for National Geographic News
The ocean floor could provide storage for more excess carbon dioxide than the world can ever produce, scientists say.
A team of researchers proposes disposing of the carbon dioxide produced from burning fossil fuels by injecting it into seabed sediments nearly two miles (three and a quarter kilometers) below the ocean's surface.
There the combination of cold temperatures and extreme pressure will trap the gas for millions of years, says the study's lead author, Kurt Zenz House, a graduate student in geoscience at Harvard University in Cambridge, Massachusetts.
House's team published its proposal last week in the Proceedings of the National Academy of Sciences.
The accumulation of carbon dioxide (CO2) in the atmosphere from fossil fuel use is believed to be a leading contributor to global warming.
(See National Geographic magazine's "Global Warning: Signs From Earth.")
One way to reduce global warming without drastic reductions in energy consumption is by removing carbon dioxide from power-plant emissions and putting it where it cannot enter the atmosphere.
In the past scientists have proposed storing CO2 in geologic formations such as depleted natural gas fields.
(Read related story: "Clean Coal? New Technology Buries Greenhouse Emissions" [May 2006].)
"Those storage options make sense and can be used to large degree," House said.
But they don't eliminate the possibility that the gas could make its way back to the surface, he adds.
"If it can find a conduit through a well or a fault, it has the potential to escape," House said.
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