Tierramérica: The German oceanography ship Polarstern, one of the most prestigious in the world, is conducting a major experiment of dispersing iron in seawater in order to absorb carbon dioxide, the principal climate changing gas. The experiment, under way to the northeast of the South Georgia Islands in the southern Atlantic, is intended to promote the growth of phytoplankton and consequent absorption of carbon by dumping 20 tons of iron sulfate over an area of 300 square kilometers. The …