A million and a half Aussies visit the Great Barrier Reef each year (before Covid, anyway). But their grandchildren may never have that pleasure, because if we don’t act decisively on climate change, it will likely be dead.
- Coral reefs are enormously important ecologically.
- The Great Barrier Reef is the largest and most important coral reef in the world.
- Coral begins to die as water temperatures rise.
- On present trends, global temperatures are predicted to rise above the levels critical for coral before the end of the century.
- The Great Barrier Reef could be dead within 70 years.
The future of the Reef
Coral reefs provide habitat for an enormous number of marine species. About 25% of the ocean’s fish depend on healthy coral reefs. The Great Barrier Reef is home to literally thousands of species of corals, molluscs, jellyfish, fish and other marine life.
The Reef also generates $6bn a year (in a normal year) and 60,000 jobs in tourism. Economists estimate its economic value at $56bn.
Yet the Reef is suffering because of pollution and warming ocean waters, as well as from storms and predation by the crown of thorns starfish. When El Niño weather conditions warm the waters close to Australia, the coral is stressed and “bleached”, a process which will eventually kill the coral unless the coral has time and cooler temperatures to recover.
The Reef has experienced 10 bleaching events in the past four decades. In 2017, after several years of unusually warm water, about two thirds of the Reef experienced bleaching. The corals are now recovering, and should be restored to past levels if given time – about ten years is required.
However if global warming continues on its present trajectory, by 2050 bleaching events will be too frequent to allow the coral time to recover. By the end of the century, if not sooner, global temperatures will rise more than 2°C and this will be sufficient to completely kill the coral. The Reef will then no longer exist in its present form.
Hope for the future
There is hope for the future, but it requires concerted action.
- The world needs to act decisively on climate change, to keep the rise in global temperature to less than 2°C. This will require net zero emissions by 2050 and carbon reduction beyond 2050.
- Coral is resilient, and we can hope that the coral of the Reef will be resilient enough to survive the trauma inflicted on it in recent years and the next few decades, and adjust and restore in the period when the global temperature rise stabilises at about 1.5-1.8°C (if the world acts).
- Australian conservationists are planning to preserve hundreds of species of coral in a biobank, which can be used to replant the Great Barrier Reef in the event of its destruction.
The world’s coral
The precarious future of the Great Barrier Reef is echoed in concerns about the future of all coral reefs globally. This month the Global Coral Reef Monitoring Network released its Sixth Status of Corals of the World: 2020 Report.
This report highlighted the high value of coral reefs (tourism and ecological services valued at US$2.7 trillion per year worldwide) and their importance for marine life.
Globally, 14% of coral reefs were lost in the decade 2009-2018, mainly through coral bleaching caused by global warming. Many of the world’s coral reefs remain resilient and can recover if conditions permit, but the increased frequency of bleaching events is beginning to overwhelm these reefs’ resistive capacity.
The world could lose all coral reefs by the end of the century.
But again, there is the hope that the world will act, and be able to restore the damaged reefs when conditions are right.
Australia’s part in the reef’s destruction
Australia is complicit in the Reef’s potential destruction. The Reef already faces threats from storm destruction and infestations of the crown of thorns starfish. But other human threats are the real problem:
- Keeping global temperature rise to less than 2°C is critical for the Reef’s future. But Australia is ranked last of almost 200 UN member countries for effective climate action. Our record on refusing to commit to net zero emissions, despite all the advantages Australia has to produce cheap renewable energy, is shameful. If Australia fails to act, how can we expect other countries with fewer renewable energy sources to act?
- Global warming will also increase the frequescy of destructive storms in the region.
- Not only does Australia continue to allow new coal mines to open, but at least one – the Bravus (formerly Adani) mine – is in a coastal area likely to affect the reef, if not through mining runoff, then through the port facilities.
- Agricultural runoff deposits sediment, fertilisers, pesticides and herbicides in the water near the Reef, which also have a destructive effect on coral.
- In June, UNESCO’s scientific advisors recommended adding the Reef to the ‘in danger’ list, because of the threat from climate change. Australian Environment Minister Sussan Ley lobbied against the “in danger” assessment without changing any of Australia’s destructive approaches to climate change.
All this suggests the government is more interested in protecting itself from criticism than in protecting the Reef.
So will your grandchildren be able to visit the Reef?
This is unlikely, unless this government totally changes its approach, from doing the minimum while trying to give a positive impression, to serious action to move quickly from fossil fuels to renewables.
I have looked at this question in greater detail, with many references, in Coral reefs and global warming. Please give it 5 minutes of your time – for the Reef’s sake.