The
Geritol solution is the name given to one of the possible
direct action methods for reducing the amount of carbon dioxide
in the atmosphere, and thus slowing down or reversing
global warming.
The oceans are a great natural sink of greenhouse gases. It has
been estimated that they absorb 40% of fossil fuel emissions. The
key to this is the plankton processing vast stores of gases, how
much is unclear. It is known that during the ice ages, carbon dioxide
levels dropped 30%.
The question is how can this be done today. In theory, lowering
carbon dioxide levels should lower temperatures.
Give me half a tanker full of iron, and I'll give you another ice age.
--John Martin (Moss Landing Marine Laboratory, California)
In the polar regions there are huge reserves of nitrates and
phosphates that phytoplankton thrive on. The only thing lacking
is iron.
First proposed by Martin in 1998, the Geritol solution would be to
seed these oceans with iron dust which then dissolves into the water.
It is possible that this is what caused the ice ages: as the land dried
more dust blew into the oceans fostering growth of plankton.
In 1996 the idea was tested by the U.S. government. Near the
Galapagos Islands exists a fairly biologically barren area.
Over a 28 square mile area of blue sea, scientists poured 990
pounds if iron during a week of testing. The waters immediately
bloomed green with phytoplankton. At its height, it covered 200
square miles. One thousand pounds of iron dust stimulated over
2000x its own weight in plant growth - much greater than any land
fertilizer. The plankton itself soaked up carbon dioxide, reducing
the concentration in nearby sea water by 15%. This deficiency in
the sea water was quickly made up by drawing carbon dioxide from
the air.
If carried out in a full scale, this would only affect 16% of
the ocean area. Estimates place it at reducing atmospheric
carbon dioxide levels from 6% to 21%.
Its primary advantages are that it is low tech, and simple to
stop. Its not hard to dump millions of tons of iron dust
into the ocean. If you stop feeding the plankton, the
current crop will die.
Questions remain about how much of the carbon dioxide actually
gets deeply buried and how this would affect the food chain.