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The 2023–2025 global coral bleaching now affects 84% of the world’s reefs, driven by extreme sea temperatures from worsening climate change.

08 Jun 2025 2 min

The global coral bleaching crisis has reached a new peak. Latest data reveal that from early 2023 to 2025, coral bleaching has impacted more than 84% of the world’s reef ecosystems. This figure marks the most extensive bleaching event in modern history, surpassing previous records and serving as a dire warning for global ocean health.

Marine heatwaves, resulting from climate change and El Niño anomalies, have driven surface sea temperatures above 20.8°C in many tropical regions. This domino effect is hitting the Caribbean, Florida Keys, Australia’s Great Barrier Reef, the South Pacific—such as Fiji and Kiribati—as well as Asian coastlines, including Indonesia. No region is entirely spared; even Raja Ampat, once considered resilient, is now affected.

These conditions have led to massive coral die-offs, with some regions reporting losses of 50% to 93% of their coral populations. Scientists now describe affected reefs as “graveyards of corals,” reflecting dying ecosystems and disappearing biodiversity.

Rising greenhouse gas emissions accelerate global warming, fueling extreme global ocean temperatures. NOAA and other international agencies report 2023–2025 as the period with the highest recorded sea surface temperatures. The ENSO phenomenon further intensifies oceanic heat stress. While global bleaching events have occurred four times since 1998, this event is by far the largest in scale and impact.

Coral reef destruction threatens not only a single species, but also a third of all marine species that rely on reefs for habitat. The loss of coral also means the loss of food sources, coastal protection, and economic support for millions in coastal communities. Tourism, fisheries, and shoreline defense all depend heavily on healthy coral reefs.

Scientists and conservationists are working tirelessly to stem the tide of destruction. Restoration efforts range from transplanting juvenile corals in the Florida Keys to researching heat-tolerant coral strains. Satellite monitoring and digital mapping—like the Allen Coral Atlas—are essential tools for detecting and responding to this crisis in real time.

Nevertheless, major challenges persist. More frequent marine heatwaves mean natural ecosystem recovery is increasingly difficult. Ecosystem restoration now demands a cross-sectoral approach, including climate policy, energy transition, and active participation from coastal communities.

If global emissions aren’t drastically reduced, the IPCC projects that 70–90% of coral reefs could disappear within the next two decades. With sea temperatures continuing to break records, the future of coral reefs—and the millions of lives dependent on them—is in grave danger.

This global coral bleaching crisis is a stark reminder that climate change is spiraling out of control. The fate of coral reefs now depends on collective global action to reduce emissions, accelerate clean energy transitions, and strengthen marine conservation.