Definitions of marine heatwaves currently depend on baseline temperatures (see D. Amaya et al. Nature 616, 29–32; 2023). But use of these baselines fails to capture the impact of marine heatwaves on marine organisms (A. Sen Gupta et al. Nature 617, 465; 2023). To better inform adaptation measures to ocean warming, we suggest using a definition that derives from the effects on marine ecosystems. Lessons could be drawn from human responses to heat.
Competing Interests
The authors declare no competing interests.
