The world’s largest coral reef system, the Great Barrier Reef off the coast of Australia, is under severe threat from rising global temperatures.
A report published in Marine Science in May 2026 states that coral bleaching or the whitening of corals due to unusually warm seawater has reached the highest levels in recorded history.
To save this invaluable marine ecosystem, scientists are now using an innovative marine geo‑engineering technology called Cloud Brightening.
Coral bleaching and damage to marine ecosystems: If seawater temperature rises by just 1 degree Celsius, the symbiotic algae living inside corals die; these algae give corals their color and nutrients. If the reef is destroyed, about 25% of the ocean’s fish could lose their habitat, which would deal a severe blow to the global fishing industry.
Cloud Brightening or cloud whitening technology: By 2026 Australian scientists are working on this groundbreaking technical solution to tackle the crisis:
- Method: Special ships spray seawater as extremely fine particles or aerosols toward clouds.
- Temperature reduction: These saltwater particles make clouds whiter and more reflective. Brighter clouds reflect sunlight and heat back into space, keeping the sea surface cooler.
- Effectiveness: A May 2026 pilot project showed that this technology could reduce the temperature in targeted reef areas by about 0.5 degrees Celsius, helping to protect corals from bleaching.
Geo‑engineering can temporarily save corals, but it is not a permanent solution. If global carbon emissions are not rapidly reduced, even this advanced technology will not prevent a major crisis in the oceans.
