Membership gives California a platform to help shape international environmental policy and share knowledge.
Gov. Gavin Newsom announced Thursday that California has been accepted as a member of the International Union for Conservation of Nature, becoming one of the first and largest subnational governments in the United States to join the global environmental organization.
The IUCN is the world’s largest and most diverse environmental network, uniting governments, NGOs and scientific institutions to develop conservation standards, protect ecosystems and promote the sustainable use of natural resources. Its work includes maintaining the Red List of Threatened Species and the Green List of Protected and Conserved Areas.
California’s membership follows the state’s announcement in October 2025, alongside Massachusetts, of its intent to join. Officials say the move will allow California to collaborate more directly with national governments and other partners on issues including biodiversity protection and climate-related challenges.
“California makes history by becoming one of the first subnational governments, and the largest from the United States, to join the IUCN,” Newsom’s office said in a statement.
Membership gives California a platform to help shape international environmental policy and share knowledge with a network that now includes dozens of regions and states worldwide. State officials have highlighted California’s existing efforts in marine protected areas, which recently received an IUCN Green List award.
The governor’s office described the development as a milestone that strengthens California’s global engagement on environmental issues. No immediate details were released on specific new projects or funding tied to the membership.
