April 1, 2009

CO2 Emissions Absorbed By Underground Water

Researchers said on Wednesday that water deep below ground has safely trapped carbon dioxide for millions of years and may one day help absorb emissions of the greenhouse gas to help slow climate change, Reuters reported.

Chris Ballentine, a researcher at the University of Manchester, who worked on the study, said the finding shows that such carbon capture and storage is possible provided scientists find an area where the geology is suitable.

Therefore, researchers can locate ancient deep water systems miles below the surface to ensure gas doesn't escape back into the atmosphere.

"Clearly we want to bury carbon dioxide in the ground, that is a no-brainer," Ballentine said.

However, he questioned how safe it would be to put carbon dioxide into the ground.

Climate scientists have warned that elevated levels of greenhouse gases emissions like CO2 will lead to higher temperatures, rising seas, drought, and cause floods, heat waves and stronger storms.

Carbon capture and storage could aid governments in the fight against global warming because it captures the emissions from fossil fuel burning power stations and buries them underground.

Experts say the process could keep up to a third of all carbon emissions out of the atmosphere.

But on a commercial scale, the technology is untried and will initially cost over a billion dollars per power plant, creating difficulties for companies to undertake it without support.

China is already opening one coal-fired power plant a week, creating global reserves of coal that could last hundreds of years.

The new report studied how carbon dioxide dissolved into water as well as another technique to see if it reacted with the rocks at nine natural gas fields in North America, China and Europe filled with the greenhouse gas after volcanic eruptions thousands or millions of years ago.

The researchers said water underground was found to be the major carbon sink in these gas fields and had been for millions of years, which could be used to store large amounts of greenhouse gas in the future.

Studies in the past have shown that certain rocks below the surface soak up carbon, but those published in the journal Nature suggested that most rocks do not store the greenhouse gas and the water instead keeps it safe.

Stuart Gilfillan, a researcher at the University of Edinburgh, who worked on the study, said in a statement: "By combining two techniques, we've been able to identify exactly where the carbon dioxide is being stored for the first time."

He believes the new study clearly demonstrates how the carbon dioxide has been stored naturally and safely in underground water in these fields.


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