The History of IUCN Red List of Threatened Species

A quiver tree watches the sun set in the Namib desert.
A lone quiver tree watches the sun set in the Namib desert. Credit: Johann van Heerden/Getty Images.

Founded in 1948, the International Union for Conversation of Nature (IUCN) is the world's first global environmental organization dedicated to preserving the natural world upon which we all depend.

The IUCN's groundbreaking work has led to the creation of laws limiting the use of pesticides, international treaties to protect endangered species and the widespread use of environmental impact statements.

The IUCN Red List of Threatened Species, first published in 1964, has become the leading source of information about threatened and endangered species, and the IUCN continues to be among the most influential environmental organizations in the world. 

The Global Influence of the IUCN

Unlike other environmental organizations, IUCN members are governments and non-governmental organizations (NGOs), not individual citizens. The IUCN, which has observer status at the UN, focuses on educating the international community about threats to ecosystems around the world and organizing multi-state action on sustainable development.

With over 1,300 resolutions issued since its founding, the IUCN has played a key role in drafting the Convention of International Trade in Endangered Species (CITES) and the Convention on Biological Diversity, and in the establishment of the Intergovernmental Panel for Climate Change (IPCC). It also convinced the United Nations to grant consultative status to NGOs, which has been important in increasing the role of environmental organizations at the UN. 

IUCN Timeline


Governments and environmental organizations agree to found the IUCN in Fontainebleau, France, spurred on by members of the recently founded United Nations Educational, Scientific and Cultural Organization (UNESCO) and its Director General, Julian Huxley.


After over 10 years of relying on aid from UNESCO funding and other sources, the IUCN establishes the World Wildlife Fund (now the World Wide Fund for Nature) for fundraising purposes. The two organizations work closely together until they separated in 1985 so that the WWF could have more direct control over its own programs.


The IUCN publishes the Red List of Threatened Species. The number of species examined expands over time to become the most comprehensive database on global extinction risk for plants, animals, and fungi. Its original criteria have been adapted as well to more finely specify the level of threats to species.


The IUCN drafts and promotes the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), one of the first international agreements meant to protect endangered species. Under its auspices, agreements are in place to prevent the sale of ivory, shark fins, rhinoceros horns, manta rays, and pangolins.


The IUCN's role is essential in the United Nations General Assembly's adoption of the World Charter for Nature, despite the sole opposition of the United States. The Charter calls for the protection of nature during warfare, the conservation of unique natural areas, the maintenance of current population levels of all life forms, and the general respect for the essential processes of nature.


The IUCN plays a fundamental role in the creation of the Convention on Biological Diversity, adopted at the United Nations Conference on Environment and Development, better known as the “Earth Summit” in Rio de Janeiro. The Convention shifts international conservation focuses to the sustainability of ecosystems rather than the conservation of individual species.

The Red List of Threatened Species

Begun in 1964, the IUCN Red List is the most comprehensive list of threatened species consulted by, cited by, and written by scientists around the world. As of 2021, the Red List contains peer-reviewed assessments of over 134,400 species, categorizing them by how endangered they are. Over one-quarter (37,400) of those species are threatened with extinction. Often called the Barometer of Life, the Red List measures the pressure placed on both individual species and ecosystems more generally. The data in the list is used to track progress (or lack thereof) in meeting the targets of CITES, the Convention on Biological Diversity, and the United Nations Sustainable Development Goals.

The IUCN asserts that the “environmental wisdom of indigenous peoples and ancient cultures should be recognized" for the vital role they play in the protection of ecosystems. While they are less than 5% of the world's population, indigenous people live among 80% of the world's biodiversity. For example, the San peoples of southern Africa, among the oldest cultures, carry their arrows within the tubular branches of quiver trees. Quiver trees also provide shelter to social weaver birds and nectar to birds and baboons. Yet two species of quiver trees, Aloidendron ramosissimum, and Aloidendron pillansii, are identified in the IUCN Red List as vulnerable or decreasing. The same could be said of the San way of life.

Also on the Red List is the yellow-cedar, Xanthocyparis nootkatensis, whose dieback is widespread in southeast Alaska. The Tlingit, the “community of people...with the longest cultural history of using yellow-cedar,” weave baskets, blankets, and clothing from its fibrous inner bark. The tree is essential to Tlingit culture: “If we don't have our trees...we can't be who we are,” says Tlingit elder Kasyyahgei/Kasake/Ernestine Hanlon-Abel. The Tlingit converse with the yellow-cedars — the “Tree People,” they call them, “all such different personalities,” but the Tlingit tongue itself is endangered, threatening their ability to communicate with their ancestors. The preservation of the yellow-cedar and Tlingit culture go hand in hand.

Witches cauldron, Sarcosoma globosum, among moss.
Witches cauldron, Sarcosoma globosum, among moss. Credit: Henrik_L/Getty Images.

Reading the Red list is daunting. The most common images of threatened and endangered species are the “charismatic species,” the species we know by name, the ones we recognize from the media: the condor and koala, the polar bear, and panda. However, most of the 37,400 threatened species on the Red List, let alone the 97,000 other species of less threatened status, are known only by specialists. Yet all of them are essential to the ecosystems they inhabit. Few people other than biologists know that Sargassum albemarlense or Gracilaria skottsbergii are algae of the Galapagos Islands. Sea urchins and sea turtles know them and eat them, but sea urchins and sea turtles cannot protect them. One will rarely find mention of Riccia atlantica or Bazzania azorica, liverworts found on remote Atlantic islands, outside of journals with titles like The Bryologist or Cryptogamie, Bryologie. Liverworts have never appeared in fundraising appeals with doe-eyed faces to open our wallets and hearts. Some species are as unappealing as the witches' cauldron, Sarcosoma globosum, an ugly fungus vital to decomposing leaf litter, with a blackish-brown skin and a bluish gelatinous pulp — and no human uses. And some threatened species are indeed threats to humans, like Dioon sonorense, a cycad of the Chihuahuan Desert, all parts poisonous.

Who but those with an appreciation of the balance of nature will want to protect these obscure and overlooked species? Who beyond the contributors to the IUCN Red list is there to defend the bold-striped cool-skink or the hog-nosed skunk? Only 180 individuals of the humble barn fern, only 122 of the toothed tongue-fern, only 40 of the Ascension Island parsley fern, remain in the wild. Who will be there to record when the last of them dies?

View Article Sources
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  2. "Background & History." International Union for Conservation of Nature Red List Of Threatened Species.

  3. "How the Red List Is Used." International Union for Conservation of Nature Red List Of Threatened Species.

  4. "IUCN 2019: International Union for Conservation of Nature Annual Report 2019." International Union for Conservation of Nature.

  5. Values of Indigenous Peoples Can Be a Key Component of Climate Resilience.” United Nations Climate Change.

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  7. Lambdon, P.W. and Ellick, S. "Elaphoglossum dimorphum." International Union for Conservation of Nature Red List of Threatened Species, 2016., doi:10.2305/IUCN.UK.2016-1.RLTS.T44727A67372642.en

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