Australia's Great Barrier Reef is proving more resilient than thought to sudden spikes in sea temperatures, a study published today shows, offering a glimmer of hope for the future of reefs globally in a world facing escalating risks from climate change.

Coral reefs house about a quarter of all marine life. They are essential for fisheries, tourism and protecting coastlines from waves and storms. But corals are particularly sensitive to sharp spikes in sea temperatures. Prolonged exposure turns them a ghostly white. This is called bleaching and if the marine heatwave lasts several weeks or more, the corals can die.