Compilation and reporting of the Red List Index at the global level is conducted by the International Union for Conservation of Nature (IUCN) and BirdLife International, on behalf of the Red List Partnership.
The Red List Index is based on categorisations of species on the IUCN Red List of Threatened Species (http://www.iucnredlist.org/), defined following IUCN (2012a).
January 2022
The Red List Index measures change in aggregate extinction risk across groups of species. It is based on genuine changes in the number of species in each category of extinction risk on The IUCN Red List of Threatened Species (www.iucnredlist.org) is expressed as changes in an index ranging from 0 to 1.
The Red List Index value ranges from 1 (all species are categorized as ‘Least Concern') to 0 (all species are categorized as ‘Extinct'), and so indicates how far the set of species has moved overall towards extinction.
The Red List Index for a particular country or region is an index of the aggregate extinction risk for species within the country or region relative to its potential contribution to global species extinction risk (within the taxonomic groups included), measured on a scale of 0 to 1, where 1 is the maximum contribution that the country or region can make to global species survival, equating to all species being classified as Least Concern on the IUCN Red List, and 0 is the minimum contribution that the country or region can make to global species survival, equating to all species in the country or region having gone extinct.
The Index is of particular relevance as indicator towards the Sustainable Development Goals (SDGs) and more specifically the target 15.5 - "take urgent and significant action to reduce the degradation of natural habitats, halt the loss of biodiversity and, by 2020, protect and prevent the extinction of threatened species ".
January 2022
The Red List Index measures change in aggregate extinction risk across groups of species. It is based on genuine changes in the number of species in each category of extinction risk on The IUCN Red List of Threatened Species (www.iucnredlist.org) is expressed as changes in an index ranging from 0 to 1.
The Red List Index value ranges from 1 (all species are categorized as ‘Least Concern') to 0 (all species are categorized as ‘Extinct'), and so indicates how far the set of species has moved overall towards extinction.
The Red List Index for a particular country or region is an index of the aggregate extinction risk for species within the country or region relative to its potential contribution to global species extinction risk (within the taxonomic groups included), measured on a scale of 0 to 1, where 1 is the maximum contribution that the country or region can make to global species survival, equating to all species being classified as Least Concern on the IUCN Red List, and 0 is the minimum contribution that the country or region can make to global species survival, equating to all species in the country or region having gone extinct.
The Index is of particular relevance as indicator towards the Sustainable Development Goals (SDGs) and more specifically the target 15.5 - "take urgent and significant action to reduce the degradation of natural habitats, halt the loss of biodiversity and, by 2020, protect and prevent the extinction of threatened species ".