S-EPA
430-F-22-003
United States
Environmental Protection
Agency
Data Highlights
Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2020
r >
u
About the Greenhouse Gas Inventory
EPA's annual report, the Inventory of U.S. Greenhouse Gas Emissions and Sinks (the Inventory), provides a
comprehensive accounting of U.S. greenhouse gas emissions and sinks by source, economic sector, and greenhouse
gas going back to 1990. This technical overview summarizes the latest information on U.S. anthropogenic greenhouse
gas emission trends from 1990 through 2020 and includes a preliminary outlook on 2021 emissions. The estimates
presented are calculated using methodologies consistent with those recommended in the 2006 Intergovernmental Panel
on Climate Change (IPCC) Guidelines for National Greenhouse Gas Inventories (IPCC 2006) and where appropriate, its
supplements and refinements. For this latest release, EPA has made several important improvements. For example, EPA
has added estimates for two important sources of methane; emissions from post-meter uses of natural gas, which
includes leak emissions from residential and commercial appliances, industrial facilities and power plants, and natural gas
fueled vehicles; and emissions from flooded lands such as hydroelectric and agricultural reservoirs. Additionally, EPA
worked with researchers to include estimates of methane emissions from large anomalous leak events, such as well
blow-outs.
In preparing the annual Inventory, EPA collaborates with hundreds of experts representing more than a dozen U.S.
government agencies, academic institutions, industry associations, consultants, and environmental organizations. EPA
also collects greenhouse gas emission data from individual facilities and suppliers of certain fossil fuels and industrial
gases through its Greenhouse Gas Reporting Program (GHGRP). The GHGRP does not provide full coverage of total
annual U.S. greenhouse emissions and sinks (e.g., the GHGRP excludes emissions from the agricultural, land use, and
forestry sectors), but it is an important input to the calculations of national-level emissions in the Inventory.
Highlights of Recent Trends in Emissions and Sinks
GHG emissions show decline since 2005
In 2020, total gross U.S. greenhouse gas emissions were 5,981 million metric tons of carbon dioxide equivalent (MMT
CO2 Eq.). Net emissions (including sinks) were 5,222 MMT CO2 Eq, From 2005 to 2020, net emissions declined 21
percent, reflecting the combined impacts of long-term trends in many factors including population and economic growth,
energy markets, technological changes including energy efficiency, and energy fuel choices. The decline in recent years
is due to an increasing shift to use of less C02-intensive natural gas for generating electricity and a rapid increase in the
use of renewable energy in the electric power sector. In 2020, net greenhouse gas emissions decreased by 11 percent
largely due to the impacts of the coronavirus (COVID-19) pandemic on travel and economic activity. Net emissions in
2020 were 7 percent lower than in 1990.
Total U.S. Greenhouse Gas Emissions by Gas
8,000
7,000
6,000
ri-
5,000
al
O
4,000
0
1-
S
3,000
5
2,000
1,000
0
-1,000 _
HFCs, PFCs, SF6 and NF3
Nitrous Oxide
Methane
Carbon Dioxide
Net C02 Flux from LULUCF
Net Emissions
(including LULUCF sinks)
OT-CMC0-a>a>CT>a>a>CT)CT>ooooooooooo£>o^.^
T— T— r-T— T-T— r-CNlCNCSJCMCMCMCMCMCNCNCM^CMCvJCNJCMCMCMCMCNICM
Data Highlights: Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2020
Page 1
-------
More about Carbon Dioxide
CO2 is the primary greenhouse gas contributing to total U.S. emissions, accounting for 79 percent of the total in 2020. Total
CO2 emissions decreased 10 percent between 2019 and 2020. In 2020, fossil fuel combustion (e.g., for electric power
generation) accounted for over 94 percent of CO2 emissions. Changes in CO2 emissions from fossil fuel combustion are
influenced by many of the same long-term and short-term factors already noted above. Fossil fuel combustion CO2 emissions
also depend on the type of fuel consumed (e.g., natural gas) and its carbon intensity.
