Global distribution of exposure category and SST variability level in the 1986–2019 climate and at 1.5 and 2.0°C of future global warming relative to pre-industrial levels.

Exposure categories are thermal refugia (probability of DHW events > 4°C-weeks less than 0.1 yr ‒1 ), intermediate (probability of DHW events > 4°C-weeks from 0.1–0.2 yr ‒1 ) and exposed (probability of DHW events > 4°C-weeks greater than 0.2 yr ‒1 ). Exposure categories are split by the level of SST variability (high = seasonal OR inter-annual variability > 0.7°C, low = seasonal AND inter-annual variability < 0.3°C, moderate = all others). The 12 coral reef regions are outlined in light blue. Bars indicate the percentage of 1 km reef pixels in each exposure category. The base map is made with Natural Earth.