The Great Barrier Reef is undergoing a severe coral bleaching event with about 75% affected.

This event is part of a worldwide phenomenon where over half of global coral reefs are experiencing mass bleaching due to unprecedented oceanic heat.

Coral bleaching is categorized from one to five, with the most extreme cases affecting over 90% of a reef's coral cover, leading to potentially massive coral mortality.

The current crisis is a direct consequence of climate change, with marine heatwaves causing corals to release symbiotic algae, which can result in the corals' death.

Experts are calling for urgent measures to combat climate change and protect coral reefs, emphasizing that there is a limited window for action.

The UN Environment Programme warns that if aggressive actions to reduce emissions are not taken, the world may see a catastrophic rise in temperature, endangering 99% of coral reefs.