Nature 455, 707-708 (9 October 2008) | doi:10.1038/455707b; Published online 8 October 2008

The Red List still matters


And the IUCN has more to offer than just data on the nearly extinct.

The International Union for Conservation of Nature, better known as the IUCN, is officially venerable. At 60, it is the oldest global conservation organization. Indeed, its best-known product — the Red List, a compendium of species threatened with extinction — may seem a bit outdated in 2008. After all, the lesson of ecology is that species don't exist in isolation. They evolve and persist because of their relationships with all the other species around them. Conservationists these days usually talk about ecosystems as the units of interest, rather than species.

This trend towards broader thinking has not been lost on the IUCN. This week in Barcelona, Spain, the union is holding one of its four-yearly meetings. On the agenda is the release of the latest version of the Red List, which the union has been keeping since 1963, and which now covers nearly 45,000 species. But the union has also authored an assessment of mammals that looks for larger patterns. For example, it turns out that marine mammals, and land mammals of south and southeast Asia, are in the worst shape — precisely the kind of knowledge that could help scarce conservation dollars go further (see page 717).

The IUCN is even getting into the business of predicting which species will one day become threatened as a result of climate change. Species with specific environmental needs or that have problems dispersing are likely to be most affected. The union is beginning similar work on other threats in collaboration with the Zoological Society of London.

In these tumultuous economic times, the emotional force of extinction is nothing to sniff at.

This week, the union announced a new Global Mediterranean Action Network to help coordinate research on various Mediterranean-like biomes (including California and the Cape of South Africa). And IUCN president, Valli Moosa, was set to announce his vision for how the extraterritorial ocean should be managed so that the ecosystems of the high seas do not remain a conservation-free zone. Meanwhile, the IUCN's various programmes are working on issues ranging from making hotels more environmentally friendly to researching what an effective 'payments for environmental services' legal regime would look like.

Still, the heart of the organization is the Red List. Whatever its flaws, most people agree that the list is an irreplaceable indicator of global environmental health, using a metric that feels intuitive to most of us: how many extinctions have we caused in the past four years? It is no surprise that the drafters of the Millennium Development Goals chose the Red List to be an indicator of progress towards reducing biodiversity loss.

Of course, the number of species explicitly studied and measured is dwarfed by the number of species yet to be discovered. To address this, the IUCN is beginning to use a sampling method to estimate the state of play in less-well-studied groups of organisms, such as invertebrates, taking its mammal survey as a calibration point.

The IUCN deserves credit for continuing to invest in the list, even though it clearly understands that conserving biodiversity requires much more than the list alone. Yes, ecosystems are more than just the sum of their parts — but there may be no more visceral way to convince people that conservation is worthwhile than to point to a species that has nearly died out due to human fumbling. The fishing cat (Prionailurus viverrinus) of southeast Asia has almost vanished. If reading that causes a pang, good. In these tumultuous economic times, when people are still trying to work out how to value 'ecosystem services', and when a full understanding of ecosystems is still decades away, the emotional force of extinction is nothing to sniff at.