Coral Reefs: A Race Against Climate Change

Coral reefs are disappearing faster than rainforests. These underwater cities cover less

than 0.2% of our ocean but house 30% of all marine species. Here's what's killing

them. When ocean temperatures rise just half a degree above 28°C, corals literally

kick out the colorful algae living inside them. It's like evicting your roommate who

pays 90% of the rent. Without these algae, corals lose their food source and

turn ghost white. This is coral bleaching. The 2016 bleaching event hit 90% of Australia's Great

Barrier Reef. Scientists estimate we've already lost 19% of all reefs worldwide.

But there's hope. Some corals in the Persian Gulf survive temperatures above 34°C.