Ocean fertilization yields hope, uncertainty for global
sulfate mixed with ocean water produces phytoplankton,
which draw carbon dioxide from the atmosphere
(CNN) -- Scientists are trying to determine whether treating
ocean water with iron sulfate is a quick fix for global warming or a
Pandora's Box that could lead to further environmental problems.
Scientists and entrepreneurs alike see opportunity in the results
of a mid-1990s experiment in which Moss Landing Marine Laboratories
spread relatively small amounts of iron sulfate across a
100-square-mile patch of ocean.
"By day four, five, the oceans had turned green," said Kenneth
Coale, oceanographer and acting director of Moss Landing Marine
Laboratory. "(It) had turned from what is an electric blue,
characterizing the equatorial Pacific, to something bright green.
You could smell the difference."
Increased plant biomass, production
The iron-treated ocean rapidly produced tiny ocean plants called
phytoplankton that draw carbon dioxide, a greenhouse gas associated
with global warming, from the atmosphere. Coale estimates the
experiment increased plant biomass by a factor of almost 40 and
plant production by a factor of five or six.
"In nine days, we had grown thousands of tons of phytoplankton
and biomass and drawn down atmosphere carbon dioxide," he said.
Lab director John Martin originally proposed the experiment. He
was widely quoted as saying, "Give me a half tanker of iron, and
I'll create an ice age,".
But Martin died before getting to test his theory of whether
organisms feeding on that much phytoplankton could rob the ocean of
oxygen and in turn, kill fish.
As the U.S. Department of Energy monitors the experiments, it
hypothesizes that carbon may be locked up and sent to the bottom of
the ocean or re-released back into the atmosphere.
"We can turn the ocean green, but we really don't have a clue as
to where the carbon goes," said Jim Bishop of the Department of
Until they figure that out, researchers say it may be risky to
try to turn down the global thermostat by turning up phytoplankton
Coale's group will return to the ocean for another
100-square-mile iron fertilization experiment in about a year.
"We need to understand whether this is the way that nature turned
on and off global warming in the past, and we need experiments of a
relatively large scale in order to answer those questions," Coale
A potential billion dollar market
Also taking to the waters is Greensea Venture Inc. and chemical
engineer Michael Markels, who will spread his proprietary mixture of
chelated iron over 5,000 square miles of ocean in a $7 million
Markels said he's interested as much in product development as
academic research, but at stake is a potential market worth billions
of dollars in "credits" for carbon dioxide-producing industries.
Industry pays from $30 to $100 to rid its exhaust gases of carbon
dioxide, but Markels believes the greenhouse gas can be removed for
about $2 a ton by treating the oceans with iron.
"We've thought coal companies might be interested in this because
they could sort of have a little license attached to their coal that
says, when you burn this coal, no net CO2 would go into the
atmosphere because we've already taken it out," Markels said.
Markels said he'll ask academic researchers, including Moss
Landing Marine Laboratories, to participate in the evaluation of his
experiment, but Coale may be leery of Markels' approach to global
"Iron fertilization for geo-engineering, or fish production, has
been driven by a kind of quick-buck philosophy that is not
necessarily sensitive to downstream effects," he said.
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U.S. Department of Energy
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