Officials have confirmed that Australia's iconic Great Barrier Reef is undergoing another mass bleaching event, marking the fifth occurrence in eight years. Bleaching happens when heat-stressed corals expel the algae vital to their life and color. Urgent climate action is emphasized by scientists to ensure the reef's survival, as the frequency of these events increases due to rising sea temperatures.

The reef, stretching over 2,300km along Australia's north-east coast, is the world's largest coral system and a highly diverse ecosystem. A recent aerial survey covering 320 reefs revealed widespread bleaching after a summer of elevated sea temperatures. The severity of the damage is being assessed through in-water examinations, with the southern zone experiencing the worst bleaching in nearly two decades.

Despite the reef's resilience in the face of previous challenges, such as cyclones and starfish outbreaks, record-breaking global sea temperatures continue to trigger bleaching events. Bleaching was even observed on Lord Howe Island, the world's southern-most reef. Recognized as a UNESCO World Heritage site for over four decades, the Great Barrier Reef faces serious threats from warming seas and pollution.

Australian governments have been challenged to prevent the reef from being declared "in danger" by UNESCO, which could result in the loss of its heritage status. Climate change is identified as the primary threat to coral reefs globally, prompting increased funding for reef conservation and stronger emissions-reduction targets from the Australian government.

The frequency and scale of mass bleaching events are alarming, with their occurrence contingent on global emissions reduction efforts. Critics highlight the discrepancy between Australia's rhetoric on protecting the Great Barrier Reef and its continued support for the coal and gas industry, which contributes to climate change and, consequently, the bleaching of the reef.