In January, Andrew Dobson and colleagues published an article in Science about the international agreement to halt the loss of biodiversity by 2010.
They stressed the need for an index of the state of biodiversity that is as easily recognised and understood as gross domestic product (GDP) is as a measure of economic development (see Conserving biodiversity needs more than just biology).
In today's Science, however, Jurgen Brauer argues that GDP, while widely accepted, is not rigorous and can be easily misunderstood.
Brauer says GDP oversimplifies the causes and consequences of economic growth. For instance, economies can grow at a cost to the environment or as a result of increased military spending in times of war. Braun says GDP can be deceptive and warns of using a similarly simple index to describe patterns of biodiversity.
In a separate letter, Brian Czech and colleagues point out that the inverse of GDP could itself be a good indicator of the status of biodiversity. They demonstrate that, in the United States, growth of GDP since 1972 correlates well with increasing numbers of endangered species.
Dobson and his colleagues responded by clarifying their stance on GDP. Agreeing with Brauer, they point out that GDP's main failing as an indicator is that it amalgamates a number of different processes into a single figure.
They suggest establishing a set of indicators attuned to different aspects of ecological health, which could be compared to indices of economic progress.
Read more about biodiversity in SciDev.Net's biodiversity dossier.