Can the world's shallow coral reefs still be saved?

The International Union for Conservation of Nature says 96% of shallow coral reefs are now rated critically endangered, its highest threat level.

Heat drives that risk. The projection assumes warming of 2.7 degrees by the end of the century, above the original 1.5 degree goal.

The Global Coral Reef Monitoring Network warned recovery time is running out. Reefs once had decades between severe bleaching; often only five to six years remain now. Manuel González Rivero, lead author of that report at the Australian Institute of Marine Science, says This creates a downward spiral that becomes harder to reverse with each new bleaching event.

Still, IUCN director general Grethel Aguilar says It is not too late to give coral reefs a chance to recover, but this requires decisive action to fight climate change and halt ocean warming.