Seeding the seas?

Sprinkling powdered iron into the ocean may help reduce atmospheric carbon dioxide

Published: Friday 31 October 1997

-- (Credit: Sanjay ghosh)deficiency of iron in the microscopic plant-like organisms that populate the seas - called phytoplankton - may have interfered in the carbon dioxide cycle and contributed to global warming. Scientists are now investigating reversal of this process. Confirmation of this fact will provide answers that may help combat global warming.

Recent research has shown that the iron content of sea water has gonedown considerably, leading to death of marine plants, including phytoplankton, which absorb carbon dioxide (co2) from the atmosphere. It is known that iron plays a crucial role in plant meta-bolism, especially photosynthesis, whereby plants produce food with the help of light and co2 from the atmosphere (The Smithsonian , Vol 28, No 2).

Iron particles carried by rivers, are washed into the seas.But dams and other barriers on rivers have reduced this source, resulting in lack of iron in coastal areas. This is a major factor responsible for 'withered seashores' - areas in which marine plants have withered and died.

The answer to the problem may well be to sprinkle powdered iron into the sea to facilitate photosynthesis and allow plants to regenerate. The idea was first suggested by John Martin and Steve Fitzwater of Moss Landing Marine Laboratories in California, usa , in 1988.

They said that the Antarctic Ocean should be seeded with powdered iron to stimulate growth of phytoplankton, which would spread over the surface area of the ocean. Although this might be a costly proposition and appear impractical, the researchers have supported the suggestion with the hypothesis that increased growth of phytoplankton would help absorb excess co2 in the atmosphere, which plays a major part in global warming.

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