Inevitable global coral reef decline under climate change-induced thermal stresses

Coral reefs, among the most biodiverse ecosystems on Earth, face an existential threat from the increasing frequency and intensity of coral bleaching events driven by global warming. While much of the existing research examines bleaching as an isolated phenomenon, the critical threshold linking bleaching rates to long-term reef degradation remains poorly understood. Here we identified pivotal factors influencing coral bleaching rates at a global scale, leveraging a data-driven model integrating historical field observations with climate simulations across multiple emission scenarios. Our findings reveal a critical bleaching threshold of 7.9% annually, beyond which coral reef ecosystems would undergo significant degradation. Alarmingly, even under the most optimistic mitigation pathways, substantial degradation is projected across all major tropical marine regions by the end of the century. This study highlights the urgent need for bold and effective global policies to safeguard coral reef ecosystems and ensure their sustainability under an increasingly warming climate. Coral reef ecosystems will undergo significant degradation if annual bleaching rate exceeds 7.9%, according to combined historical field observations and future climate simulations.