New map triples the coral reefs that could survive warming
A study presented at the Our Ocean conference identified more than 165,000 square kilometers of climate-resilient coral reefs, three times the 2018 estimate.
- The study identified more than 165,922 square kilometers of climate-resilient coral reefs across 71 countries.
- It found three times as many climate refugia as the benchmark 50 Reefs study from 2018.
- More than half of those reefs sit in just five countries: the Bahamas, Cuba, Australia, Indonesia and the Philippines.
- The model was trained on decades of coral observations and produces a map 10,000 times more detailed than earlier ones.
A team of scientists presented a study in June 2026 at the Our Ocean conference in Kenya that maps coral reefs capable of surviving ocean warming through 2050. The research identified more than 165,922 square kilometers of climate-resilient reefs across 71 countries, three times the area estimated by the influential 50 Reefs study in 2018. The findings matter because they shift the baseline for conservation: where the field once spoke of a few dozen priority sites, there is now a considerably wider network of possible refugia.
Coral reefs are among the ecosystems most severely affected by climate change. Heat waves trigger bleaching, when corals expel their symbiotic algae and, if the stress persists, die. The 2018 study 50 Reefs was an attempt to prioritize the locations with the best chance of survival, but it relied on coarser data resolution. The new paper, titled Machine-learning and prioritization models reveal climate refugia for coral reefs into 2050, uses machine-learning models trained on decades of field observations of corals, which produced a map roughly 10,000 times more detailed than its predecessors.
What does it actually mean for a reef to be resilient?
Resilience here is not a single trait but a set of conditions. The researchers distinguish several types of refugia: places in naturally cooler parts of the ocean that avoid the worst heat waves, places populated by heat-adapted corals, and places with the capacity for rapid ecological recovery after a disturbance. The model combines these factors to estimate where reefs have the best odds of persisting under the climate scenarios projected for mid-century.
The concentration of the findings is striking. More than half of the resilient reefs identified sit in just five countries: the Bahamas, Cuba, Australia, Indonesia and the Philippines. That means the decisions of a handful of governments could disproportionately shape the fate of global coral ecosystems. According to the study, a significant share of the mapped refugia is currently not under formal protection, so the authors propose folding those reefs into networks of marine protected areas.
How far do the conclusions reach?
It is worth being precise about what the study shows and what it does not. This is a modeling paper: it estimates the probability of survival based on historical data and assumptions about future warming, and it does not guarantee that any specific reef will survive. The results depend on how closely the underlying climate scenarios play out; warming more aggressive than assumed would shrink the space available for refugia. Resilience to heat waves also does not shield reefs from other pressures such as pollution, overfishing and ocean acidification.
What the paper does clearly offer is a prioritization tool, a map detailed enough to be usable for conservation planning at the local level. Will that map actually reshape the layout of marine protected areas, or will it remain another well-documented proposal waiting on political will?
