The IUCN has run its first global health check on coral reef ecosystems, and the result is grim. The assessment covers every warm, shallow reef on Earth, across 127 ecoregions and about 188,000 square kilometers. It found that 96% of these reef systems are already critically endangered and could collapse by 2075. The Great Barrier Reef, the Coral Triangle, the Mesoamerican reef and the Red Sea reefs all land in that category. All 17 Australian reef ecosystems rate critically endangered. Warming water is named the single most consistent driver of decline. A separate IUCN review two weeks earlier found 44% of 892 reef-building coral species threatened with extinction. There is one hopeful note. Most reefs are still alive and could recover if warming slows. It points to reefs that have survived repeated heatwaves, such as those off Bermuda and the northern Red Sea. Protect those first.
Source: IUCN Red List of Ecosystems, 22 October 2026
