A study by the University of Sydney has found that 25% of Australia’s coral islands, which are home to an estimated 65 million people, face a high to very high risk of being wiped out by climate change.

The study, published in the journal Science of the Total Environment, identified that all 56 investigated Australian coral islands are exposed to some degree of climate risk, with three small, unvegetated coral islands in Western Australia being the most vulnerable.

The researchers used open-access ocean climate data and satellite imagery to build a risk system that could be applied globally to prioritize protection efforts for vulnerable coral islands.