A Shipload of Iron Fixes Global Warming?

So the other night my friend Greg was all liquored up and sent me the following text:

I remember after picking up a rusty nail just now in the trail I had a high school science teacher tell the class one time that there was a theory if you took a freighter full of iron shavings out to the Arctic and thank it that the Iron would feed plank dinner something that would produce oxygen and such a great amount that it would remove most of the unwanted CO2 from the air, but nobody would try it because for the risk

Just reading it made me a little drunk too — so I splashed some cold water on my face and tried again. This conjecture is something I had never heard of, but it was interesting enough that I did a bit of Googling (ya know, “I did my own research”).

And lo and behold, it turns out that this is a real thing. The specifics are not captured in their exacting details in Greg’s text (though we all thank him for his effort). This was a serious proposal from influential oceanographer John H. Martin, best known for his research on the role of iron as a micronutrient for phytoplankton; and the “Iron Hypothesis,” which suggests that iron fertilization could increase carbon dioxide fixation in the oceans. He also developed the “Martin curve,” which describes the export of particulate organic carbon to the ocean floor. So, in short, Martin knew his stuff when it came to oceanic carbon loads.

In 1990, Martin’s idea was published in the journal Paleoceanography and Paleoclimatology.¹ The 10-cent summary is that he felt would could recreate conditions during the last Ice Age which resulted in more carbon being sequestered — and thus mitigate the unchecked warming we’re going through now. Here, in simple terms, is how it would work: