Ecological Indicators 37 (2014) 81–89 Contents lists available at ScienceDirect Ecological Indicators j o ur na l ho me page: www.elsevier.com/locate/ecolind Review Advancing quantification methods of sustainability: A critical examination emergy, exergy, ecological footprint, and ecological information-based approaches Ali Kharrazi a,∗ , Steven Kraines b , Lan Hoang c , Masaru Yarime a a Graduate School of Public Policy, The University of Tokyo, Tokyo, Japan b Future Center Initiative, The University of Tokyo, Tokyo, Japan c Centre for Sustainable Development, University of Cambridge, Cambridge, United Kingdom a r t i c l e i n f o Article history: Received 10 March 2013 Received in revised form 7 October 2013 Accepted 9 October 2013 Keywords: Sustainability quantification Emergy Exergy Ecological footprint Ecological information-based approach Resilience a b s t r a c t Sustainability is increasingly used to describe a paradigm for shaping the social and economic future of mankind. While the concept of sustainability remains elusive, various attempts to construct a framework towards the quantification of sustainability have been made. In this paper, we review the attempts of emergy, exergy, ecological footprint, and the ecological information-based approach towards quantifying the concept of sustainability. Specifically, we review these methods based on their ability to address three criteria namely, the integration of ecological and economic dimensions, the long term resilience of a system, and the consideration of both extensive and intensive properties, e.g. properties that depend on system size and properties that do not. This paper is intended to provide a base for advancing the development of better methods for quantifying sustainability. © 2013 Published by Elsevier Ltd. Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 00 2. Emergy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 00 3. Exergy analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 00 4. Ecological footprint analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 00 5. Ecological information-based approach . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 00 6. Synthetic analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 00 7. Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 00 Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 00 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 00 1. Introduction Sustainability is widely recognized as a paradigm upon which future policies must be based. However, a universally accepted def- inition for sustainability still has not been established, making it hard to systematically compare alternative policies. We suggest that a holistic approach that addresses the interactions between the dimensions of the concept of sustainability while providing a common ground for policy assessment is critically needed. ∗ Corresponding author. Tel.: +81471364877. E-mail address: alik@sustainability.k.u-tokyo.ac.jp (A. Kharrazi). To achieve such a holistic approach to sustainability, a method must be developed for measuring sustainability as a holistic met- ric at the system level. For example, most existing conceptual tools for quantifying sustainability are based on identifying quantitative indicators along ecological and economic dimensions, which are quantified separately or aggregated into a single numerical value (Lopez-Ridaura et al., 2002). This reductionist approach leads to a fragmented assessment which treats sustainability dimensions as uncorrelated factors. While a holistic approach may result in loss of information about details of each of the individual dimensions, creating a holistic system-level image of the interactions between the dimensions is critical for quantifying sustainability. The chal- lenge then is to construct tools that can quantitatively integrate both dimensions. 1470-160X/$ – see front matter © 2013 Published by Elsevier Ltd. http://dx.doi.org/10.1016/j.ecolind.2013.10.003