Study Reveals Over Half of World’s Coral Reefs Suffered Bleaching During Third Global Event
A study published in Nature Communications reveals that 51% of the world’s coral reefs experienced moderate or worse bleaching between 2014 and 2017. This period, known as the 'Third Global Bleaching Event,' saw 15% of reefs suffer significant mortality. Experts warn that an even more severe 'Fourth Event' began in early 2023. Coral bleaching occurs when heat stress causes corals to eject symbiotic algae, leading to starvation. With global temperatures already exceeding 1.5°C on average between 2023-2025, the scientific consensus suggests most reefs may perish unless warming is drastically curtailed.
Key Points
- The 2014-2017 bleaching event was the most widespread and severe on record until the current 2023 event.
- Bleaching is a stress response where corals lose their color and primary food source (algae) due to rising sea temperatures.
- Ongoing warming threatens irreversible degradation of essential marine ecosystems that support biodiversity.
- The 1.5°C limit set by the 2015 Paris Agreement is a critical threshold for the survival of most coral reefs.
Exam Facts
- Study published in the journal Nature Communications.
- Third Global Bleaching Event occurred between 2014-2017.
- Global temperatures exceeded 1.5°C on average between 2023-2025 according to Copernicus data.
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