Sequestration

From the March 2013 EcoNet News:

Sequestration is the capture and long-term storage of atmospheric carbon dioxide, CO2 removal, an important form of geo-engineering. There are several forms of sequestration: oceanic, geologic, and terrestrial. Sequestration occurs above ground in leaves, stems and trunks of trees; in long-lived products such as wood to make houses; and in soil - northern forests store twice the carbon in the soil as they do above ground; and in rocks that tie up carbon for years.

Bio-sequestration is about natural processes. Then there's "carbon capture and storage," stripping CO2 from flues of power plants and industries and then injecting it into salt caverns and other underground repositories. A coal plant in North Dakota became the nation's first to capture carbon emissions from flue gases in 2000. The oil industry has been injecting CO2 in wells for enhanced oil recovery for years.

Let's get back to basics. There's a lot of sequestration taking place without fanfare every day. Geologic sequestration is the least obvious, where CO2 is stored in the pores of geologic formations. Even it can be manipulated through hydrodynamic, solubility, and mineral carbonation "trapping." Oceans are the biggest CO2 sinks. Then there's terrestrial sequestration, when carbon is stored in plants, animals, and soils. Imagine peat bogs. To be effective biomass sinks, trees and forests must grow in perpetuity.

Every year, American trees capture an enormous amount of CO2, one estimate is 310 million metric tons of carbon dioxide each year. Others say 200 - 300 million tonnes annually. That's about 5% of the national footprint. While the value is imprecise, forests certainly provide an "enormous ecosystem service."

Note that a small percentage of this "sink" is lost annually. Every year, about 0.9% of American forests burn in forest fires. The year 2006 was unusually bad, 1.3% of the forest cover burned.