1 Carbon sequestration is the fixation of atmospheric carbon dioxide in a carbon sink through biological or physical processes.

2 Energy Information Administration, Emissions of Greenhouse Gases in the United States 2005, DOE/EIA-0573(2005) (Washington, DC, November 2006), web site www.eia.doe.gov/oiaf/1605/ggrpt.

3 Based on total emissions from Energy Information Administration, Emissions of Greenhouse Gases in the United States 2005, DOE/EIA-0573(2005) (Washington, DC, November 2006), web site www.eia.doe.gov/oiaf/1605/ggrpt.

4 The total number of projects reported for 2004 has increased from 2,154 to 2,185 with the receipt of 6 additional reports after the database used to prepare the annual report and Public Use Database for 2004 was finalized. See note to Table S1.

5 Energy Information Administration, Voluntary Reporting of Greenhouse Gases 2004: Summary, DOE/EIA-0608(2004/S) (Washington, DC, March 2006), p. 10, web site www.eia.doe.gov/oiaf/1605/vr04data/summary/.

6 Twenty-seven electric utilities submitted reports on 10 ongoing UtiliTree Carbon Company projects. Twenty-three electric utilities, including 13 UtiliTree participants, submitted reports on 3 new PowerTree Carbon Company projects.

7 Formal commitments in one or more of the entity-level, project-level, or financial categories accommodated by Form EIA-1605 were reported by 76 companies. Descriptions of future activities were provided by 10 companies in the Additional Information section of Schedule IV.

8 Federal Register, Vol. 71, No. 77 (April 21, 2006), p. 20784.

9 Federal Register, Vol. 71, No. 144 (July 27, 2006), p. 42637.

10 Federal Register, Vol. 71, No. 217 (November 9, 2006), p. 65786.