There are reasons to think it may be effective. But I try to live by "The first principle is that you must not fool yourself – and you are the easiest person to fool." I want additional experiments to make findings robust. In particular, even if small fertilization inputs reliably lead to large biomass increases, we need to know how much of that added biomass sinks to the deep ocean before we know how effective it is at sequestration. That can mean trying to track carbon movement over complicated food webs.