Concerns over climate change are promoting the development of carbon management strategies. Since 1751, the beginning of the industrial revolution, fossil fuel burning has released more than 277 billion tons of carbon to the atmosphere. The combustion of coal, oil and natural gas generates annual carbon emissions of 6 billion tons. This has increased atmospheric carbon dioxide concentrations from 320 parts per million (ppm) in 1957 to 370 ppm today, a 31% increase. Analyzed bubbles of fossilized air trapped in ice cores show that our current atmospheric carbon dioxide (CO2) concentration is at its highest point in 420,000 years - and possibly in the last 20 million years (Dunn, 2001).
President Bush's Global Climate Change Initiative (GCCI) commits the United States to an aggressive strategy to reduce greenhouse gas (GHG) intensity by 18% over the next 10 years. By focusing on greenhouse gas intensity (the ratio of greenhouse gas emissions to economic output) as the measure of success, this strategy promotes vital climate change R&D, while minimizing the economic impact of greenhouse gas stabilization on the United States. This goal can be accomplished using a three-pronged approach as follows: (1) Making energy systems more efficient; (2) Increasing the use of low carbon fuels; and (3) Capture, sequestration and mitigation of greenhouse gases. In support of this third approach, the United States' Department of Energy (DOE) established a Carbon Sequestration Program in 1998 (DOE, 2004).
Carbon sequestration options include geologic, terrestrial and ocean sequestration. Geologic sequestration options include direct injection into geological formations, including coal seams that cannot be mined, saline aquifers and depleted oil and gas reservoirs. Terrestrial sequestration is aimed at enhancing the uptake of carbon dioxide from domestic terrestrial ecosystems. Ocean sequestration includes both injection into deep areas of the ocean and increased stimulation of ocean surface waters to grow phytoplankton and take up carbon dioxide.
Source: National Energy Technology Laboratory, Department of Energy
