The fourth global bleaching event is confirmed
NOAA Coral Reef Watch and the International Coral Reef Initiative jointly confirmed that the thermal stress recorded through 2023 and into 2024 constituted a fourth global bleaching event, with bleaching-level heat stress recorded across reef areas in the Atlantic, Pacific and Indian Oceans. Subsequent updates reported the affected share of global reef area rising through the following year to a level exceeding any previous event. The declaration is a statement about satellite-measured thermal stress across ocean basins, not a survey of mortality, and the two should not be read as the same measurement.
Observed — measured or witnessed, with the observation cited.
Subjects
- NOAA Coral Reef Watch · research programme · United States · not located
- International Coral Reef Initiative · organisation · not located
- Coral bleaching · ecological phenomenon · Global tropical reefs · not located
- Degree Heating Weeks (DHW) · physical quantity · not located
Evidence
Partly verified — Core facts are sourced; some optional detail is deliberately absent.
Confirmation of the fourth global coral bleaching event
NOAA Coral Reef Watch and ICRI confirmed in April 2024 that bleaching-level heat stress across the Atlantic, Pacific and Indian Ocean basins constituted a fourth global bleaching event, with the affected share of world reef area subsequently reported as rising above that of any previous event. V55 verification basis: NOT retrieved. The April 2024 confirmation is stated from the producing model's knowledge; no percentage of affected reef area is quoted here, and the state of the event as of August 2026 is not established — see EVT_GLOBAL_EVENT_STATE_2026.
International Coral Reef Initiative with NOAA Coral Reef Watch · 2024-04, with subsequent updates · Partly verified
ICRI and NOAA Coral Reef Watch joint announcement and subsequent updates (icriforum.org). NOT RETRIEVED: the domain is blocked by this session's egress proxy.
Recorded on NOAA Coral Reef Watch
- The International Coral Reef Initiative is formed
- The first global mass bleaching event
- A published projection that reefs would bleach faster than they could recover
- The third global bleaching event
- Mass bleaching on the Great Barrier Reef
- A second consecutive year of mass bleaching on the Great Barrier Reef
- The interval between severe bleaching events is measured, and it has collapsed
- The fourth global bleaching event is confirmed
Related
Related because they share a subject in the Atlas — never because the text looks similar.
- The interval between severe bleaching events is measured, and it has collapsed · 2018-01
- A second consecutive year of mass bleaching on the Great Barrier Reef · 2017
- Mass bleaching on the Great Barrier Reef · 2016-03 to 2016-04
- The third global bleaching event · 2014–2017
- A published projection that reefs would bleach faster than they could recover · 1999
- The first global mass bleaching event · 1998
- The International Coral Reef Initiative is formed · 1994 (announced; first workshop 1995)