Other sources of U.S. CO2 emissions include non-combustion emissions from industrial processes (e.g., cement production)
and changes in land use, and are shown in the figure below. Land use, land-use change, and forestry (LULUCF) activities
include fluxes of carbon resulting from land use conversions (e.g., emissions from conversion of forest land to agricultural or
urban use) or land use management practices that remove CO2 from the atmosphere and store it in long-term carbon sinks
(e.g., through net forest growth). The LULUCF sector offset about 14 percent of total gross U.S. emissions in 2020 and is a
steady sink across the 1990 to 2020 time series. Major U.S. sinks include long-term forests and recent conversions of other
land uses to forests.
2020 Sources of Carbon Dioxide (CO2) Emissions
¦812.01
40 -20
Fossil Fuel Combustion
Non-Energy Use of Fuels
Iron and Steel Production
Cement Production
Natural Gas Systems
Other Industrial Processes
Petroleum Systems
Petrochemical Production
Incineration of Waste
Ammonia Production
Lime Production
Other Energy
Net Carbon Stock Change from LULUCF
More about Methane
CH4 accounted for 11 percent of emissions
and has decreased by nearly 7 percent since
2005 and 17 percent since 1990. Emissions
increased by nearly 3 percent from 2019 to
2020. Key trends include reduced emissions
from natural gas systems due to decreases
in emissions from distribution, transmission,
and storage; decreases in emissions from
landfills due to increased landfill gas
collection and less decomposable materials
discarded in landfills; and increased
emissions from livestock in line with
increasing cattle populations.
More about Nitrous Oxide
N2O accounted for 7 percent of emissions
and has decreased by 5 percent since
1990 Emissions decreased by nearly 7
percent from 2019 to 2020. Key trends in
N2O emissions are influenced by changes
in emissions from agricultural soils due to
interannuai weather patterns, fertilizer use,
and crop production; a small decrease of
N2O emissions from stationary combustion;
and a decrease of N2O emissions from
mobile combustion due to national emission
control standards and technologies for on-
road vehicles.
4,343
CO2 as a Portion
of All Emissions
co2
CH4 79%
N20
HFCs, PFCs, SF6 and NF3
20 40 60 80 100
MMT CO* Eq.
120 140 160 180 200
2020 Sources of Methane (CH4) Emissions
Enteric Fermentation
Natural Gas Systems
Landfills
Manure Management
Coal Mining
Petroleum Systems
LULUCF Emissions
Wastewater Treatment
Rice Cultivation
Other Energy
Stationary Combustion
Composting
Field Burning of Agricultural Residues
Other Industrial Processes
Anaerobic Digestion at Biogas Facilities
1175
ChU as a Portion
of All Emissions
co2
CH,
N20
HFCs, PFCs, SF6 and NF3
0 20 40 60 80 100 120 140 160 180
MMT CO* Eq.
2020 Sources of Nitrous Oxide (N2O) Emissions
Agricultural Soil Management
Wastewater Treatment
Stationary Combustion
Manure Management
Mobile Combustion
LULUCF Emissions
Nitric Acid Production
AdipicAcid Production
Other Industrial Processes
Composting
Other Energy
Field Burning of Agricultural Residues
Petroleum Systems
316
N2O as a Portion
of All Emissions
7%
co2
ch4
n2o
HFCs, PFCs, SF6 and NF3
0 5 10 15 20 25 30 35 40
MMT C02 Eq.
Data Highlights: Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2020
Page 2
-------
More about Fluorinated Gases
Emissions of fluorinated gases accounted
for nearly 3 percent of emissions and have
increased by 29 percent since 2005 and 90
percent since 1990. Emissions increased
by 1 percent since 2019. Key trends
include a significant increase in HFCs and
PFCs resulting from the substitution of
ozone depleting substances (ODS) as a
result of efforts to phase out CFCs and
other ODS in the U.S. and increases in
emissions from the electronics industry
reflecting the competing influences of
industrial growth and the adoption of
emission reduction technologies.
2020 Sources of Fluorinated (HFCs, PFCs, SF6, and NF3) Emissions
Substitution of Ozone Depleting
Substances
Electronics Industry
Electrical Transmission and Distribution
HCFC-22 Production
Aluminum Production
Magnesium Production and Processing
HFCs, PFCs, SFe,
and NFa as a Portion
of All Emissions
co2
ch4
n2o
HFCs, PFCs, SF6 and NF3
10
MMT CO2 Eq.
