Half of World’s Coral Species Face Extinction as Oceans Warm

Marine biologist David Obura, lead author of the assessment, described the findings as a stark warning of accelerating threats to global reefs. He noted that the data, which captures figures up to 2020, fails to account for the catastrophic 2023–2025 bleaching event. During that period, NOAA reported that 84% of the world’s reef area suffered heat stress, triggering massive mortality.

With projections of a severe El Niño cycle threatening to break further temperature records, researchers fear the proportion of at-risk species could soon exceed 50%. Human-caused climate change remains the primary driver, impacting 90% of the most vulnerable species. While the outlook appears grim, marine ecologist Françoise Cabada-Blanco emphasized that every fraction of a degree in averted warming provides a lifeline. The consensus among scientists is that the collapse of these ecosystems would jeopardize not only marine biodiversity but also the food security and coastal protection for millions of people worldwide.