The alarming increase in coral reef bleaching has now impacted 84% of global reefs, marking the most severe event recorded, the International Coral Reef Initiative (ICRI) reported on Wednesday.
This represents the fourth global bleaching event since 1998. It has outdone the bleaching from 2014-2017, which had affected around two-thirds of coral reefs, according to the ICRI – a coalition including more than 100 governments and organizations. The ongoing crisis, which began in 2023 due to warming ocean conditions, has no definite end in sight.
“We may never see the heat stress that leads to bleaching dip below the threshold that sparks a global event,” stated Mark Eakin of the International Coral Reef Society. Eakin, a retired head of NOAA’s Coral Reef Watch program, warned, “We are witnessing dramatic changes to our planet’s surface and the oceans’ capacity to provide for life and livelihoods.”
The previous year was recorded as Earth’s hottest, with a significant amount of heat absorbed by the oceans. The average annual sea surface temperature, notably away from the polar regions, reached a peak of 20.87 degrees Celsius (69.57 degrees Fahrenheit), which is detrimental to the coral ecosystem.
Coral reefs are vital for seafood production, attract tourism, and serve as a barrier protecting coastlines from erosion and storms. Known as the “rainforests of the sea,” coral reefs sustain an impressive biodiversity, hosting about a quarter of all marine species. However, when ocean temperatures rise, the symbiotic colorful algae within corals release toxins, leading corals to expel them. This process leaves behind a bleached white skeleton and greatly endangers the coral’s survival.
The current bleaching has forced NOAA’s Coral Reef Watch to expand its bleaching alert scale to represent the increased mortality risk for corals. Conservation and restoration efforts are in motion—a Dutch lab is cultivating coral fragments from places like the Seychelles with hopes of repopulating damaged reefs, while projects in Florida are rehabilitating heat-impacted corals.
However, experts stress the necessity of reducing greenhouse emissions, particularly from burning fossil fuels, as a remedy to climate change affecting coral ecosystems. “Addressing the fundamental cause of climate change is crucial to protecting coral reefs,” Eakin emphasized, calling other efforts mere temporary fixes.
“It’s critical for people to understand their impact—inaction seals the fate of coral reefs,” added Melanie McField, co-chair of the Global Coral Reef Monitoring Network’s Caribbean Steering Committee.
This development follows President Donald Trump’s aggressive policy direction that supports fossil fuel usage while rolling back clean energy initiatives, claiming it drives economic growth. Eakin commented, “Current governmental policies dismantling ecosystem protections will have dire consequences.”