The IUCN Green List of Species: An Optimistic New Vision for Conservation

Abstract

The International Union for Conservation of Nature's Red List of Threatened Species has become the global standard for assessing the risk of extinction each species on earth faces. However, conservation also needs an optimistic vision of species conservation that presents a road map on how to achieve recovery, and the IUCN is creating a new set of metrics to do just that. These new metrics, known collectively as the "Green List of Species," will be incorporated into the Red List in the coming years (note that this is a third, separate initiatve from the Green Lists of Protected Areas and of Ecosystems). Like the Red List, the Green List of Species will rely on expert opinion informed by the latest available data, but will incorporate a more formal structured expert elicitation approach. The Green List of Species will evaluate species' recovery status in terms of function (is the species fulfilling its role, or functionally extinct?) and geographic distribution relative to its historical range. It will also assess how conservation actions have contributed to recovery status using counterfactual approaches. However, these metrics must be refined before rollout, considering the challenges presented by species with varying life histories and qualities of data. Here, we present the working Green List of Species assessment framework and invite feedback.