TEXAS GREENHOUSE GAS EMISSIONS AND SINKS INVENTORY:

SUMMARY

Texas Greenhouse Gas Emissions for 1990

Million Metric Tons of Carbon Equivalent

^ ^

Total
Energy

Waste Agriculture Industry Land Use

Sector

~ carbon
equivalent

The report Inventory of Texas Greenhouse Gas Emissions and Sinks: 1990-1999
provides a streamlined inventory of greenhouse gas emissions and sinks for Texas for
each year from 1990 through 1999.

The streamlined approach used to develop Texas' inventory includes (1) emissions from
"key" sources and sinks chosen because they account for a large fraction of total na-
tional emissions and (2) emissions from additional sources, chosen because of their
anticipated importance in the state and/or the feasibility of developing estimates due to
readily available activity data. Key sources included in streamlined greenhouse gas
inventories include: carbon dioxide emissions from fossil fuel combustion; methane from
landfills; carbon fluxes from land-use change and forestry; methane emissions from
enteric fermentation; methane and nitrous oxide emissions from manure management;
and nitrous oxide emissions from agricultural soils. These sources typically represent
nearly 90 percent of states' total greenhouse gas emissions.1 The streamlined green-
house gas inventory for Texas also includes estimates of emissions from coal mining,
cement manufacture, oil and gas systems, adipic acid production, and rice cultivation. All
of these sources are expected to account for more than 90 percent of Texas' green-
house gas emissions.

Emissions for each source were estimated using methods from the 1999 Emission
Inventory Improvement Program, Volume VIII: Estimating Greenhouse Gas Emis-
sions. According to these estimates, Texas' greenhouse gas emissions increased from
178 million metric tons of carbon equivalent (MMTCE) in 1990 to 189 MMTCE in 1999.

1 Because these key sources do not account for total state emissions, the Texas Inventory should
not be directly compared to other state inventories.


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Texas Greenhouse Gas Emissions for 1990

BY SECTOR

co2

(MMTCE)

Methane
(MMTCE)

Nitrous Oxide
(MMTCE)

HFCs, PFCs,
and SF6
(MMTCE)

Total GHG
Emissions
(MMTCE)

Energy - Residential

3.5

*

*

*

3.5

Energy - Commercial

3.3

*

*

*

3.3

Energy - Industrial

52.3

*

*

*

52.3

Energy - Transport

42.1

*

*

*

42.1

Energy - Utility

48.3

*

*

*

48.3

Energy - Exported Electricity

*

*

*

*

0.0

Energy - Other

*

3.9

*

*

3.9

Total Energy

149.6

3.9

*

*

153.5

Waste

*

5.3

*

*

5.3

Agriculture

*

5.5

3.9

*

9.4

Industry

0.9

*

4.1

*

5.0

Land Use

4.8

*

*

*

4.8

Total

155.3

14.7

8.0

*

178.0

All emissions are reported in million metric tons of carbon equivalent (MMTCE).

An asterisk ( * ) indicates that emissions of the gas from this sector were zero, insignificant, or not reported.

Emissions due to coal mining and extraction of natural gas and oil are included in the energy - other figures,
and emissions from biofuel combustion are excluded.

The principal greenhouse gas was carbon dioxide, comprising 570 million metric tons
(155.3 MMTCE) in 1990. Other emissions in 1990 included methane with 2.57 million
metric tons (14.7 MMTCE), and 0.09 million metric tons of nitrous oxide (8.0 MMTCE).

The majority of carbon dioxide emissions were from fossil fuel combustion (96%), with
the remainder due to land-use change and forestry (3%) and cement manufacture (1%).
Sources of methane emissions were landfills (36%), domesticated animals (31%), oil
and gas systems (26%), manure management (5%), rice cultivation (2%), and coal
mining (<1%). Nitrous oxide emissions were attributable to adipic acid production (51%),
agricultural soil management (45%), and manure management (4%).

Texas emissions in 1990 were 10.4 MTCE per capita, compared to 1990 U.S. emissions
of 5.2 MTCE per capita for the same emission sources.


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