After the publication of the Great Barrier Reef’s obituary, the public finally caught wind of what scientists and researchers had been sounding the alarm on for years: coral reefs are not dead yet but they could be soon. Unfortunately, while the obituary brought much care and condolence, it has done little in the way of action. And now we’re faced with only one solution for saving coral reefs around the globe: sticking to the Paris Climate Change Agreement and keeping global temperature rise under 1.5 degrees Celsius.
The State of Coral Reefs Right Now
There are 29 world heritage-listed coral reef sites. A recent report found that heat-stress caused by global warming had wreaked major havoc on all 29 sites. 13 of the 29 sites had experienced coral bleaching (a serious threat to reefs) more than six times since 1985. The worst bleaching events occurred in most recent years, from 2014 to 2017, as the earth’s temperature rose more dramatically. 21 of the 29 sites have had repeated or severe heat stress in the last three years.
In addition to bleaching, many coral reefs that suffer from coral bleaching also endure extreme weather, ocean acidification and pollution. Coral bleaching alone can take a reef 15 to 25 years to recover from. With the addition of other stressors, some reefs may never fully bounce back.
The Great Barrier Reef
The most famous coral reef in the world is Australia’s Great Barrier Reef off the Gold Coast. It makes up four of the 29 world heritage-listed reef sites. The Great Barrier Reef has experienced some of the worst cases of back to back coral bleaching in recent years.
Australian researchers brought their concerns to the UN World Heritage Committee in 2016. They urged the committee to list the Great Barrier Reef as “in danger” immediately. However, Professor Terry Hughes of the Australian Research Council revealed that the committee was not planning to take action on the Great Barrier Reef anytime soon. Instead, they planned to await a third outlook report from the Great Barrier Reef Marine Park Authority due in 2019.
What Happens If We Do Nothing?
If emissions follow their current patterns, 25 of the 29 global coral reefs will suffer from extreme coral bleaching twice per decade by 2040. These successive bleaching events would effectively kill most healthy coral and prevent the reproduction of new coral - essential to the reef’s recovery.
Recent reports have found that current local efforts to save the reefs are necessary, but no longer sufficient. Relying on local support is no longer enough. Jon Day of James Cook University and former director with the Great Barrier Marine Park Authority said, “We can’t just assume local responses are enough, and they must be augmented by global efforts too.”
How Do We Save the Coral Reefs?
The only way to save the coral reefs is an international effort against climate change. As a global community, we need to meet the target set by the Paris Climate Change Agreement: to keep temperature increases to no more than 1.5 degrees Celsius above pre-industrial levels.
If we are able to reduce greenhouse emissions so that they peak in 2040, the number of affected coral reef sites would decline from 25 to 14. This would give the reefs an extra 12 years to recover from bleaching events. Professor Hughes explains, “1.5C or 2C degrees won’t be a particularly comfortable place for reefs – they will still see quite regular bleaching and they will be different to how they were 15 or 20 years ago – but they will be able to survive.” At this point, survival seems to be the best we can hope for.