15
20
Emissions by Economic Sector
Greenhouse gases are emitted across five economic sectors: transportation, electric power (electricity generation),
residential/commercial (homes and businesses), industry, and agriculture. For more information on trends in the land use,
land use change and forestry sector, see textbox above titled More about Carbon Dioxide.
U.S. Greenhouse Gas Emissions Allocated to Economic Sectors*
'Land use sinks and U.S. Territories are excluded from this figure.
Transportation Sector
Transportation activities are the largest source of emissions, accounting for 27 percent of total U.S. greenhouse gas
emissions in 2020. From 1990 to 2020, transportation CO2 emissions from fossil fuel combustion rose by 7 percent due in
large part to increased demand for travel. The number of vehicle miles traveled (VMT) by light-duty vehicles (i.e.,
passenger cars and light-duty trucks) increased by 30 percent from 1990 to 2020; VMT by medium- and heavy-duty
trucks increased 107 percent over the same period. While an increased demand for travel has led to increasing CO2
emissions since 1990, improvements in average new vehicle fuel economy since 2005 has slowed the rate of increase of
CO2 emissions. In 2020, light-duty vehicles represented 57 percent of CO2 emissions from transportation fossil fuel
combustion and medium- and heavy-duty trucks and buses represented 26 percent. Petroleum-based products supplied
94 percent of the energy used for transportation, with 57 percent from gasoline consumption in automobiles and other
highway vehicles. Diesel fuel for freight trucks and jet fuel for aircraft accounted for 27 and 10 percent of fuel
consumption, respectively. The remaining 1 percent of petroleum-based energy used for transportation was supplied by
natural gas, residual fuel, aviation gasoline, and liquefied petroleum gases. Renewable fuels account for the remaining 6
percent of energy used for transportation.
Data Highlights: Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2020
Page 3
-------
Fuels Used in Transportation Sector, Onroad VMT, and Total Sector CO2 Emissions
30,000
Other Fuels
Residual Fuel
Natural Gas
Renewable Energy
Jet Fuel
Distillate Fuel
Motor Gasoline
VMT [Right Axis]
C02 Emissions [Right Axis]
OT-CVJfO^incDKCOO^OT-CMCO^tlOCDNOOC^Or-CNJCO^lOCDNCOOO
CDcr>cT>cr>cr)cr)cr>cr>cr>cr>oooooooooo-<— t— t— t— t-t— t— t— c\j
0)0)01010)0)0)0)0)0)000000000000000000000
f— T— <«— t-C\1C\1CNJCNJC\JCMCNC\JCMOJCMCNJCMCNCNC\ICMC\1C\JOJCM
Electric Power Sector
The electric power sector accounted for 25 percent of total U.S. greenhouse gas emissions in 2020. Emissions from the
electric power sector have decreased by approximately 21 percent since 1990, while the carbon intensity of the electric
power sector, in terms of emissions (CO2 Eq.) per QBtu input, has decreased by 32 percent during that same timeframe.
This decoupling of electric power generation and the resulting CO2 emissions is shown below.
Electric Power Generation and Emissions
| 15,000
0)
i!u 10,000
160
140
120
100
80
60
40
20
0
Nuclear
Renewable
Petroleum
Natural
Coal Generation
CO2 Emissions [Right Axis]
Net Generation [Right Axis]
Oi-(Mcotin(OMO(3)o<-Nn'!rifi(flM»®o*-CMn^in(DMomo
0^a>0>CDCTia>a^O^CDO^OOQOOOCDOOQT— TT-*— T— T--<— T— T— T— T— CM
CT>CT>CT>CT>OTCna>CT>CDOOOOCDOOOOCDCDoOOOOOCDOO
¦t-T-T-t-t-t-T-T-T-T-CSJCMCMCMMCMCM(NCM(MCMCNCNICMCVJCMCMCMCMCNCM
Trends in CO2 emissions from fossil fuel combustion have been strongly influenced by the electric power sector, which
until recently has accounted for the largest share of these emissions. The types of fuel consumed to produce electricity
have changed in recent years. Total electric power generation decreased by 3 percent from 2019 to 2020. However, CO2
emissions decreased 10.3 percent from 2019 to 2020 due to increasing electric power generation from natural gas and
renewables and decreasing generation from coal. Carbon dioxide emissions from coal consumption for electric power
generation decreased by 60.2 percent since 2005. The decrease in coal-powered electricity generation and increase in
natural gas and renewable electricity generation have contributed to a 40 percent decrease in overall CO2 emissions from
electric power generation from 2005 to 2020.
