What is carbon sequestration?

Like much of nature, carbon cycles through earth's geological and biological systems. 

• Biological carbon cycling can be very fast, cycling within a growing season or a few years.
• Geological cycling is much longer, typically hundreds of thousands to millions of years. 
   

Captioning carbon

Coal, oil, and gas release carbon that has been stored underground hundreds of millions of years. The additional carbon goes into the atmosphere as carbon dioxide, which is a greenhouse gas. To counter this, new processes store, or sequester, carbon. These methods may be for periods of years or millions of years.

• Soil sequestration: A short-term example of carbon sequestration is soil sequestration. By allowing organic matter to build up in soil, the carbon is stored as long as the organic matter is in place. Since newly formed organic matter decomposed easily with any soil disturbance, this solution is short-term.
   
• Tree sequestration: Planting trees offers a longer-term solution. Trees stores carbon in the wood.  Once a tree dies, the wood decomposes and releases carbon dioxide into the atmosphere. This type of storage will be in the decades range.
   
• Rock injection sequestration: Injecting carbon dioxide into porous deep rock formations offers a  very long-term sequestration option without allowing it to travel far from the injection site. It's essential layers of rock above the injection rock will not allow upward migration of the carbon dioxide. This type of storage would allow for millions of years range, but only a few geological locations are feasible.

All methods of storage have benefits and disadvantages. No one method is ideal, and research continues to examine ways to carbon sequestration that is long-lasting  cost effective, and environmentally sound.