Plans to dump iron as climate fix attracts debate

A company called Planktos is planning to dump tons of iron into the sea. According to them, iron, a key nutrient in plankton growth, will boost plankton growth, which in turn will absorb carbon from the atmosphere. However, GreenPeace doesn't seem to buy this argument, and is sending a ship to intercept this operation.
http://news.nationalgeographic.com/news/2007/07/070725-iron-ocean.html