The seeding of marine clouds to cool sea surface temperatures could protect threatened coral reefs from being bleached by warming oceans. Research focused on how Marine Cloud Brightening (MCB) could quickly lower sea temperatures in targeted areas.

 

There is a strong association between warmer-than-normal sea conditions and cases of coral bleaching. Bleaching is most likely to occur when a 1˚C temperature rise over a prolonged period, typically a 12-week period.

 

To brighten clouds unmanned vehicles are used to spray tiny seawater droplets, which rise into the cloud, thereby increasing their reflectivity and duration. In this way, more sunlight is bounced back into space, resulting in a cooling sea surface temperature.

 

MCB is estimated to have an annual cost of $400 million give or take depending on political, social and ethical costs. Whatever the final figure, it will be less expensive than the damage the destruction of coral would wreck on neighboring countries, the local food chain and global biodiversity.

 

Though this technique would not tackle ocean acidification, a direct result of CO² emissions, it will be a short term breathing space, of around 50 years, which could be vital for countries which rely on corals for their livelihoods while waiting for a long term solution to be found.