Regulating Iron Fertilization
While I think regulation are a good idea, an outright ban would be an international relations mess and would make the problem worse, not better. Here's one example why:
It's almost 100% certain that either India or China is considering large-scale iron fertilization as a way of complying with post-2012 Kyoto protocol commitments. Both nations are considering joining as of 2012, and both nations have enormous carbon dioxide problems, so the pressure to use iron fertilization will be irresistable. India has already announced a 2009 experiment being done in conjunction with the Wegner Institute under Victor Smetacek -- who is known as a proponent of the technique. We can bet it's going to happen, and it's going to be big.
So, that means we should quickly ban iron fertilzation now, right? Wrong. It won't work out that way. Any short-term effort to ban or super-restrict the technique will be seen as premature and sloppy, and will be ignored.
On the other hand, if on iron fertilization is intelligently regulated, and the regulations are developed in an open and even-handed way, and if those regulations are then applied and tested on current small-scale operations being done by various academic institutions and commercial vendors then those regulations will have "history" and it's more likely that India or China, or whoever, can be persuaded to abide by them.