According to aerial surveys, a marine heatwave triggered widespread coral bleaching in one-third of the Great Barrier Reef. The extent of this bleaching is worrying, with surveys showing symptoms in 75% of coral reefs.
According to Australian media on April 6, the discovery suggests that the start of a global bleaching event may be announced, as coral reefs around the world are facing more frequent and intense marine heatwaves due to global warming.
According to an aerial survey conducted by the Great Barrier Reef Marine Park Authority, half of the surveyed area showed high to very high bleaching levels, with 10% classified as extreme, indicating severe distress and more than 90% of corals affected.
This distress is not confined to the northern region, but spreads across three parts of the Great Barrier Reef – northern, central and southern – on a scale unprecedented in recent years.
"Previous bleaching events have spread to two reef areas, usually the northern and central regions," said Richard Lake, WWF's head of oceans for Australia.
The importance of these findings cannot be overstated. Previous bleaching events have typically affected only two areas of the Great Barrier Reef, but this time, all three areas have been affected. As coral bleaching events become more frequent, significant events have occurred in 1998, 2002, 2016, 2017, 2020, 2022 and now 2024.
The bleaching event highlights the existential threat of climate change to coral reefs around the world. Rising global temperatures have exacerbated greenhouse gas emissions, leading to more frequent and severe marine heatwaves, pushing coral ecosystems to the brink of collapse.
Lisa Schindler, Marine Conservation Australia's Coral Reef Campaign Manager, aptly described the situation as alarming and highlighted the urgent need for action to mitigate climate change and protect coral reefs.
The Australian government has pledged to reduce national emissions by 43% by 2030 and achieve net-zero emissions by 2050, in line with international efforts to limit global warming to below 2 degrees Celsius. However, the current trajectory of emissions reduction is likely to still lead to catastrophic consequences for coral reefs, as projections show that only 1% of corals will be able to survive a temperature rise of 2 degrees Celsius.
Faced with concerns about World Heritage status, Australia was faced with a request at a meeting in July to make a full display of the Great Barrier Reef's conservation measures so as not to be listed as "dangerous". However, accusations against UNESCO against the federal government for deception and inadequate actions have raised doubts about Australia's commitment to coral reef conservation.
In response to the increasing pressure, the Australian government has highlighted its efforts to combat climate change and protect the Great Barrier Reef. Australia's Federal Environment Minister Tanya Pribersec reaffirmed the government's commitment to reaching net zero emissions and investing in coral reef conservation projects. However, critics argue that these efforts may not address the root causes of coral bleaching and that more comprehensive and ambitious climate action is necessary.