The International Union for Conservation of Nature (IUCN) is a unique international institution and the world's largest and oldest global environmental network, founded on October 5, 1948, in Fontainebleau, France. It was initially called the International Union for the Protection of Nature (IUPN), created to address the problem of safeguarding the natural world and promoting the sustainable use of natural resources after World War II. The IUCN's mission is to "influence, encourage and assist societies throughout the world to conserve nature and to ensure that any use of natural resources is equitable and ecologically sustainable".
The core mechanism of the IUCN is its democratic membership structure, which unites over 1,400 governmental and civil society organizations, along with the voluntary expertise of approximately 17,000 scientists and experts across six commissions. The organization is best known for compiling and publishing the IUCN Red List of Threatened Species, established in 1964, which is the global authority on the conservation status of species. The Red List classifies species into nine categories, such as Critically Endangered (CR), Endangered (EN), and Vulnerable (VU), based on five quantitative criteria like population decline rate and geographic range.
The IUCN connects directly to major international agreements, providing advice and data to conventions like the Convention on Biological Diversity (CBD), the Convention on International Trade in Endangered Species (CITES), and the Framework Convention on Climate Change. It also holds official United Nations Observer Status, ensuring nature conservation has a voice in international governance. The organization has evolved over time; in 1994, its mission was redrafted to integrate social aspects of conservation, including the equitable use of natural resources, and it has recently championed the concept of Nature-based Solutions since 2009.