The Great Barrier Reef has once again avoided inclusion on UNESCO’s List of World Heritage in Danger, despite growing scientific concerns related to the impact of climate change and the successive mass bleaching events recorded in recent years.
The decision is contained in a draft resolution that will be considered this week by the World Heritage Committee, meeting in Busan, South Korea. The document acknowledges the investments made by Australia in the management and conservation of the reef, but simultaneously expresses “grave concern” about the deterioration of ecological conditions, the repeated coral bleaching events, and the persistent effects of climate change.
The recommendation comes five years after the Australian government managed to block a similar proposal advocating the reef’s inclusion on the List of World Heritage in Danger.
Although the final decision could still be amended during the committee deliberations, experts from the University of New South Wales (UNSW) say the central issue remains unresolved: the future of one of the planet’s most important marine ecosystems.
“The fact that it is not included on the list does not solve the problem. It only means the situation will be reassessed in a few years,” says Lucas Lixinski, Professor of International Law and World Heritage specialist at UNSW, quoted in a statement.
Record temperatures increase risk to corals
The UNESCO decision comes in a context of worsening global climatic conditions. The oceans recently recorded June as the hottest month on record, while marine heatwaves have become more frequent and intense.
In the last decade, the Great Barrier Reef has been affected by six mass bleaching events, a phenomenon that occurs when corals are subjected to temperatures higher than those they can withstand for extended periods.
According to Alex Sen Gupta, a professor at UNSW and a specialist in marine heatwaves, corals respond to local thermal conditions rather than global averages.
“Corals do not experience average temperatures. What matters is the water temperature at the place where they live,” he explains.
When thermal stress is prolonged, corals expel the microscopic algae that provide them with nutrients and color, turning white. If elevated temperatures persist, bleaching can lead to the death of the organisms.
Recovery does not mean a return to the original state
Before a new bleaching episode occurred in 2024, coral cover had reached high levels in several areas of the Great Barrier Reef. However, scientists warn that this indicator does not necessarily reflect the overall health of the ecosystem.
A large part of the observed recovery resulted from the proliferation of corals of the genus Acropora, fast-growing species but particularly vulnerable to marine heatwaves, cyclones, and predation by the crown-of-thorns starfish.
“A high coral cover does not mean that the reef has returned to the same ecological state as before,” notes Sen Gupta.
According to the researcher, the composition and diversity of coral communities have changed significantly, potentially making the ecosystem more vulnerable to future disturbances.
UNESCO assesses management, not only ecological state
Experts note that UNESCO’s World Heritage Convention, adopted in 1972, was not designed as a tool solely scientific for assessing the health of ecosystems.
Beyond scientific data, the committee also evaluates how States manage and protect sites classified as World Heritage.
“UNESCO seeks to determine whether governments are acting as proper custodians of these sites of exceptional universal value,” explains Lucas Lixinski.
In this context, Australia has been praised for its environmental management efforts, including measures to improve water quality, control the proliferation of the crown-of-thorns starfish, and restore degraded areas of the reef.
List of World Heritage in Danger remains enveloped in debate
The potential inclusion of a site on the List of World Heritage in Danger continues to generate controversy. Although originally designed to mobilize technical and financial international support for threatened areas, the designation has progressively come to be regarded as a negative indicator of a country’s environmental performance.
“This list ended up gaining a reputation as a mark of shame for governments,” says Lixinski.
According to the expert, the designation could bring tangible environmental benefits by attracting more funding, international assistance, and monitoring mechanisms, but would simultaneously constitute a political setback for the Australian Government.
Local management is not enough to curb global warming
Despite conservation efforts, scientists warn that the main threat to the Great Barrier Reef remains global warming.
Local measures can increase the resilience of corals and reduce additional stressors, but they cannot eliminate the effects of rising ocean temperatures.
“Even the best-managed reef in the world cannot escape a warming ocean,” says Sen Gupta.
The researcher argues that restoration programs can be useful in specific locations, but they are not a solution capable of compensating for the losses caused by climate change at the scale of the entire reef system.
Reducing emissions remains decisive
Experts emphasize that the reef’s future will depend as much on local management as on international decisions to reduce greenhouse gas emissions.
According to Alex Sen Gupta, the scientific community has long known the causes of the problem and the measures needed to address it.
“We understand the origin of the problem and know what needs to be done: global greenhouse gas emissions must fall rapidly,” he asserts.
“The real challenge is to translate this knowledge into concrete actions, at the scale and speed required by the situation,” he concludes.
The final decision on the status of the Great Barrier Reef is expected in the coming days, during the UNESCO World Heritage Committee meeting in Busan.
