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Formal Comment

Formal Comment Formal Comments are critiques of specific published articles.

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The Ecological Footprint Remains a Misleading Metric of Global Sustainability

  • Linus Blomqvist mail,

    linus@thebreakthrough.org

    Affiliation: Breakthrough Institute, Oakland, California, United States of America

    X
  • Barry W. Brook,

    Affiliation: The Environment Institute and School of Earth and Environmental Sciences, The University of Adelaide, Adelaide, South Australia, Australia

    X
  • Erle C. Ellis,

    Affiliation: Department of Geography and Environmental Systems, University of Maryland Baltimore County, Baltimore, Maryland, United States of America

    X
  • Peter M. Kareiva,

    Affiliation: The Nature Conservancy, Seattle, Washington, United States of America

    X
  • Ted Nordhaus,

    Affiliation: Breakthrough Institute, Oakland, California, United States of America

    X
  • Michael Shellenberger

    Affiliation: Breakthrough Institute, Oakland, California, United States of America

    X
  • Published: November 05, 2013
  • DOI: 10.1371/journal.pbio.1001702

The Formal Comment by Rees and Wackernagel [1] raises our concern that this exchange will confuse readers. For this reason, we aim to emphasize a few key points that we believe cannot be disputed. First, the entire global ecological overshoot (footprint of consumption in excess of biocapacity) results from carbon dioxide emissions reframed as the hypothetical forest area needed to offset these emissions. Plantations of fast-growing trees would, by-the-numbers, eliminate the global overshoot. Second, the ecological footprint's (EF) assessments for cropland, grazing land, and built-up land are unable to capture degradation or unsustainable use of any kind. Finally, we conclude from the above and the points made in our original paper [2] that we would be better off discussing greenhouse gas emissions directly in terms of tons of CO2-equivalent (and thus focus on solutions to emissions), and developing a more ecological and ecosystem process framework to capture the impacts humans currently have on the planet's natural systems. The appropriate scale for these indicators will, in many cases, be local and regional. At this level, the EF is a measure of net exports or imports of biomass and carbon-absorptive capacity [3]. Any city, for example, would show a deficit, as it relies on food and materials from outside. That in itself, as Robert Costanza has noted, “tells us little if anything about the sustainability of this input [from outside the region] over time” [4].

Author Contributions

The author(s) have made the following declarations about their contributions: Wrote the paper: PK LB EE BB TN MS.

References

  1. 1. Rees WE, Wackernagel M (2013) The Shoe Fits, but the Footprint is Larger than Earth. PLoS Biol 11 (11) e1001701 doi:10.1371/journal.pbio.1001701.
  2. 2. Blomqvist L, Brook BW, Ellis EC, Kareiva PM, Nordhaus T, et al. (2013) Does the Shoe Fit? Real versus Imagined Ecological Footprints. PLoS Biol 11 (11) e1001700 doi:10.1371/journal.pbio.1001700.
  3. 3. van den Bergh JCJM, Verbruggen H (1999) Spatial sustainability, trade and indicators: an evaluation of the “ecological footprint”. Ecol Econ 29: 61–72. doi: 10.1016/s0921-8009(99)00032-4
  4. 4. Costanza R (2000) The dynamics of the ecological footprint concept. Ecol Econ 32: 341–345.