Global average sea surface temperatures have risen at unprecedented rates for the past three decades, with far-reaching consequences for coral reefs. Today, the majority of coral reefs are surviving at their upper thermal limit and an increase in just one degree Celsius lasting longer than a few weeks can lead to coral bleaching and death. With projections of ocean warming expected to continue to rise by as much as 1.5 degrees Celsius in this century, scientists are in a race against time to find new solutions to sustain reefs.