Introduction
Australia’s pride—the Great Barrier Reef—is “disappearing,” with some regions now devoid of living coral! The world is currently experiencing the fourth large-scale coral bleaching event, and 83 countries are already affected.

The Great Barrier Reef Faces Its Worst Loss in 39 Years
As the world’s largest living structure, Australia's Great Barrier Reef has long been a symbol of ecological wonder. Stretching along the Queensland coast, this reef system is larger than Italy, supporting thousands of species of fish, corals, mollusks, and other marine life.

However, this iconic destination is now facing an unprecedented crisis. Australian authorities have reported the most severe loss of living coral ever recorded in the reef’s history. The global community is still undergoing the fourth large-scale coral bleaching event, and without urgent intervention, many regions of the reef could face total coral disappearance.

This summer, the Great Barrier Reef experienced its sixth mass bleaching event since 2016, marking the second consecutive year of such a phenomenon. Authorities stated that the loss of living coral in most areas of the reef was the most severe in 39 years of surveys.

The Australian Institute of Marine Science divided the Great Barrier Reef into three sections: northern, central, and southern. Data revealed that in just one year, the southern section experienced a nearly one-third reduction in live coral cover, the northern section lost a quarter, and the central section declined by 14%.

Last year, a study found that temperatures above the reef had reached their highest levels in at least 400 years. Mike Emslie, head of the long-term monitoring project, emphasized, "While there is still considerable coral cover, we have observed the largest single-year decline on record."

The Fourth Global Coral Bleaching Crisis
Due to record-breaking global temperatures from 2023 to 2024, the world is still in the midst of its largest-ever coral bleaching event. According to NOAA’s Coral Reef Observation Program, the high temperatures have already damaged nearly 84% of coral reef areas worldwide, including the Great Barrier Reef. So far, at least 83 countries have been affected.

This bleaching event began in January 2023 and was declared a global crisis in April 2024. The severity of this crisis far exceeds the last major event between 2014 and 2017, which saw 68.2% of coral reefs bleach due to high temperatures.

Corals can survive short-term temperature spikes, but when high temperatures persist for weeks beyond critical thresholds, corals expel the symbiotic algae that give them their color, leading to bleaching. Bleached corals are not immediately dead, but they become fragile and more susceptible to disease.

Can Coral Reefs Recover?
Although coral reefs can often recover from global bleaching events, the ecological strength of these systems after recovery is typically lower than before. Whether these ecosystems can recover now remains uncertain.

The UN Intergovernmental Panel on Climate Change (IPCC) previously warned that if global temperatures rise by 1.5°C, 70% to 90% of tropical coral reefs will disappear. The reality may be even more complicated. The report explicitly warned that tropical coral reefs would face extremely high risks if temperatures rise by just 1.2°C, with most evidence suggesting that coral-dominated ecosystems will no longer exist at this temperature or higher, leaving many regions with almost zero coral coverage.

What Can Be Done?
The most obvious solution is to quickly and drastically reduce greenhouse gas emissions. Additionally, there are direct intervention measures such as cultivating heat-resistant corals to “repair” reefs, shading reefs by brightening clouds, and improving local environments to boost coral resilience.

However, coral scientists emphasize that these methods should never replace climate action. There is still fierce debate in the scientific community regarding the efficacy of these intervention measures.

The minimum risk of ecosystem collapse is still to halt global warming. Without this, the remaining corals will continue to raise the white flag and sound the alarm.

Conclusion
The Great Barrier Reef is an irreplaceable natural treasure, crucial to the stability of the global ecological chain. Addressing its ecological crisis is urgent and must be prioritized for the health of our planet's future.