Teams of Australian marine scientists have tested a technique they hope may give the Great Barrier Reef respite from coral bleaching caused by global heating. The experiment used a modified turbine with 100 high-pressure nozzles to spray trillions of nano-sized ocean salt crystals into the air from the back of a barge. The researchers hope the tiny salt crystals will mix with low-altitude clouds, making them brighter and reflecting more sunlight away from the ocean surface. Daniel Harrison of Southern Cross University says if the trial can be successfully scaled up it might buy the reef a decade or two, but no technological fix will work unless global heating can be restrained