February 2023

Corrigenda and Data Caveats in using the Inventory of U.S. Greenhouse Gas Emissions and Sinks by
State: 1990-2020

State-level GHG Data Corrigenda

1.	Consistent with international reporting conventions, EPA presents both gross and net GHG total estimates in
the data tables below the charts in the GHG Data Explorer for the national and state-level GHG data. Per
convention and consistent with the national GHG Inventory, state-level gross total estimates should exclude
the LULUCF sector and include only estimates from the Energy, IPPU, Agriculture, and Waste sectors. State-
level net total GHG estimates include the net emissions and removals from all sectors, including the LULUCF
sector. In the recently published state data, for states where the LULUCF sector resulted in net emissions in
any given year, the net and gross GHG estimate totals were the same in the GHG Data Explorer but should
have differed by the net contribution from LULUCF sector (gross estimates were not excluding the LULUCF
sector). This error impacted the presentation of annual state-level gross GHG total estimates for AK, AZ, CO,
HI, ID, MT, NM, NV, SD, UT, and WV in years where the LULUCF sector resulted in net emissions. This error has
now been corrected so gross total GHG estimates for these states (when gross total GHG estimates are
presented) no longer include emissions and removals from the LULUCF sector. This correction has also been
reflected in the standalone excel tables posted on these pages [as of November 1, 2022]
https://www.epa.gov/ghgemissions/state-ghg-emissions-and-removals and

https://www.epa.gov/ghgemissions/methodologv-report-inventorv-us-greenhouse-gas-emissions-and-sinks-
state-1990-2020.

2.	The state estimates in GHG Data Explorer included N20 emissions from nitrogen additions to forest soils.

These estimates should have been excluded from the estimates as they were preliminary data, and not final
data. These preliminary data have been excluded from the state-level estimates in the GHG Data Explorer and
we hope to include this data the next version of the data, noting the next version of the data covering 1990-
2021. This correction only applies to the following states: AL, AK, FL, GA, LA, MS, NC, OR, SC, TN, TX, VA, WA.
This correction has also been reflected in the standalone excel tables posted on these pages [as of November
1, 2022] https://www.epa.gov/ghgemissions/state-ghg-emissions-and-removals and

https://www.epa.gov/ghgemissions/methodologv-report-inventorv-us-greenhouse-gas-emissions-and-sinks-
state-1990-2020.

3.	The state estimates in GHG Data explorer and the standalone excel tables excluded methane estimates from
rice cultivation which occurs in AR, CA, FL, IL, KY, LA, MN, MS, MO, NY, SC, TN, and TX. The data explorer and
standalone excel tables have been corrected to include methane from rice cultivation estimates for these
states [as of February 2, 2023], This correction has also been reflected in the standalone excel tables posted
on these pages https://www.epa.gov/ghgemissions/state-ghg-emissions-and-removals and
https://www.epa.gov/ghgemissions/methodologv-report-inventorv-us-greenhouse-gas-emissions-and-sinks-
state-1990-2020.

4.	The state estimates in GHG Data explorer and the standalone excel tables included some aggregation errors
for some fluorinated gases, i.e., double counting of one PFC (CF4) missing a very small volume gas (HFC). The
aggregation rules have been corrected. The standalone excel table by IPCC sector included an error in the
formula for aggregating waste sector emissions and this has been corrected. This correction has also been
reflected in the standalone excel tables posted on these pages [as of February 2, 2023],
https://www.epa.gov/ghgemissions/state-ghg-emissions-and-removals and

https://www.epa.gov/ghgemissions/methodologv-report-inventorv-us-greenhouse-gas-emissions-and-sinks-
state-1990-2020.

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February 2023

State-level GHG Data Caveats

The state-level estimates were developed to be consistent with the national Inventory, meaning they were
compiled to avoid double counting or gaps in emissions coverage between States. This was done to ensure that
State totals, when summed, would equal totals in the national Inventory.

However, there were some instances where either lack of data or updates in data sources used resulted in state-
level totals that did not add up to the national totals for the categories listed. This was true for the following
source and/or sink categories:

Sector/Emission and/or Sink
Category

Years where
Different

% Difference State totals vs.
national Total

Reason

Energy- FFC C02

2020

0.002% (% differences within
a sector are higher)

The state-level estimates are based
on updated energy use data that will
be incorporated into the next
version of the National Inventory.

Energy-NEU C02

All

Max 0.001%

Rounding, adjustments made to
match up state-level and national-
level NEU values.

IPPU - Electrical Transmission
and Distribution

All years

For 2019, the difference was
1.5%. For all other years, the
difference was 0.2% or less.

There are two errors affecting the
national totals. For 2019, there was
an error in the estimation
methodology for non-reporters. For
all years, there was a unit
conversion error. These errors were
corrected in the state-level
estimates.

LULUCF -

•	Forest land (harvested wood
pools)

•	Forest land (N20 from Forest
Soils)

•	Coastal Wetlands (N20 from
aquaculture)

All years

~3% reduction in the net
LULUCF sector total in 2020
but will vary across time
series.

Note: While a percentage is
provided, it is a percentage
of net emissions and sinks in
the LULUCF sector, so may
not accurately reflect relative
sectoral contribution in a
year, including 2020.

State-level estimates do not include
emission and removals from carbon
stock changes associated with
harvested wood products (HWP),
emissions from N additions (N20) to
Forest Soils, and they also do not
include N20 emissions from
aquaculture as disaggregation of
these sources to the state level will
require further assessment of
potential methods and/or
appropriate surrogate data to
allocate national estimates to
states.

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