April 13, 2009 -- An ambitious plan to slow global warming by locking CO2 deep in the ocean has hit a stumbling block, according to a new study that shows the geoengineering technique is not as effective as scientists had previously hoped. "The amount of carbon dioxide that could be taken up is less than we assumed," said Victor Smetacek, a scientist at Alfred Wegener Institute who co-led the expedition. Don't discount ocean fertilization yet however, say scientists working both inside and outside the research study. "With other climate change initiatives, ocean fertilization could still play a role in reducing climate change," said Smetacek. The idea behind ocean fertilization is a simple one. Carbon dioxide is slowly raising the average temperature of the Earth. If some of the carbon dioxide in the atmosphere could be removed the Earth wouldn't heat up as fast. Scientists have come up with a wide variety of plans to remove CO2 from the atmosphere. Some scientists want to pump C02 deep into the underground. Others want to use carbon nanotubes to turn CO2 into methane or other compounds. Related Content:
Smetacek and his colleagues want to lock up the excess carbon dioxide inside the world's oceans, or more specifically, inside the bodies of microscopic creatures known as plankton, that would die and fall to the bottom of the ocean. A certain class of plankton, known as phytoplankton, already remove carbon dioxide from the atmosphere through photosynthesis. If there were more phytoplankton, the German and Indian scientists reasoned, then the microscopic creatures would lock away more carbon dioxide. Phytoplankton need iron to grow. In the open ocean usable iron is difficult to come by, so adding iron to the ocean would lead to more phytoplankton. Over the course of two and a half months the team of scientists "administered," as Smetacek says, more than six tons of dissolved iron (the kind found in most home improvement stores) over a 300-square-kilometer (116-square-mile) patch of the southwest Atlantic. The additional iron certainly encouraged more phytoplankton. The amount of biomass in the test area doubled, which scientists determined during marathon 36 hour sampling sessions. The scientists created more plankton, but the plankton didn't perform as the scientists had hoped. Instead of dying and sinking to the bottom of the ocean, the additional plankton were eaten, first by copepods, then by ampipods. As the carbon moved up the food chain some of was released back into the atmosphere as carbon dioxide. Get More NewsMouse Cloned From Long-Frozen CellResearchers create a mouse from a long-frozen cell. Will the mammoth be next?'Bubble' Could Protect AstronautsScientists say a "bubble" around a Mars-bound spaceship could protect astronauts.Big Reduction of Snowmobiles in Yellowstone ProposedA new plan would cut snowmobile use by 40 percent in Yellowstone.Microbes: Fuel of the Future?A reddish South American microbe is literally breathing fuel, say scientists.DNA Links Remains to Steve FossetDNA tests on two bones found in California confirm they are those of Steve Fossett.Women Carry More Bacteria Than MenSome bacteria prefer women, suggests a new study. But why?Ancient 'Water Monster' Facing ExtinctionA foot-long salamander that was a key part of Aztec legend is threatened by extinction.Grand Canyon's Youth ConfirmedThe Grand Canyon is millions of years younger than previously thought, argue geologists.My Take: E-Voting Not User FriendlyOpinion: Electronic voting machines don't always capture the intent of voters.SLIDE SHOW: Landscapes of TerrorWhat makes a place feel scary? There are scientific explanations.At 40, Brain and Body SlowThe part of the brain in charge of motion starts a gradual slide in middle age.Spiders, Scorpions Among World's Oldest CreaturesMany creepy crawlies have been on Earth much longer than previously believed.Blood-Sucking Vampire Bats Sing DuetsWhite-winged vampire bats "harmonize" with separated roost mates. |
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