Ningaloo Reef in Western Australia is in the news this week for the wrong reason. Stories about Ningaloo usually celebrate spectacular phenomena like mass coral spawning or gathering whale sharks. This time it’s about a spectacle none of us want to hear about: coral bleaching.

This news is more than usually disheartening to me because Ningaloo’s corals have held out against bleaching longer than almost any other reefs in the world, leading some to think this might be a climate-proof coral haven. Strife for Ningaloo follows mass bleaching in January in another supposed climate resilient spot – Raja Ampat in West Papua. Both have been broiled by a vast blob of hot water straddling south-east Asia’s Coral Triangle, home to the most diverse marine life in the world.

A few years ago, a team of Australian scientists mapped the distribution of every recorded coral bleaching event to date. They hoped to find patterns that would guide them to bleaching resistant regions where coral conservation efforts might be directed. Instead, as time went on, they found repeated bleaching events ate up more and more space on the world map. The uncomfortable truth is that no reefs will be spared coral bleaching, because the global ocean is warming fast.

In the first two months of this year, ocean temperatures have come close to the record levels set last year. I must confess, I feel conflicted about warming seas. What is bad for corals is good for us. Water is an excellent thermal store. The sea has absorbed an estimated 93% of the extra heat added to the planet because of our greenhouse gas emissions. Sea surface temperature has risen by a bit over 1^oC as a result. If that heat had stayed in the atmosphere, the air would be 36^oC hotter than pre-industrial times and those of us left would be trapped indoors by Death Valley temperatures. The ocean is our planetary air conditioner and long may it remain so!