I feel like they've been talking about this since I was a kid. I remember reading in school about phytoplankton as a carbon sink and how it can be used to fight climate change back in the early 2000's, or am I losing my mind?
Edit after reading more carefully. Yes they've been working on it, it's the potential side effects that are the big deal
Researchers have long known that adding iron to the sea leads to blooms of phytoplankton (back in the 1980s, one scientist declared: “Give me a half tanker of iron, and I will give you an ice age”),