How has the Great Barrier Reef (GBR) been impacted by climate change and what implications could this have going forward? This is what a recent study published in Nature hopes to address as an international team of researchers investigated a connection between rising sea temperatures and mass coral bleaching on the GBR and how much danger it’s in as climate change continues to ravage the planet. This study holds the potential to help researchers, climate scientists, and the public better understand the short- and long-term impacts of climate change, specifically since the GBR is home to a wide range of marine ecology and biodiversity.
For the study, the researchers examined recent ocean temperatures within the GBR for this year, noting that over the last 400 years, the warmest temperatures were 2024, 2017, 2020, 2016, 2004, and 2022. It was also noted that during five of these six years, coral bleaching events occurred, marking a disturbing connection between increased temperatures and coral bleaching events.
“When I plotted the 2024 data point, I had to triple check my calculations – it was off the charts – far above the previous record high in 2017. I could almost not believe it,” said Dr Benjamin Henley, who is a Lecturer of Sustainable Urban Water Management at the University of Melbourne and lead author of the study. “Tragically, mass coral bleaching has occurred yet again this year. In the absence of rapid, coordinated and ambitious global action to combat climate change, we will likely witness the demise of one of Earth’s most spectacular natural wonders. When you compile all of the evidence we have, it’s the inevitability of the impacts on the reef in the coming years that really gets to me.”
With these findings, the researchers strongly emphasized the importance of taking action to safeguard the GBR from further damage, specifically from coral bleaching, resulting from human-caused climate change. This comes after the United Nations Educational, Scientific and Cultural Organization (UNESCO) World Heritage Committee decided just one week ago that the GBR was not in danger, but this study contrasts that decision. What also makes this study profound is that while the GBR is the largest coral reef system in the world, this study holds implications for coral reefs around the world, as well.
Coral bleaching results from stress caused by external stresses like decreases in water quality or increased ocean temperatures. When this happens the reefs discard the algae that protects the reef’s white skeleton while also giving the reefs their spirited colors. While reefs can heal themselves from bleaching if the stressor is removed for prolonged periods of time, having five major mass bleaching events since 2016 makes this healing process difficult.
Image of bleached coral, Great Barrier Reef, 2024. (Credit: Ove Hoegh-Guldberg)
What new discoveries will researchers make about the connection between climate change and worldwide coral reefs in the coming years and decades? Only time will tell, and this is why we science!
As always, keep doing science & keep looking up!
Sources: Nature, EurekAlert!, National Oceanic and Atmospheric Administration