Increased frequency of severe weather events
- More intense cyclones can destroy and weaken the reef structure.
- More extreme rainfall events will send more freshwater and sediment further out from the coast and on to the Reef.
Rising sea temperature
- Greater risk of heat stress and mass coral bleaching.
- Changes in the ocean's chemistry can decrease the capacity of corals to build skeletons, decreasing their capacity to create habitat for the Reef's marine life.
- Since the late 18th century, the oceans have absorbed about 30% of the additional carbon dioxide that human activities have injected into the atmosphere. This extra CO2 in the oceans has changed their chemistry, a process known as ocean acidification, with the pH of oceans decreasing.
Rising sea levels
- Higher seas can impact many areas including coastal erosion, the size of storm surges and the area available for shallow water marine organisms.
- Small changes in sea levels will mean land inundation which will cause significant changes in tidal habitats such as mangroves and saltwater intruding into low-lying freshwater habitats.
Facing these and other natural and human-induced pressures, coral reefs will be more vulnerable to coral bleaching, disease, crown-of-thorns starfish and tropical cyclones.