On April 15, 2024, NOAA (in partnership with the International Coral Reef Initiative) confirmed the world is in the midst of its 4th global coral bleaching event. From 1 January 2023 to 20 April 2025, bleaching-level heat stress has impacted 83.7% of the world’s coral reef area and mass coral bleaching has been documented in at least 83 countries and territories.
The ongoing global coral bleaching event is the biggest to date. The previous record was during the 3rd global coral bleaching event, which occurred from 2014-2017, when 68.2% of the world’s reef area experienced bleaching-level heat stress. The 1st and 2nd global coral bleaching events occurred in 1998 and 2010, respectively.