Ongoing Global Coral Bleaching Crisis
- Dogeon Lim
- May 7
- 2 min read
May 7, 2025
Dogeon Lim
Coral bleaching is a term that was recognized in 1998 after this phenomenon became widely known which describes stressed coral that changes white due to harsh changes in temperature, pH level, etc.
The world’s coral reefs are undergoing the bleaching event that began in 2023 and became the most extensive bleaching event ever recorded.
The ongoing global coral bleaching event (GCBE4), which began in January, 2023. Coral bleaching events can cause widespread coral death, disturbing reef ecosystems, threatening marine biodiversity, and affecting human communities that rely on reefs for food, tourism, and coastal protection.
According to the US National Oceanic and Atmospheric Administration (NOAA), “About 83.7% of the world’s 83 coral reef territories were experiencing high levels of heat stress, triggering widespread bleaching and increasing risk of mortality.”
Typically the affected areas were Australia's Great Barrier Reef which is the world’s largest coral reef system, Florida, the Caribbean, Brazil, the eastern Tropical Pacific, and large areas of the South Pacific etc. NOAA said “Widespread bleaching has also been found from the Indian Ocean basin.
According to the World Meteorological Organization (WMO), for the past 8 years has set the new record for ocean heat content. The rate of ocean warming over the past two decades is more than twice that of 1960-2005.
In Particular, 2024 was the highest ocean heat level during the whole WMO’s 65 year observational record. Last year, from January to June the sea surface temperature reached its highest record levels. In the second half of 2024, the temperature was the second highest ever recorded for that period, after 2023.
Coral reefs are mostly important ecosystems that exist in more than 100 countries and support about 25% of marine species. They are sometimes called “rainforests of the sea” due to their ability to act as carbon sinks by absorbing the excess carbon dioxide in the water.
Unfortunately, they are disappearing at a rapid pace. According to the recent report by Global Coral Reef Monitoring Network (GCRMN), the world has already lost about 14% of corals reefs since 2009.
