Release Date: January 2008 Next Release Date: January 2009 State…

Release Date: January 2008
Next Release Date: January 2009



State Energy-related Carbon Dioxide Emissions Estimates

Although energy-related carbon dioxide (CO2) emissions do not encompass a full
greenhouse gas inventory, the state energy-related carbon dioxide emissions do give a
good indicator of the relative importance of individual states to the national greenhouse
gas inventory as energy-related carbon dioxide emissions represent 83 percent of total
U.S. greenhouse gas emissions.

EIA emissions estimates at the state level for energy-related carbon dioxide emissions are
based on data contained in the State Energy Data System (SEDS) for the years 1990 to
2004.1 The state-level emissions estimates include energy consumption data for the
following fuel categories: coal, natural gas, and ten petroleum products, including asphalt
and road oil, aviation gasoline, distillate fuel (including some kerosene jet fuel), jet fuel,
kerosene, LPG, lubricants, motor gasoline, residual fuel, and other petroleum products.

The data are presented in three summary tables and in detailed tables for each state. The
summary tables are as follows:

Table 1. 2004 State Energy-related Carbon Dioxide Emissions by Fuel ­ The fuel-
based estimates are developed from primary fuel inputs of coal, natural gas and
petroleum for 2004. State-level energy consumption levels (denominated in British
thermal units or Btu's) are multiplied by national-level carbon emission factors
(denominated in CO2 per Btu) used by EIA in compiling national estimates of energy-
related carbon dioxide emissions. No attempt is made to adjust national carbon dioxide
emission factors by state.

Table 2. 2004 State Energy-related Carbon Dioxide Emissions by Energy Sectors­
Emissions from primary fuel inputs are estimated by end-use sector, as well as the
electric power sector for 2004. At the national level, EIA shares out electric power sector
emissions to the end-use sectors via the amount of electricity sales consumed by that
sector.2 At the state level, electric power sector emissions are not shared out to the other
sectors but are represented independently. This avoids complicated trans-boundary
issues between states that are not encountered when doing a national emission estimate.
In other words, regardless of where the electricity is consumed, the emissions from the
primary energy consumed to generate the electricity are attributed to the state in which
the generation occurred.




1
  See EIA website http://www.eia.doe.gov/emeu/states/_seds.html.
2
  The electric power sector consists of NAICS-22 generators whose primary business is to produce
electricity. Emissions from generators in the industrial and commercial sectors whose primary business is
not the generation of electricity remain in those respective end-use sectors.
Table 3. Summary of State Energy-related Carbon Dioxide Emissions, 1990 - 2004
This table utilizes the fuel-based estimates to produce a time series of total emissions
estimates by state for 1990 to 2004.

Carbon Sequestered by Nonfuel Uses of Energy ­ All three summary tables net out
carbon, and hence carbon dioxide emissions, that is sequestered due to the fact that a
small portion of energy consumption is not combusted because it is used for nonfuel
purposes. At the national level, carbon sequestered in nonfuel products is subtracted
through a relatively complex process from total national-level emissions. Because of
state-level data constraints, a more simplified process is used to allocate the national-
level nonfuel sequestration values to the individual states. Three separate methods are
used, depending on the nonfuel source.

     1. For petroleum products, such as asphalt and road oil and lubricants, where all
        uses are nonfuel and the sequestration rates are straightforward, the amount of
        nonfuel sequestered was directly calculated based on state-level activity data and
        the related national-level carbon coefficients for the particular product.
     2. For liquefied petroleum gases (LPG), industry data were used to apportion the
        total national-level nonfuel sequestration amounts for LPGs to the individual
        states.3
     3. For petroleum products other than the above (petroleum coke, residual fuel, and
        distillate fuel), natural gas, and coal, value added at the NAICS 3251 Basic
        Chemicals level was used to apportion the total national-level nonfuel
        sequestration to the individual States.4

Municipal Solid Waste and Geothermal Power Generation - A line item for
Municipal Solid Waste (MSW) and geothermal power generation is not apportioned to
any state because it is not part of the SEDS database. This value fluctuates between 6.2
to 13.0 million metric tons during the 1990 to 2004 time frame. As such, this source
ranges from 0.1 to 0.2 percent of total U.S. carbon dioxide emissions.

Balancing Item - The balancing item accounts for minor differences between the
national-level inventory and state-level emissions calculations totals. Some of the
difference is caused by adjustments that were made at the national level, but were more
difficult to make at the state level. The balancing item is not attributed to any one state.
The balancing item ranges from -14.1 million metric tons to +7.8 million metric tons. In
percentage terms, the balancing item ranges form -0.3 to 0.1 percent of total U.S. carbon
dioxide emissions.


3
  American Petroleum Institute, Sales of Natural Gas Liquids and Liquefied Refinery Gases. (various
years). Data were aggregated and averaged in order to avoid disclosure of proprietary material.
4
  U.S. Department of Commerce, Economics and Statistics Administration, U.S. Census Bureau, Annual
survey of Manufactures, Geographic Area Statistics: 2000, (Various years).
http://www.census.gov/prod/2002pubs/m00as-3.pdf
Detailed State Tables ­ Beginning for the first time with the 2004 data, detailed state
files have been constructed that show all adjustments for nonfuel use of fossil fuels.
These files also present a time series for emissions by fuels and sectors going back to
1980. These files are available at:
http://www.eia.doe.gov/oiaf/1605/state/state_emissions.html.