There are several causes of global warming that include ocean acidification and rising sea temperatures among others leading to many negative effects on coral reef.

First, coral bleaching, a term used to describe the expulsion of algae from coral cells due to which they become white. This occurs due to high temperatures. The 2016 coral bleaching event that was recorded on the Great Barrier Reef accounted for 30% of the entire reef.

Second, the ocean absorbs more CO2 which increases the amount of carbonic acid that enters the ocean, making it the cause of acidification. It is said among corals that acidities this high make it almost impossible to maintain their skeletons and calcify which results in lower growth rates and the increased dissolution of their skeletons.

Third, when the sea level increases, the corals sink deeper and deeper, so the sunlight that is needed for photosynthesis becomes less available, and so the corals have to work twice as hard to keep on living.

Also, as the ocean became warmer so hurricanes and typhoons were more and more common, which also caused damage and dramatic destruction to the coral reefs because of the climate change.

This along with the ocean temperature rising, increases the outbreak of coral diseases and pests, which, in turn, are the main contributors to the weakening of coral reefs. The result is the reduced growth of coral colonies.

Examples include the 2020 coral bleaching event at the Great Barrier Reef, 25% of the reef is affected; the coral cover has gone from 50% in the Caribbean in 1970 to the current 10%, and also, in the Maldives, 90% of coral cover has disappeared between 2010 and 2016.

In addition, the gradual loss of coral covers has been contributed by some local stressors such as pollution and overfishing alongside the above inspired by global evolutions. They may cause direct impoverishment in the poor populations dependent on them. The urgent need for the rescue of coral reefs and the fight against climate change is undeniably required.