Overview

• Average sea surface temperatures around Australia reached record highs in 2024, according to the Australian National University.
• Surveys of 124 reef sites by the Australian Institute of Marine Science from August 2024 to May 2025 showed the largest annual coral declines ever recorded in the reef’s northern and southern regions.
• Fast-growing Acropora corals suffered the worst losses during this bleaching event as heat stress forced them to expel symbiotic algae.
• This marks the sixth mass bleaching of the Great Barrier Reef in nine years, highlighting its shrinking window for recovery between heatwaves.
• Australia is preparing new emissions reduction targets under the Paris Agreement even as it remains one of the world’s top coal exporters.