Corals are seen at the Great Barrier Reef in this January 2002 handout photo. Rising carbon dioxide levels in the world's oceans due to climate change, combined with rising sea temperatures, could accelerate coral bleaching, destroying some reefs before 2050, says a new Australian study. [China Daily via Agencies]

The study found that coralline algae, which glue the reef together and help coral larvae settle successfully, were highly sensitive to increased CO2.

"These may die on reefs such as those in the southern Great Barrier Reef before year 2050," study leader Ken Anthony said in a statement released on Tuesday.

Some coral species were able to cope with higher levels of ocean acidification by enhancing their rates of photosynthesis, but if CO2 levels became too high "the coral-algal system crashes and the corals die", said the study.

"The implications of this finding are massive as it means that our current bleaching models, which are based on temperature only, severely underestimate the amount of coral bleaching we will see in the future," said Anthony.

"These results highlight the urgency of reducing CO2 emissions globally. Without political will and commitment to abatement, entire reef systems such as the Great Barrier Reef will be severely threatened in coming decades."

(Shanghai Daily via Agencies October 29, 2008)