[cross-posted at the Earth Forum]
Global threats to biodiversity are well documented and widely appreciated, yet the socioeconomic factors driving losses of biodiversity are still poorly understood. A potentially central factor in this equation is economic inequality, which has been shown to affect public health and has been linked to various environmental problems.
In a new paper in PLoS One, G.M. Mikkelson and colleagues from McGill University in Montreal asked how economic inequality may be related to biodiversity loss. They found that both among countries, and among US states, the number of plant and vertebrate species listed as threatened or declining by the IUCN increases substantially with the Gini ratio of income inequality. The latter statistic, applied to households at the country scale and families at the state scale, can theoretically vary between 0 and 1. A score of zero indicates that all households or families in a given society have exactly the same income, while one means that a single household or family earns all of the income.
The authors checked the robustness of the trends they found by testing whether the effect of income inequality remained significant after controlling for geography, and for the demise of communist regimes in certain countries. In both analyses among countries and among US states, the connection between income inequality and biodiversity loss persisted even after controlling for these factors, as well as biophysical conditions, human population size, and per capita GDP or income. According to the authors:
“In general, unless current trends toward greater inequality are reversed, it may become increasingly hard to conserve the rich variety of the living world. Conversely, if we can learn to share economic resources more fairly with fellow members of our own species, it may help us to share ecological resources more fairly with our fellow species.”
Original source (free content):
[Photograph: Rhinos grazing in Matopos National Park, Zimbabwe, by Philip Niewold]