This has been done, I think most people know this.<p><a href="https://www.theguardian.com/environment/2012/oct/15/pacific-iron-fertilisation-geoengineering" rel="nofollow">https://www.theguardian.com/environment/2012/oct/15/pacific-...</a><p>You can track down the 8 years of followup articles and research papers.<p>There is no evidence it didn't work. There's evidence it did.<p>The trick is, tie it to fishing and it might make a difference. Or it might just take pressure off fisheries.<p>You have billions yet to eat more meat, so hurry up with your lab grown meat or start doing things like this, that also should get the same subsidies as things like solar power.