IUCN classifies 96% of assessed coral reef ecosystems as Critically Endangered, warning of collapse risk by 2075

Key facts

• The first global coral reef assessment under the IUCN Red List of Ecosystems, released on October 22, 2026 at CBD COP17 in Yerevan, Armenia, classified 96% of assessed shallow-water coral reef ecosystems as Critically Endangered, indicating risk of collapse by 2075.
• The assessment covered reefs in more than 80 countries and territories, spanning 127 tropical and subtropical ecoregions and 188,362 square kilometres of coral reefs, including the Great Barrier Reef, the Coral Triangle, the Mesoamerican Barrier Reef System and Red Sea reefs.
• Heat stress from human-induced climate change, causing mass bleaching through ocean warming and marine heatwaves, is the single most dominant threat; overfishing of key species like parrotfish and grouper threatens 63% of reef ecosystems.
• The assessment uses the IPCC's middle-of-the-road scenario projecting 2.7°C warming by the end of the century. Based only on observed changes over the past 50 years and excluding future climate projections, 24% of assessed ecosystems would be Critically Endangered.
• Coral reefs support 25% of all marine species, and the Western Galápagos Islands ecosystem is already classified as Collapsed since the 1982-83 El Niño event.
• IUCN Director General Grethel Aguilar and assessment scientific lead Mishal Gudka emphasized that reefs are not yet lost and require decisive emissions reductions, stronger protection, and sustained investment.