Ocean seeding fails the acid test
It all seemed too easy by half: to beat global warming just sprinkle some iron in the ocean, then watch as algae bloom en masse, sucking up carbon dioxide by the tonne. Now the idea is looking increasingly unlikely to go ahead in a big way. In the wake of a UN moratorium on the practice, the latest research suggests that seeding will trigger the build-up of an acid that can be lethal to marine organisms and humans.