Emergent increase in coral thermal tolerance reduces mass bleaching under climate change

Recurrent mass bleaching events threaten the future of coral reefs. This study reveals an emergent increase in the thermal tolerance of coral assemblages at a rate of 0.1 °C/decade for a remote Pacific coral reef system in Palau. This increase led to less severe bleaching impacts than predicted, suggesting adaptation, acclimatisation, or community structure shifts. Future climate projections show that if this rate of thermal tolerance increase continues, substantial reductions in bleaching are possible, potentially mitigating high-frequency bleaching under low-to-middle emissions scenarios. However, under high emissions scenarios, bleaching can only be delayed. The results indicate potential ecological resilience but emphasize the crucial need for carbon emission reductions.

Liam Lachs, Simon D. Donner, Peter J. Mumby, John C. Bythell, Adriana Humanes, Holly K. East, James R. Guest