The challenges of sustainability are becoming more complex, in part, because our increasing population demands ever more from the Earth to meet even our basic needs. But even though there is widespread awareness of the problems of sustainability, including overfishing, pollution, and habitat destruction, solutions typically neglect the goal of equity and instead pit economic against environmental benefits. Now, in an Early Edition PNAS paper, Halpern et al. have developed a theory to include social equity into conservation planning, providing a tool for consistently achieving what’s commonly referred to as the “triple bottom line” of equity, economic, and environmental benefits.
Intuitively, conservation efforts have little chance of success when the costs or benefits are unfairly distributed because self-enforcement is more likely when all parties perceive new regulations as fair. Because of this intuitive understanding, current conservation policies are written to avoid extreme inequity. But they often do not address equity (whether real or perceived) as an objective itself. That is likely because “in the conservation or spatial planning literature,” as the authors write, “there is no formal theory for addressing it.”
In their study, the researchers found that one difficulty in including equity in conservation planning is simply defining equity and measuring it. Adapting a mathematical tool typically used for measuring inequality of wealth (the Gini index), the researchers measured equity in terms of dissimilar costs and profits among the different entities in each of three case studies. In their California central coast case study, for example, the entities were eight commercial fisheries, and the researchers looked at the trade-offs between the total value lost by the fisheries, equity of losses among the fisheries, and conservation goals achieved through the creation of a network of marine protected areas (MPAs).
The authors conclude that incorporating equity into conservation planning may produce non-intuitive results with their theory as it is now, such as the elimination of MPAs in the California case study if equity is given a high priority compared with conservation (as measured by threat abatement, which the authors call a “proxy at best for true changes in conservation values and outcomes”). Still, if there is to be a systematic approach to achieving a “triple bottom line,” then it will be important to sort out the many proxies involved in such assessments, formalize and quantify equity, and fill in the gaps of our intuitive understanding of how equity influences conservation success. Defining the problem carefully and explicitly stating their assumptions, Halpern et al. have provided us with a starting point.
Achieving the triple bottom line in the face of inherent trade-offs among social equity, economic return, and conservation. Benjamin S. Halpern, Carissa J. Klein, Christopher J. Brown, Maria Beger, Hedley S. Grantham, Sangeeta Mangubha, Mary Ruckelshaus, Vivitskaia J. Tulloch, Matt Watts, Crow White, and Hugh P. Possingham. PNAS. Published online before print March 25, 2013, doi: 10.1073/pnas.1217689110