The list is set upon precise criteria to evaluate the extinction risk of thousands of species and subspecies. These criteria are relevant to all species and all regions of the world.
The Red List is established upon strong scientific base, and is often recognised as the most authoritative guide to the status of biological diversity.
The Red List aim at conveying the urgency of conservation issues to the public and policy makers, as well as helping the international community to try to reduce species extinction.
Species are classified in 8 groups, set through criterias such as rate of decline, population size, area of geographic distribution, and degree of population and distribution fragmentation.