Climate change could wipe out the world's richest ocean wilderness by the end of the century without drastic cuts in greenhouse gas emissions, environmental group WWF said Wednesday.

Rising water temperatures, sea levels and acidity are threatening to destroy the vast region of Southeast Asia known as the Coral Triangle, labelled the ocean's answer to the Amazon rainforest, the WWF said in a new report.

Collapse of the reefs would send food production in the region plummeting by 80 percent and imperil the livelihoods of over 100 million people.

With too little action on climate change, "you get a world in which you have perhaps tens of millions of people homeless by the inundation of coastlines through rapid sea level rises," report lead author Ove Hoegh-Guldberg said.

"You see the erosion of food security and you see a world by the end of this century which is, I think, pretty much a nightmare."