> For example, a common idea is to introduce iron to the ocean. This would increase plankton populations, and the plankton would then use solar power to remove

> For example, a common idea is to introduce iron to the ocean. This would increase plankton populations, and the plankton would then use solar power to remove CO2. I'm wary this leads to a "and now you have TWO problems" situation... presumably oceans full of plankton would do lots of other bad things too? Humans introducing plants/animals to control the populations of other plants/animals has worked spectacularly badly over the course of history (see: New Zealand).