It’s easy to use a word so often that its meaning is taken for granted. Nuances are lost, conceptual freight laid aside, assumptions unexamined. Take biodiversity: just a few decades old, the word is now ubiquitous, a default frame for thinking about nature—and that’s not necessarily a good thing.

Writing in the journal Biological Conservation, environmental philosopher Freya Mathews of Australia’s Latrobe University challenges biodiversity: not its scientific meaning, but the way it’s used in policy settings. There the word is not just scientific but political, says Mathews, and “it drastically limits what conservationists may aspire to achieve.”

For Mathews, the problem with biological diversity, a concept first articulated in 1980 by conservation biologist Thomas Lovejoy and by the decade’s end synonymous with conservation, is an over-emphasis on type rather than instance. So long as there’s enough members of a given species to avoid extinction, or so long as representative examples of a given ecosystem exist, biodiversity’s policy requirements are met.

“This results in a tendency towards an ‘ecology of the minimal,’” writes Mathews, in which commitment is required only by the threat of disappearance. Ideals of abundance, wildness, and intrinsic worth are marginalized; specific plants, animals, and natural communities are devalued, making it difficult to “advocate on behalf of vast terrains of abundant life rather than mere remnants and last things.”

As an example, Mathews offers the Kimberley, a Germany-sized region of northwest Australia that’s home to few people, a great many wild things, and vast mineral and gas deposits. In recent years conservationists and resource extraction companies have squared off over the Kimberley’s fate—and in this battle, biodiversity as an organizing principle has offered little help.

“The gist of current biodiversity-based notions of conservation,” writes Mathews, “is that such abundance is surplus to environmental requirements. Viability might be assured with dramatically reduced populations.” It’s a lament familiar to many people who’ve wanted to protect their own special pocket of nature.

As an antidote, Mathews calls for “bioproportionality”—conservation goals set according to what would exist in the absence of industrial development. To be sure, these baselines would be contested, and Mathews’ critique will ruffle some feathers: a great many people are deeply inspired by the ideal of biodiversity, and in many instances it’s a very effective political principle.

Still, it’s useful to remember that biodiversity is but one measure of nature, and good to challenge habits of thought, especially at a time when so much of the natural world is at risk. “It is time then not to lower the ethical bar,” writes Mathews, “but to raise it to its true height.” —Brandon Keim | 27 July 2016