Commercial and Residential Sectors
The commercial and residential sectors accounted for 7 and 6 percent total U.S. greenhouse gas emissions in 2020,
respectively. Emissions from the commercial and residential sectors have increased since 1990 and short-term trends are
often correlated with seasonal fluctuations in energy use caused by weather conditions. Carbon dioxide emissions from
natural gas consumption in the residential and commercial sectors decreased 7 percent and 11 percent from 2019 to
2020, respectively. This trend can be attributed to a decrease in heating degree days (9 percent), which led to a
decreased demand for heating fuel in these sectors.
Data Highlights: Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2020
Page 4
-------
Fuels Used in Residential and Commercial Sectors, Heating and Cooling Degree Days, and Total Sector
CO2 Emissions
18,000
16,000
3 14,000
h 12,000
® 10,000
^ 8,000
j? 6,000
£ 4,000
2,000
0
Industry
The industrial sector accounted for 24 percent of U.S. greenhouse gas emissions in 2020. Since 1990, industrial sector
emissions have declined by 14 percent. Structural changes within the U.S. economy that led to shifts in industrial output
away from energy-intensive manufacturing products to less energy-intensive products (e.g., from steel to computer
equipment) have had a significant effect on industrial emissions. EPA's GHGRP data provide insights into underlying
trends in the industrial sector. Between 2019 and 2020, industrial sector coal consumption and natural gas consumption
decreased slightly across all industries.
Agriculture
Agriculture accounted for about 11 percent of U.S. greenhouse gas emissions in 2020 and includes sources such as
enteric fermentation in domestic livestock, livestock manure management, N2O from agricultural soil management, and
combustion from agricultural equipment. In 2020, agricultural soil management was the largest source of N2O emissions,
and enteric fermentation was the largest source of CbU emissions in the United States. Changes in agricultural soil
carbon stocks are included in the land use sector,
O r- CvJ CO ^ in CD I— COmOr-CNJCO^LnCDNCOCTJOT-CNJCO^inCDr^-COCDO
a)CTia)cj)cna)a)CT)CT)CT)oooooooooof-TrT-T-T-T-T-T-T-T-(N
cricncDo^cncricDcncDcnooooooooooooooooooooo
t— t— ¦*— t— ¦*— ¦*— CNJCNJCNJCNJCNJCNJCMCNJCMCNJCNICNJCNJCNJCMCNJCNJCNJCNJCNJCSI
160
140
¦
Coal
120
o
¦
Renewable Energy Sources
100
CD
O)
T"
¦
Petroleum
80
(/>
>
¦
Natural Gas
60
X
CD
¦a
¦
Electricity Use
40
c
¦
C02 Emissions [Right Axis]
20
n
¦
Heating and Cooling
u
Degree Days [Right Axis]
Preliminary Outlook for 2021
Carbon dioxide emissions from fossil
fuel combustion represent about 73
percent of total U.S. C02 emissions.
While the current Inventory does not
include 2021 estimates, preliminary
energy data are available and can be
used to project energy-related C02
emissions. Preliminary 2021 data are
not available for other sectors to
provide projections. The preliminary
energy estimates indicate that in 2021
economic activity recovered from the
2020 COVID-19 pandemic impacts
and contributed to a total energy use
increase of nearly 5 percent and
emissions from energy use increased
by 6 percent (EIA 2021).
Transportation sector emissions
increased 11 percent in 2021
compared to 2020. Overall U.S.
electricity use increased by 3 percent
and emissions from the electric power
decreased use of natural gas. in 2021,
power sector (EPA 2022). The growth
2021 (EPA 2022). Emissions from the
percent respectively.
