Weather & Science

‘Unprecedented’ Ocean Heat Waves in 2023 Suggest Climate Tipping Point

Marine heat waves that year were unusually intense and lasted much longer than average, posing a threat to ecosystems, researchers say. 

Beached and dead coral around Lizard Island on the Great Barrier Reef near Cairns, Australia.

Photographer: David Gray/AFP/Getty Images

The world’s oceans experienced a staggering amount of warming in 2023, as vast marine heat waves affected 96% of their surface, breaking records for intensity, longevity and scale, according to a new study.

That could mark a turning point in the way the oceans behave, potentially signaling a tipping point after which average sea temperatures will be reset higher and some ecosystems may not recover, say the authors of the study, which was published Thursday in the journal Science.