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 Current Events and Carbon Dioxide News Articles Chemists describe solar energy progress and challenges, including the 'artificial leaf' Scientists are making progress toward development of an "artificial leaf" that mimics a real leaf's chemical magic with photosynthesis - but instead converts sunlight and water into a liquid fuel such as methanol for cars and trucks. Texas A&M prof to predict weather on Mars Is there such a thing as "weather" on Mars? There are some doubts, considering the planet's atmosphere is only 1 percent as dense as that of the Earth. Report on US-China collaboration on carbon capture and sequestration Lawrence Livermore National Laboratory's Julio Friedmann, in collaboration with the Center for American Progress, the Asia Society Center and with partner Monitor Group, today released the report, "A Roadmap for U.S.-China Collaboration on Carbon Capture and Sequestration." Study gives clearer picture of how land-use changes affect U.S. climate Researchers say regional surface temperatures can be affected by land use, suggesting that local and regional strategies, such as creating green spaces and buffer zones in and around urban areas, could be a tool in addressing climate change. Laser etching safe alternative for labeling grapefruit Laser labeling of fruit and vegetables is a new, patented technology in which a low-energy carbon dioxide laser beam is used to label, or "etch" information on produce, thereby eliminating the need for common sticker-type labels. Iron controls patterns of nitrogen fixation in the Atlantic Scientists including researchers from the National Oceanography Centre, Southampton and the University of Essex have discovered that interactions between iron supply, transported through the atmosphere from deserts, and large-scale oceanic circulation control the availability of a crucial nutrient, nitrogen, in the Atlantic. North America automobile sector bottom of 'world sustainability league' The study, entitled Sustainable Value in Automobile Manufacturing, looks at the sustainability performance of 17 leading car manufacturers worldwide between 1999 and 2007. Interactions with aerosols boost warming potential of some gases For decades, climate scientists have worked to identify and measure key substances -- notably greenhouse gases and aerosol particles -- that affect Earth's climate. Volcanoes played pivotal role in ancient ice age, mass extinction Researchers here have discovered the pivotal role that volcanoes played in a deadly ice age 450 million years ago. Perhaps ironically, these volcanoes first caused global warming -- by releasing massive amounts of carbon dioxide into the atmosphere. When they stopped erupting, Earth's climate was thrown off balance, and the ice age began. Ocean acidification may contribute to global shellfish decline Relatively minor increases in ocean acidity brought about by high levels of carbon dioxide have significant detrimental effects on the growth, development, and survival of hard clams, bay scallops, and Eastern oysters, according to researchers at Stony Brook University's School of Marine and Atmospheric Sciences. More Carbon Dioxide Current Events and Carbon Dioxide News Articles |
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