Carbon dioxide emissions – largely due to fossil fuel combustion – are at the crux of the global warming problem. Because some carbon dioxide emissions are fairly localized, they are potentially easy to control.
Consider coal-fired power plants. In the U.S., they account for about 40% of the annual emissions of carbon dioxide from all human activities. Most power plants are large, and the emissions come out of a smokestack. Capturing those emissions could reduce negative impacts on our atmosphere.
Carbon capture and storage technology envisions just that. Capture the emissions and pump them underground, where they can be stored deep in the Earth. In some cases the carbon dioxide would react with the underlying rocks, so that it would be unlikely to leak back to the surface. In other cases, captured carbon would dissolve in groundwater or be retained in the pore space of the rocks.
Recently, the U.S. Geological Survey assessed 36 of the country’s potential carbon storage basins. Using current technology, it’s estimated that nearly 3000 gigatons of carbon dioxide could potentially be stored underground. This is more than 500 times the amount of CO2 that was emitted from fossil fuels in the U.S. last year.
Of course, carbon capture and storage is not without its drawbacks. It takes energy to pump gas into rock, and we need to make sure that it will stay there and not leak back to the surface. But, at least the proponents of carbon capture and storage know that there is a large potential storage capacity out there.
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Web Links
The Gigaton Question: How Much Geologic Carbon Storage Potential Does the United States Have?
Photo, taken on April 17, 2006, courtesy of U.S. Embassy Canada via Flickr.
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Earth Wise is a production of WAMC Northeast Public Radio. Support for Earth Wise comes from the Cary Institute of Ecosystem Studies in Millbrook, NY.