DeCarlo T. M. auteur aut IRD Harrison H. B. auteur aut IRD Gajdzik L. auteur aut IRD Alaguarda D. auteur aut IRD Rodolfo-Metalpa Riccardo auteur aut IRD D'Olivo J. auteur aut IRD Liu G. auteur aut IRD Patalwala D. auteur aut IRD McCulloch M. T. auteur aut IRD text journalArticle eng text/pdf reformatted digital access Reef-building corals typically live close to the upper limits of their thermal tolerance and even small increases in summer water temperatures can lead to bleaching and mortality. Projections of coral reef futures based on forecasts of ocean temperatures indicate that by the end of this century, corals will experience their current thermal thresholds annually, which would lead to the widespread devastation of coral reef ecosystems. Here, we use skeletal cores of long-lived Porites corals collected from 14 reefs across the northern Great Barrier Reef, the Coral Sea, and New Caledonia to evaluate changes in their sensitivity to heat stress since 1815. High-density 'stress bands'-indicative of past bleaching-first appear during a strong pre-industrial El Nino event in 1877 but become significantly more frequent in the late twentieth and early twenty-first centuries in accordance with rising temperatures from anthropogenic global warming. However, the proportion of cores with stress bands declines following successive bleaching events in the twenty-first century despite increasing exposure to heat stress. Our findings demonstrate an increase in the thermal tolerance of reef-building corals and offer a glimmer of hope that at least some coral species can acclimatize fast enough to keep pace with global warming. specialized coral reefs acclimatization climate change ocean warming coral bleaching AUSTRALIE PACIFIQUE MER DE CORAIL NOUVELLE CALEDONIE NOUMEA 036 034 032 021 286 1898 20190235 [7 ] 2019 0962-8452 https://www.documentation.ird.fr/hor/fdi:010075694 10.1098/rspb.2019.0235 0962-8452 [F B010075694] https://www.documentation.ird.fr/hor/fdi:010075694 https://horizon.documentation.ird.fr/exl-doc/pleins_textes/divers19-05/010075694.pdf IRD - Base Horizon / Pleins textes 2019-06-04 2025-10-13 fdi:010075694 fre