Posted on 04/16/2004 5:29:53 AM PDT by ckilmer
Moss Landing researchers reveal iron as key to climate change
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PRESS RELEASE APRIL 15, 2004
EMBARGOED: Not for release until Thursday, 15 April 2004 at 14:00 Eastern Time
MOSS LANDING RESEARCHERS REVEAL IRON AS KEY TO CLIMATE CHANGE
MOSS LANDING, California - A remarkable expedition to the waters of Antarctica reveals that iron supply to the Southern Ocean may have controlled Earth's climate during past ice ages. A multi-institutional group of scientists, led by Dr. Kenneth Coale of Moss Landing Marine Laboratories (MLML) and Dr. Ken Johnson of the Monterey Bay Aquarium Research Institute (MBARI), fertilized two key areas of the Southern Ocean with trace amounts of iron. Their goal was to observe the growth and fate of microscopic marine plants (phytoplankton) under iron-enriched conditions, which are thought to have occurred in the Southern Ocean during past ice ages. They report the results of these important field experiments (known as SOFeX, for Southern Ocean Iron Enrichment Experiments) in the April 16, 2004 issue of Science.
Previous studies have suggested that during the last four ice ages, the Southern Ocean had large phytoplankton populations and received large amounts of iron-rich dust, possibly blown out to sea from expanding desert areas. In order to simulate such ice-age conditions, the SOFeX scientists added iron to surface waters in two square patches, each 15 kilometers on a side, so that concentrations of this micronutrient reached about 50 parts per trillion. This concentration, though low by terrestrial standards, represented a 100-fold increase over ambient conditions, and triggered massive phytoplankton blooms at both locations. These blooms covered thousands of square kilometers, and were visible in satellite images of the area.
Each of these blooms consumed over 30,000 tons of carbon dioxide, an important greenhouse gas. Of particular interest to the scientists was whether this carbon dioxide would be returned to the atmosphere or would sink into deep waters as the phytoplankton died or were consumed by grazers. Observations by Dr. Ken Buesseler of Woods Hole Oceanographic Institution and Dr. Jim Bishop of Lawrence Berkeley National Laboratories (reported separately in the same issue of Science) indicate that much of the carbon sank to hundreds of meters below the surface. When extrapolated over large portions of the Southern Ocean, this finding suggests that iron fertilization could cause billions of tons of carbon to be removed from the atmosphere each year. Removal of this much carbon dioxide from the atmosphere could have helped cool the Earth during ice ages. Similarly, it has been suggested that humans might be able to slow global warming by removing carbon dioxide from the atmosphere through a massive ocean fertilization program.
Unlike previous iron fertilization experiments, SOFeX focused on the two different parts of the Southern Ocean to determine if the iron-induced blooms would be influenced by variations in silicic acid concentrations. Silicic acid is essential to the growth of diatoms, a common type of phytoplankton. The southern part of the Southern Ocean typically has an abundance of silicic acid but the northern part often has very low levels. The results of this experiment indicate that even where silicic acid levels are low, iron fertilization can result in blooms of phytoplankton such as dinoflagellates and prymneseophytes, which do not require silicon for growth yet still consume vast amounts of carbon dioxide. This finding has doubled the area of the Southern Ocean that scientists believe could be important for carbon cycling.
The SOFeX experiment was carried out during January and February of 2002, after a decade of planning and preparation, and was funded by the US National Science Foundation and the US Department of Energy. It involved two US research vessels from Scripps Institution of Oceanography and one US Coast Guard research ice-breaker, as well as about 100 scientists from at least eighteen different research institutions. This important experiment is covered in three research articles in the April 16 issue of Science, and is featured on the magazine’s cover.
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Research article citation: Kenneth H. Coale, et al. Southern ocean iron enrichment experiment: carbon cycling in high-and low-Si waters. Science. Vol. 304 #5669 (April 16, 2004).
Media contacts: Dr. Kenneth Coale, Moss Landing Marine Laboratories (831) 771-4406 coale@mlml.calstate.edu
Kim Fulton-Bennett, Communications Associate, Monterey Bay Aquarium Research Institute, (831) 775-1835 kfb@mbari.org
SOFEX Cruise log and background information is available at: http://www.mbari.org/expeditions/SOFeX2002/
I'm a little skeptical, but it sure is interesting!
It has to be dissolved in an acidic solution or it will precipitate out as ferric hydroxide at the normal surface pH of seawater.
Though he didn't think about the climatic effects, Arthur C. Clarke beat you to it by a couple of decades in The Deep Range. Not with sewer sludge, but he proposed fertilization and phytoplankton farming to feed the whales... (and there's more to it if you haven't ever read it. Though dated, it's still surprisingly prescient.
I'm not sure if the Pacific Gyre would work as well as the Southern Ocean. The Southern Ocean has plenty of nitrate and phosphate, but not enough iron, which is why iron fertilization works there. The Pacific Gyre doesn't have any upwelling, so it doesn't have nitrate, phosphate or iron (it's a long way from any continents in the mid-Pacific). Though sewer sludge would provide some nitrate and phosphate, and you could enrich it with a little bit of iron, the vast size of that oceanic region means that the scale of the amount you'd have to ship out there is really large.
I agree. These grant funded social scientists are playing at changing the climate to suit the political fashion of the day.
I have no doubt that the Earth will recover from any Woops! they create, but mankind might not survive to record the empirical datum.
I made the proposal specifically to sequester carbon in calcium carbonate as a sophomore taking college chemistry and oceanology (a great course).
It was an obvious thing to do.
Though sewer sludge would provide some nitrate and phosphate, and you could enrich it with a little bit of iron, the vast size of that oceanic region means that the scale of the amount you'd have to ship out there is really large.
We make a lot of sludge near coastal cities and are looking for better things to do with it. I'd bet there's a fair amount of iron in it as well as trace minerals that we probably don't know about. The transportation by water would be cheaper than we now use by land and in most cases the sludge could be piped instead of burning methane to dry it. I like the containment aspects of the gyre. The stuff goes straight down.
I do habitat restoration on my land. I don't share your optimism. These eco-monsters are that destructive. Note Post #5 on the thread.
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