Coral reefs, often described as the "rainforests of the sea," are facing an existential threat. A new study published in Nature reveals that climate change and rising ocean temperatures are pushing coral reefs toward eventual extinction, with devastating consequences for coastal protection, marine biodiversity, and millions of people worldwide.
The research shows that reef growth is already unable to keep pace with accelerating sea-level rise. By analyzing more than 400 reef sites across the tropical western Atlantic, scientists found that 70% of reefs will shift into a state of net erosion by 2040, meaning they will lose more structure than they build.
If global warming exceeds 2 °C, nearly all reefs (99%) will be eroding by 2100. This would leave coastlines far more exposed to flooding, storm surges, and erosion, magnifying the impacts of rising seas.
Coastal protection at risk
Currently, coral reefs provide natural protection to an estimated 5.3 million people and shield coastal infrastructure worth $109 billion every decade. But as reefs disappear, water depths above reef surfaces are expected to increase by 0.7–1.2 meters by 2100, dramatically weakening their ability to buffer wave energy.
“Coral reefs have safeguarded coastal communities for thousands of years. Without urgent climate action, that protection could vanish within decades,” warn the study’s authors.
The researchers note that reef restoration projects, such as coral outplanting, can provide local benefits. However, even under the most optimistic scenarios, restoration would only offset sea-level rise impacts by a few tenths of a meter by 2100 — and only if paired with aggressive global climate mitigation.
This study underscores the critical importance of keeping global warming below 2 °C. Without decisive action, the world risks losing coral reefs entirely — with catastrophic consequences for marine ecosystems, coastal resilience, and human livelihoods.
“Coral reefs are on the front line of the climate crisis,” the authors conclude. “Their fate depends on the choices we make this decade.”
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