Climate at a Glance: The Great Barrier Reef

Aerial view of Arlington coral reef at The Great Barrier Reef near Cairns in Queensland, Australia. Licensed from 123rf.com

Key Takeaways:

  • Coral coverage on the Great Barrier Reef (GBR) set the record for the highest amount measured in 36 years of consistent record keeping by the Australian Institute of Marine Science (AIMS) in 2022, breaking the record set the previous year.
  • AIMS survey of the GBR found that between August 2021 and May 2022, average hard coral cover in the upper region and central areas of the reef increased by around one third.
  • Coral has existed continuously for the past 40 million years, surviving temperatures and carbon dioxide levels significantly higher than what is occurring today.

Coral has existed continuously for the past 40 million years, surviving temperatures and carbon dioxide levels significantly higher than what is occurring today.1

Objective scientific evidence refutes claims in recent decades that warming oceans and coral bleaching are resulting in a decline of the Great Barrier Reef (GBR). Ten years ago, science and the media suggested the GBR would be almost gone today due to the posited effects of climate change.2 This claim was based on a single scientific study published in October of 2012 which analyzed GBR coral loss over a 27 year period.3 The researchers primarily blamed coral bleaching in response to warmer waters and tropical cyclones, suggesting both are exacerbated by climate change and the GBR’s decline.

A 2021 report from AIMS showed the amount of coral impacted by recent bleaching events was much less than what was initially claimed by researchers and the media. In addition, as has occurred at coral reefs around the world that have suffered bleaching, most of the GBR’s corals have recovered.4

AIMS reported just 22 percent of the GBR, had bleached, not the more than 93 percent claimed.  AIMS also discovered more than 75 percent the bleached coral had recovered. AIMS wrote, “After a series of severe and widespread disturbances over the last decade, the Great Barrier Reef is currently in a recovery window with coral cover rising in all three regions.”

The AIMS 2022 report on the GBR contained more good news:5

“Continued coral recovery leads to 36-year highs across two-thirds of the Great Barrier Reef “

As seen in Figure 1, the 2022 data show the rise in coral coverage in the GBR since 2019 has been dramatic.

Figure1: Australian Institute of Marine Science GBR coral coverage data plotted by Dr. Bjorn Lomborg.

Over the past 36 years of monitoring, coral reefs in the GBR have shown an ability for recovery after disturbances such as tropical storms and coral bleaching events. In 2022, widespread recovery has led to the highest coral cover recorded in the Northern and Central GBR, largely due to increases in the fast-growing Acropora corals, which are the dominant group of corals on the GBR.6

Data show the GBR’s corals are thriving and expanding, as is true for other coral reefs around the world, providing clear evidence climate change is not causing a decline.


References:

  1. Global Reef Project, “Coral Reef History,” accessed July 26, 2021, http://globalreefproject.com/coral-reef-history.php
  2. Sydney Morning Herald, Nicky Phillips, “Great reef catastrophe”, October 2, 2012, https://www.smh.com.au/environment/conservation/great-reef-catastrophe-20121002-26vzq.html
  3. Proceedings of the National Academy of Science, De’Ath et.al., October 1, 2012, “The 27–year decline of coral cover on the Great Barrier Reef and its causes,” https://doi.org/10.1073/pnas.1208909109
  4. AIMS, Long-Term Monitoring Program – Annual Summary Report of Coral Reef Condition, 2020/21, https://www.aims.gov.au/reef-monitoring/gbr-condition-summary-2020-2021
  5. AIMS, Long-Term Monitoring Program, Annual Summary Report of Coral Reef Condition 2021/22, https://www.aims.gov.au/monitoring-great-barrier-reef/gbr-condition-summary-2021-22
  6. Living Oceans Foundation, Andrew Bruckner, Ph.D., September 13, 2014, Rebirth of the Reef, https://www.livingoceansfoundation.org/acropora-rebirth-of-the-great-barrier-reef/