Scientists enhance Mother Nature's carbon handling mechanismNovember 07, 2007Taking a page from Nature herself, a team of researchers developed a method to enhance removal of carbon dioxide from the atmosphere and place it in the Earth's oceans for storage. Unlike other proposed ocean sequestration processes, the new technology does not make the oceans more acid and may be beneficial to coral reefs. The process is a manipulation of the natural weathering of volcanic silicate rocks. Reporting in today's (Nov. 7) issue of Environmental Science and Technology, the Harvard and Penn State team explained their method. "The technology involves selectively removing acid from the ocean in a way that might enable us to turn back the clock on global warming," says Kurt Zenz House, graduate student in Earth and planetary sciences, Harvard University. "Essentially, our technology dramatically accelerates a cleaning process that Nature herself uses for greenhouse gas accumulation."
In natural silicate weathering, carbon dioxide from the atmosphere dissolves in fresh water and forms weak carbonic acid. As the water percolates through the soil and rocks, the carbonic acid converts to a solution of alkaline carbonate salts. This water eventually flows into the ocean and increases its alkalinity. An alkaline ocean can hold dissolved carbon, while an acidic one will release the carbon back into the atmosphere. The more weathering, the more carbon is transferred to the ocean where some of it eventually becomes part of the sea bottom sediments. "In the engineered weathering process we have found a way to swap the weak carbonic acid with a much stronger one (hydrochloric acid) and thus accelerate the pace to industrial rates," says House. The researchers minimize the potential for environmental problems by combining the acid removal with silicate rock weathering mimicking the natural process. The more alkaline ocean can store carbon as bicarbonate, the most plentiful and innocuous form of carbon in the oceans. According to House, this would allow removal of excess carbon dioxide from the atmosphere in a matter of decades rather than millennia. Besides removing the greenhouse gas carbon dioxide from the atmosphere, this technique would counteract the continuing acidification of the oceans that threatens coral reefs and their biological communities. The technique is adaptable to operation in remote areas on geothermal or natural gas and is global rather than local. Unlike carbon dioxide scrubbers on power plants, the process can as easily remove naturally generated carbon dioxide as that produced from burning fossil fuel for power. The researchers, Kurt House; Daniel P. Schrag, director, Harvard University Center for the Environment and professor of Earth and planetary sciences; Michael J. Aziz, the Gordon McKay professor of material sciences, all at Harvard University and Kurt House's brother, Christopher H. House, associate professor of geosciences, Penn State, caution that while they believe their scheme for reducing global warming is achievable, implementation would be ambitious, costly and would carry some environmental risks that require further study. The process would involve building dozens of facilities similar to large chlorine gas industrial plants, on volcanic rock coasts. "This work shows how we can remove carbon dioxide on relevant timescales, but more work is be needed to bring down the cost and minimize other environmental effects," says Christopher H. House. Penn State | |||||||||||||||||||||
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Related Carbon Dioxide News Articles Scientists peel away the mystery behind gold's catalytic prowess Few materials have exercised as much of a hold on the human imagination, or on human history, as has gold. Bad sign for global warming: Thawing permafrost holds vast carbon pool Permafrost blanketing the northern hemisphere contains more than twice the amount of carbon in the atmosphere, making it a potentially mammoth contributor to global climate change depending on how quickly it thaws. Complex ocean behavior studied with 'artificial upwelling' A team of scientists is studying the complex ocean upwelling process by mimicking nature - pumping cold, nutrient-rich water from deep within the Pacific Ocean and releasing it into surface waters near Hawaii that lack the nitrogen and phosphorous necessary to support high biological production. Thawing permafrost likely to boost global warming The thawing of permafrost in northern latitudes, which greatly increases microbial decomposition of carbon compounds in soil, will dominate other effects of warming in the region and could become a major force promoting the release of carbon dioxide and thus further warming, according to a new assessment in the September 2008 issue of BioScience. No more big stink: Scent lures mosquitoes, but humans can't smell it Mosquito traps that reek like latrines may be no more. A University of California, Davis research team led by chemical ecologist Walter Leal has discovered a low-cost, easy-to-prepare attractant that lures blood-fed mosquitoes without making humans hold their noses. Smoking during pregnancy a 'double-edged sword' in SIDS Premature infants whose mothers smoked during pregnancy may be at even higher risk for sudden infant death syndrome (SIDS) than preemies whose mothers did not smoke, according to new research out of the University of Calgary. Why is Greenland covered in ice? There have been many reports in the media about the effects of global warming on the Greenland ice-sheet, but there is still great uncertainty as to why there is an ice-sheet there at all. DOE official cites need for major breakthroughs to cope with climate change Meeting the world's growing energy needs while responding to global warming during the 21st Century will be one of the biggest challenges humanity has ever faced, Raymond L. Orbach, Ph.D., the U.S. Department of Energy's Under Secretary for Science, says in the latest podcast in the American Chemical Society's Global Challenges/Chemistry Solutions series Future for clean energy lies in 'big bang' of evolution Amid mounting agreement that future clean, "carbon-neutral", energy will rely on efficient conversion of the sun's light energy into fuels and electric power, attention is focusing on one of the most ancient groups of organism, the cyanobacteria. Groundbreaking research shows DEET's not sweet to mosquitoes Spray yourself with a DEET-based insect repellent and the mosquitoes will leave you alone. But why? They flee because of their intense dislike for the smell of the chemical repellent and not because DEET jams their sense of smell, report researchers at the University of California, Davis. More Carbon Dioxide News Articles |
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