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The life of coral reefs is persistently under threat due to destructive fishing practices, coastal development, and land-based pollution, but perhaps its greatest threat is now climate change. According to a new study, researchers at the University of Hawaii suggest we could see entire coral reef biospheres eliminated by the end of the century.



As ocean surface temperatures rise and deoxygenation of the ocean increases acidity levels, this leads to the creation of life-starved swathes of the ocean known as ‘dead zones’. Speaking at the Ocean Sciences Meeting 2020,

By 2100, it’s looking quite grim. Renee Setter, Biogeographer, The University of Hawaii Manoa

The Future Bleached Out

For years, scientists and researchers have been warning about the state of coral reef systems around the globe. Measures such as the World Heritage Marine Programme attempt to protect reef areas due to their importance sustaining marine biodiversity, but also their value to humans living in coastal cities.

However, Setter’s latest research, which included a simulated mapping of areas with the supposed potential for new coral restoration schemes, triggered some ominous results. Running several simulations Setter and her team illustrated that most areas of the ocean that currently host these giant ecosystems would not sustain corals come 2045 and by 2100 the picture looks particularly bleak. “Honestly, most sites are out,” said Setter.

It is thought that the rising surface temperatures and subsequent acidification of the oceans are prime factors in what leads to the factors that make life for coral – the small marine invertebrates responsible for reef formation – unsustainable. When combined these elements cause severe bleaching events which make it extremely difficult for corals to recover or preserve other marine species that are dependent on the reef.

Moreover, along with changes in ocean surface temperatures and ocean acidity Setter and her colleagues also projected how other factors such as wave energy, pollution, and overfishing would impact coral reefs in the coming decades. The future for coral looks bleached out as the University of Hawaii researchers state in the paper, “This model finds that there are few to no suitable sites by the year 2100.”

Fighting Climate Change

So, while is it projected that in the next 20 years coral reefs are expected to decline 70 to 90% due to bleaching events and other anthropogenic factors such as global warming and pollution of the oceans, it was thought coral restoration schemes may offer a way back for coral reefs. Yet, these recent findings argue that this option is not a single solution in the long-term as by the year 2100 it could be a redundant practice.

Setter believes that some of the emphasis should now be shifted towards combatting the current climate emergency stating, “Fighting climate change is really what we need to be advocating for in order to protect corals and avoid compounded stressors.”

The researchers continue to advocate for coral restoration protocols but now incorporate attempts to offer ways in which CO2 emissions could be decreased to prevent further warming and deoxygenation of the oceans.

While Setter and her colleagues have been simulating models that forecast the future of coral reef systems, the consequences of climate change are already being felt by some. Since 2016, the Great Barrier Reef, Australia has experienced two major bleaching events and recent reports state it could be on the brink of a third.

As the impacts of climate change are accelerating at an alarming rate other studies also run a grim parallel to Setter’s where the elimination of coral reefs by the end of the century is concerned. Thus, efforts to stabilize the climate crisis and slow down climate change are needed now more than ever as a future without coral and their reef systems could lead to desolate oceans and severe consequences for humanity.