefore, in this article the authors do not Therefore, what is measured in the Ecological Footprint proto- agree with the overall contents; In the opposite, the paper is docu- col under the label “biocapacity” is not an assessment of how menting basic disagreements. One perspective is offered by Mario much can be produced on this planet according to its ecological Giampietro and Andrea Saltelli. The other perspective is presented limits. by researchers associated with Global Footprint Network: David Basing upon these general contradictions, both parties sug- Lin, Mathis Wackernagel, Alessandro Galli, Elias Lazarus, and Steve gested five questions each to frame the discussion about the validity Goldfinger. Both parties suggested five questions each to frame the and the utility of Ecological Footprint accounting. Both parties have discussion about the validity and the utility of Ecological Footprint answered all questions. accounting. Each perspective is offering their particular answers for all 10 questions. 2. Key questions This paper starts from a common point of departure. Both par- ties recognize that it is fundamental for policy formulation and 1. What underlying research question does the Ecological Foot- 4 monitoring to have a quantitative approach capable of measur- print address? ing human demand on nature against nature’s ability to provide Giampietro and Saltelli Lin, Wackernagel, Galli Goldfinger, ecological services. The position of Global Footprint Network is and Lazarus that Ecological Footprint Accounting adds up ecological services The mathematical protocol Ecological Footprint accounting people demand in as far as they compete for biologically produc- developed by the Global addresses one key question: How 3 tive space. According to this claim the Ecological Footprint can Footprint Network (GFN) much of the biosphere’s regenerative be compared against the available bioproductive area which pro- aims to assess man’s impact capacity do human activities on the planet and wishes to demand? This measure can then be vides these services – biocapacity for short (Borucke et al., 2013). achieve this by aggregating compared to the biosphere’s Giampietro and Saltelli (2014a,b), on the contrary, argue that the across scales and available regenerative capacity. By claim of Global Footprint Network does not stand scrutiny and that compartments, while at the doing so, the Ecological Footprint the Ecological Footprint is not a quantitative approach capable of same time focusing on a framework accounts for (1) the measuring human demand on nature against nature’s ability to subset of the relevant magnitude of humanity’s physical dimensions of man’s impact. metabolism and (2) the demand provide ecological services, and that the results generated by this Thus the measures arrived at such metabolism places on the methodology are not useful. This divergence of opinions led to the by the Global Footprint Earth’s ecosystems. Thus, it present paper. Network – the quantitative captures a necessary, but not The differences between the basic attitudes of the co-authors assessments labeled as sufficient, condition for “Ecological Footprint” and sustainability. are already visible by focusing on the basic definitions: “Biocapacity” – have a The Ecological Footprint The Footprint Network provides the following terminology: purported resemblance with framework is not a measure of Ecological Footprint accounting answers the question: How much the regenerative and total human impact but a proxy for of the regenerative capacity of the biosphere is occupied by human absorptive capacity of the human pressure on ecosystems. demand? Humanity’s Ecological Footprint is the sum of all biolog- biosphere but no descriptive In concept, the Ecological Footprint power. is the sum of ecosystem services ically productive surfaces of the planet for which all the human A research question on man’s used by humans, to the extent that demands compete. These biologically productive surfaces renew impact on the planet is asked these services occupy mutually resources, provide services such as carbon sequestration, or accom- and left unanswered, while a exclusive, biologically productive modate urban infrastructure. Human demand can be a single full metaphorical apparatus area. These services include is developed to communicate provision of resources, housing, activity, the consumption of one person, a city, a country or human- the result of this analysis as infrastructure, and absorption of ity as a whole. Ecological Footprints, or human demand (in a an overall measure of man’s that population’s waste, using given year) is compared to the amount of resources and ser-