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Wednesday, Dec. 6
The Indiana Daily Student


Researchers test geofertilizing

Results of a large-scale experiment in the Southern Ocean, which surrounds Antarctica, hint that scientists could engineer the world's oceans, according to Nature. But some experts say the effects of "geofertilizing" can be harmful.\nThe procedure can be accomplished by stimulating the growth of algae, which consume carbon dioxide. This means oceans can then be immense sponges for carbon dioxide -- the culprit for rising global temperatures.\nPhilip Boyd and his colleagues from the New Zealand National Institute of Water and Atmospheric Research (NIWA), were part of the Southern Ocean Iron Release Experiment (SOIREE), an international collaboration, which was conducted last year. Researchers released more than eight and a half thousand kilograms of an iron compound into the Southern Ocean within an area of eight kilometers across and monitored its effect on the growth of marine plants or phytoplanktons.\n"Iron, normally, is a limiting nutrient," said associate biology professor Flynn Picardal. "Just like the human body needs iron for hemoglobin, planktons use them to make certain enzymes and co-factors. But because of its low concentrations, it tends to limit the growth of planktons. Therefore, when iron is broadcast over an ocean it stimulates an increase in plankton growth."\nMassachusetts Institute of Technology Professor Sallie D. Chisolm said while phytoplanktons on the surface of the ocean absorb carbon dioxide directly from the atmosphere, deeper biomass function differently. They draw on the carbon dioxide dissolved in the ocean. The phytoplanktons then convert the carbon dioxide into carbohydrates during photosynthesis, she said. \nBen Brabson, environmental physicist and physics professor, addressed concerns on how the ocean's behavior as a large reservoir of carbon, affects the carbon dioxide in the atmosphere. He said the carbon dioxide levels in the ocean and atmosphere are related.\n"In pre-industrial times, the carbon dioxide in the atmosphere and the ocean were roughly the same," Brabson said. "Since then, the ocean has continued to absorb dioxide from the atmosphere and now contains 40 times more carbon dioxide than the atmosphere."\n"The researchers are attempting to spur plankton growth, so that more carbon dioxide from the ocean can be used in photosynthesis. The dioxide level having now decreased, the scientists predict the ocean will now absorb more carbon dioxide from the atmosphere and thereby reduce warming."\nSo while the scientists relied on the deeper bio-mass to decrease ocean levels of carbon dioxide and thereby alter the atmospheric levels, the effects of the planktons on the surface water were seen immediately. According to Boyd in Nature, "Increased iron supply led to elevated phytoplankton biomass (levels) and rates of photosynthesis in surface water, causing a large draw down of carbon dioxide." \nThis is not the first time that this procedure has been tested. According to the results reported in Nature in 1996, a team of scientists conducted an experiment similar to SOIREE in the equatorial Pacific Ocean. And, indeed the phytoplankton 'bloomed' in response to hundreds of kilograms of an iron compound. \nBut this kind of geofertilizing can be potentially very dangerous, Chisolm said.\n"While iron increases the plankton bio-mass, considering it as a possibility to reduce greenhouse gases is short-sighted. There can be other ramifications. Other greenhouse gases can be stimulated and the toxicity levels can increase dramatically, adversely affecting the ocean habitat.\n"I think this is very exciting science, and we should continue experimenting like this, but the simultaneous effects on the waters should also be kept in mind," she said.\nEchoing similar sentiments, Brabson added, "I think it's a great effort in the right direction, but it may be something that will hold good only in warmer tropical waters, not in the Northern oceans. It seems slightly hair-brained and a rather long shot."\nThis may be considered by some as sidestepping the real solutions to global warming. "I don't think this is an effective way to combat warming. Developing more efficient fuels, and more renewable sources of energy are more viable options," Chisholm said.

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