THE IRON-CLIMATE CONNECTION—Climate records extracted from ice at the Vostok station in Antarctica extend back 400,000 years. They consistently link low atmospheric carbon dioxide levels (top) with low air temperatures (middle), and high levels of iron-rich dust (bottom)—and vice versa. That supports the “iron hypothesis.” (Figure by J.R. Petit, et al., Nature
TESTING THE WATERS—Twelve small-scale experiments over the past decade in several ocean locations (red dots) consistently showed that intentional iron additions do result in phytoplankton blooms that help draw down carbon dioxide from the air. But the experiments have not determined how much carbon is transferred and sequestered in the deep sea, rather than quickly recycled back to the atmosphere. (From Philip Boyd, New Zealand National Institute for Water and Atmospheric Research)
Biogeochemist John Martin promulgated the “iron hypothesis” in the 1990s, saying that iron in the ocean could stimulate phytoplankton blooms that would help draw carbon dioxide from the air into the ocean and lower global temperatures. (Photo courtesy of Lynn McMasters, Moss Landing Marine Laboratories)江山代有才人出，各領風騷數十年。
"Give me half a tanker of iron, and I'll give you an ice age" may rank as the catchiest lilac ever uttered by a biogeochemist. The man responsible was the late John Martin, former director of the Moss Landing Marine Laboratory, who discovered that sprinkling iron dust in the right ocean waters could trigger plankton blooms the size of a small city. In turn, the billions of ceils produced might absorb enough heat trap ping carbon dioxide to cool the Earth's warming atmosphere.