Mass coral bleaching strikes the Great Barrier Reef

In the summer of 2016, a marine heatwave driven by a strong El Nino and global warming caused the worst mass bleaching ever seen on Australia's Great Barrier Reef, the largest coral reef system in the world. Corals expel the algae that give them colour and food when waters are too hot, and aerial surveys showed that about 90 per cent of reefs were affected. About 30 per cent of the shallow-water corals died, and in the northern third of the reef two thirds. More bleaching followed in 2017, 2020, 2022 and 2024. Scientists say that without cuts in emissions, the world's reefs could largely disappear in this century.

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