Comparison of Fossil Fuel CO2 Combustion Emission Projections
er
UJ
CM
O
o
Coal
Jet Fuel
Total Petroleum
Electricity
Diesel Fuel
Gasoline
1 Other
Natural Gas
3,000
2,500
2,000
1,500
I 1,000
500
0
2020 2021 2020 2021 2020 2021 2020 2021 2020 2021
Electric Power Residential & Industrial Transportation Total
Commercial
sector increased 7 percent in part due to a reversion back to increased coal use and
coal use increased 16 percent, and natural gas use declined 3 percent in the electric
in renewable sources continued with renewable energy use increasing 6 percent in
residential and commercial and the industrial sectors increased 5 percent and 3
Data Highlights: Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2020
Page 5
-------
References
!PCC (2006) 2006 IPCC Guidelines for National Greenhouse Gas Inventories. The National Greenhouse Gas Inventories
Programme, The Intergovernmental Panel on Climate Change, H.S. Eggleston, L. Buendia, K. Miwa, T Ngara, and K.
Tanabe (eds.). Hayama, Kanagawa, Japan. Available online at: https://www.ipce-naaip.iaes.or ip/pubiic/2006al/
U.S. Energy Information Administration (EIA) (2022) March 2022 Monthly Energy Review. Available online at:
https://www.eia.qov/totaienerqv/data/monthlv/orevious.ohD
EPA (2022) Clean Air Markets: Power Plant Emission Trends. Available online at: https://www.epa.gov/airrriarkets/power-
plant-emission-trends
For More Information
Additional resources and tools with more information and data related to the U.S. Greenhouse Gas Inventory are
available at: https://www.epa.aov/ahaernissions/inventorv-us-areenhouse-gas-emissions-and-sinks.
Fast Facts on the National-Level U.S. Greenhouse Gas Inventory and U.S. Transportation sector provide a quick
look at trends and an overview of findings
The Greenhouse Gas Inventory Data Explorer
allows users to visualize the data underlying U.S.
Inventory estimates
The full Inventory of U.S. Greenhouse Gas
Emissions and Sinks: 1990-2020 report here
provides access to in-depth information on data
sources and methodologies
Download CSVs of the Inventory report
tables for your own use
L.0855 250.0359
2.9535 140.1771
51184 77.0158
67118 37.51332
42056 62.23148
36348 11.49317
11.768 6168.634
252.4214
132.564
75.96447
59.62693
11.77797
6090.369
2002 2003 2004
5558.284 5618.752 5707.128
248.5888 247.4442 246.9853
136.3256 129.9274 148.1317
71.14309 71.12843 72.18437
37.81659 39.33303 40.83791
57.38888 55.09626 51.98884
12.21272 12.48586 12.76276
6121.759 6174.167 6280.019
2005
5744.754
249.2779
139.6252
70.718
42.15889
48.55994
12.85586
6307.95
2006
5657.845
252.8397
140.8802
72.0775
41.37204
45.92849
12.91301
6223.856
2007 2008 2009 2010
5749.441 5561.517 5190.966 5358.456
250.8707 256.0271 243.6571 245.0927
123.413 125.895 106.6667 114.1591
71.11848 81.97 86.2182 88.91402
42.19085 41.99929 39.55242 42.65702
41.03515 37.49963 35.16869 33.7209 125.4154
.10261 12.24498 11.65686 11.3787 87.27796
6291.171 6117.153 5713.886 5894.378 34.87819
63.22446
11.26947
5339.756 5300.775 5399.791 5496.242 5585.243
128.2632
86.20413
35.10733
64.69306
1L70311
5631.396
1996
5230.333
263.3774
123.7634
86.04635
36.14493
65.76591
12.30346
5817.735
1997 1998
5293.913 5330.448
262.5672 253.8948
132.346 149.6851
84.42657 83.9582
35.77727 35.45946
66.51952 66.60807
12.2622 11.2018
5887.812 5931.256
Data Highlights: Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2020
Page 6
------- |