IN THE SUMMER of 2016 everything changes. Portentous news should come by phone, or a knock on the door, maybe a letter dropping onto a mat. But in this case, it is everywhere. Inescapable. The Great Barrier Reef is dying, some say dead. A wave of bleaching has swept across the coral. The reef is large – the size of Japan – and it takes months to confirm what scientists already suspect. This coral-bleaching event, caused by unusually warm waters, is the worst in history.

When the surveys are released, I delve into the details. The northern reef is the worst. More than 80 per cent of the coral around Lizard Island has died. The shock is visceral, like news of a car crash. I glance up at the framed photos next to my desk: a clown fish nestles in an anemone, and a violet nudibranch dances in blue. I’d taken the photos with my ancient underwater camera, a Nikonos III, on one of those long-ago dives. Those glorious reefs. Gone. In an instant.