Coral reefs are probably the most complex ecosystems on the planet, home to hundreds of species. They protect and support the lives of millions of people around the tropical zones, and are a font of recreation. The damage being caused to reefs by warming seas is one of the most serious effects of global warming.

Rising sea temperature coupled with the strong El Niño of 1998 was devastating to much of the world’s coral reefs. Temperatures beyond norms cause coral to expel the microscopic symbionts, zooxanthellae that also give them color. If this bleaching continues for days to weeks, the coral dies and algae takes over the reefs, changing the ecosystem. With the sea level rising, coral, which thrives at and near the sea surface, is not expected to be able to keep pace with this rapid increase in water depth.

In addition, seas are dissolving more and more carbon dioxide (CO2). Even though this adds more carbon, a raw material for coral making calcium carbonate reefs, it also acidifies the water, actually inhibiting the growth of coral by corroding its limestone structures as well as seashells.

Coupled with damage from human activities and development, this growing danger has lead some scientists to predict the end of reefs across much of the ocean. Living coral may be reduced by 95 percent on the Great Barrier Reef. Loss of coral reefs would translate into huge economic losses in coastal regions dependant on them, as well as an ecological catastrophe, being a home to a rich diversity of marine life such as reef fish, turtles, sharks, lobsters and sponges.