The World Conservation Union (IUCN), widely considered to be the most objective and authoritative system for classifying species in terms of the risk of extinction, lists 3071 species (1528 animals, 1541 plants, 2 fungi) of the world as being critically endangered in their 2006 Red List. Additionally 254 subspecies or varieties are considered critically endangered, and 30 subpopulations or stocks have been assessed with a critical risk of (local) extinction.