1. Increase temperature of the oceans: This causes the bleaching of corals. Bleaching of coral reefs is the loss of pigments and microscopic plant cell from coral tissues. This result in the whitening of the coral reefs.
2. Rise in sea level: Sea levels are rising due to thermal expansion of the ocean and the melting of land ice. This may eventually lead to flooding of the coastal land.
3. Change in world climatic patterns: The climatic patterns in most parts of the world have changed. It is becoming hard to forecast the weather accurately. Rain no longer fall when expected. Sometimes the rains are heavier than expected, leading to flooding, other times, the rain are far less than expected, leading to drought. The extent of the earth surface under desert condition is also increasing.
4.
Acidification of the oceans: The world’s oceans soak up
much of the carbon dioxide produced by living organisms either in the form of
dissolved gas, or from the skeleton of tiny marine creature that fall to the
bottom to become chalk or limestone.
The carbon dioxide
dissolved in the water and forms a weak carbonic acid, thereby lowering the pH
of the ocean water. Increased acidity and temperature of ocean waters
eventually lead to the bleaching and death of coral reefs.