Global Heating Drives Worst Mass Coral Bleaching Event on Record

The world's coral reefs are currently undergoing a global bleaching event due to unusually high ocean temperatures. This is the fourth such event on record and is expected to affect more reefs than any previous one. Bleaching occurs when corals become stressed, causing them to expel the symbiotic algae they need to survive. According to various reports, over 54% of the world's coral reef areas have experienced bleaching in the past year. The climate crisis is driving record-breaking ocean heat, leading to mass bleaching events in all of the world's oceans. Corals are invertebrates that live in colonies and secrete calcium carbonate to form protective structures. When corals experience significant heat stress, they can turn a ghostly white color and may die as a result. The U.S. National Oceanic and Atmospheric Administration has confirmed the fourth mass global bleaching event is underway. A global bleaching event is declared when at least 12% of corals in each of the main ocean basins (Pacific, Atlantic, and Indian) experience bleaching-level heat stress within a 12-month period. Some reports describe the sea temperatures as "off the charts."