Global warming is damaging the Great Barrier Reef

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Amanda Wilcox

One of the seven wonders of the natural world is currently in mortal peril. Australia’s Great Barrier Reef, which spans 2,300 miles of the Queensland coast, is experiencing its most extensive bleaching event in recorded history.

It is the third mass coral bleaching in 18 years. Formerly, mass coral bleachings only occurred approximately once every thousand years.

Ocean temperatures and acidity levels beyond corals’ range of tolerance, which are directly associated with anthropogenic climate change, force corals to expel the zooxanthellae algae that provide them with approximately 90 percent of their nutrition. Without a source of food, corals become critically ill and may die.

In order to rescue just 10 percent of the reef, global average surface temperature change must be limited to an increase of just 1.5 degrees celcius. This tall order will require brisk action, as average global temperatures have already increased approximately 1 degree celcius.

Because Australia has stewardship of this “rainforest of the sea,” it is essential that the newly elected members of its Senate and House of Representatives make restorative programs for the reef a high priority.

However, it is unrealistic to expect Australian policy action alone to secure the reef a healthy future. Even though the U.S. is on the opposite side of the world, its fuel-burning activities play a significant role in average surface temperature change around the entire globe. Full cooperation of the U.S. (which ranks second only to China in fossil fuel usage) and thorough implementation of the Paris Climate Accords will be required to slow increasing ocean temperatures and acidity levels.

It is not easy to mobilize the electorate to demand action against climate change. Marginal year-on-year changes in temperature and weather patterns can be difficult to discern; impacts can appear to be distant in the future and far from home.

However, the shocking rapidity of the Great Barrier Reef’s decline is a testament to the true emergency that climate change is today.

Consequences of the damage that the reef has sustained are expected to be widespread; coral is a keystone species in the oceanic ecosystem. Reefs provide habitat and shelter for up to 25 percent of marine species, from tropical fish and mollusks to sea turtles, sea sponges and sharks.

Some of these species are endemic to the Great Barrier Reef, so they could become endangered or even extinct as a result of habitat loss. A biodiversity decrease in the Great Barrier Reef ecosystem could have ripple effects throughout the entire ocean food web.

Furthermore, the Great Barrier Reef provides invaluable ecosystem services to humans. It buffers the shoreline from tropical storms, protecting coastal homes and businesses from wave damage. Numerous fisheries depend on the reef’s health and productivity, as it acts as a nursery for juvenile fish. Damage to the reef, therefore, could potentially affect the global food supply. Ecotourism generates about $5 billion in revenue for Australia’s economy each year, and that figure could suffer if the splendor of the reef is compromised. Many indigenous groups in Australia depend on the reef for food and income.

Even though the Great Barrier Reef is so large that it can be seen from outer space, it is one of the world’s most delicate ecosystems. Without immediate action to mitigate the effects of warming ocean temperatures, the world stands to lose a spectacular treasure.

Author’s note: This article is adapted from one that I wrote for the PBS NewsHour on June 7, 2016.