More inequality means less biodiversity

by Daniel Spitzberg | Economic inequality, one of the emerging issues in globalization, and biodiversity loss (the extinction of plants and animals) are two trends raising concern worldwide. By investigating these issues concurrently, a team of McGill researchers discovered that economic inequality has significant consequences for the environment.

"Biodiversity has been one of the hottest topics in the last 15 years," says Dr. Andrew Gonzalez, a professor in the department of biology and McGill School of Environment, and a Canada Research Chair in biodiversity. "Trying to explain why it is disappearing worldwide has been a pursuit of purely natural science, but investigating the drivers of species extinction requires a wider perspective." The study appears in the May 16 issue of PLoS ONE, journal of the Public Library of Science.

To take a broad approach to the problem, the researchers looked at indicators of income inequality and biodiversity loss over several decades. New, high-quality data was taken for two different scales: among 45 countries worldwide, and among 45 states within the United States. To make sound comparisons, the researchers controlled for differences such as area and climate, human population size, and per capita consumption.

The bad news: Societies with more unequal distributions of income experience greater loss of biodiversity. The good news: A reversal is possible. "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 other species," says Dr. Greg Mikkelson, professor in the McGill School of Environment and the Department of Philosophy. "While there is often a trade-off between economic growth and environmental quality, this study suggests that there is a synergy between a different kind of economic development—namely, toward a more equitable distribution of wealth and the conservation of biological diversity."

Dr. Garry Peterson, a professor in the School of Environment and Department of Geography, and a Canada Research Chair in social-ecological modeling, explains that if the United States were to achieve levels of income equality comparable to those of Sweden, the pattern reported in their paper implies that the number of plant and vertebrate species in danger of extinction would drop by 44 percent.

To propose reforms for economic equality that will protect biodiversity, however, requires further research.

Mikkelson and his colleagues will continue their research by investigating specific mechanisms that operate on the individual, social, and institutional level. They are hopeful that underlying mechanisms can be identified since the connection between economic inequality and threatened species is strong at both country and state levels of analysis.

One mechanism the researchers have considered is based on people's perceptions of inequality. In countries with widespread poverty and a small class of wealthy individuals, the poor population may exploit the environment to compete for the higher living standard they see around them.

"We already understand the impact run-away logging has on forests," says Gonzalez. "When loggers in Mexico cut down trees to make way for cattle ranches, the impact on forests is partly driven by Mexico's highly uneven distribution of wealth."