United States
Environmental
Protection Agency
Office of Atmospheric
Programs (6207A)
Washington, DC 20005
EPA-430-R-19-010
October 2019
Global
Non-C02
Greenhouse
Gas Emission
Projections &
Mitigation
2015-2050

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How to Obtain Copies
You can electronically download this document on the U.S. EPA's homepage at https://www.epa.gov/global-
mitigation-non-co2-greenhouse-gases.
All projections and mitigation data described in this document for the full time series 1990 through 2050,
inclusive, are made available at the internet site mentioned above. In addition, the data are accessible through a
data exploration tool at https://cfpub.epa.gov/ghgdata/nonco2/.
For Further Information
Contact Mr. Shaun Ragnauth, Environmental Protection Agency, (202) 343-9142, ragnauth.shaun@epa.gov, or
Mr. Jameel Alsalam, Environmental Protection Agency, (202) 343-9807, alsalam.jameel@epa.gov.
Acknowledgements
This report was prepared by Abt Associates, Inc., ICF International, and RTI International under contracts with the
U.S. Environmental Protection Agency (EPA).
Abt Associates and ICF International conducted the emission projections analysis and authored the projections
portions of the report. RTI International conducted the mitigation analysis for all sectors and authored the
mitigation portions of the report.
Abt Associates, Inc.
Dan Bosoli
ICF International
Mollie Averyt
Cara Blumenthal
Rani Murali
Sabrina Andrews
Rebecca Ferenchiak
Deborah Harris
Kristen Jaglo
Megha Kedia
Robert Lanza
Lance LaTulipe
Jerry Marks
Andrew Stilson
Neha Vaingankar
Mollie Carroll
Katrin Moffroid
RTI International
Jeffrey Petrusa
Kyle Clark-Sutton
Justin Larson
Alison Bean
Robert Beach
We thank the following external reviewers for their time and feedback:
E. Lee Bray (U.S. Geological Survey)
Phillip Cunningham (Ruby Canyon Engineering)
James W. Levis (North Carolina State University)
Miriam Lev-on (The LEVON Group, LLC)
April B. Leytem (U.S. Department of Agriculture)
Neville Millar (Michigan State University)
Raymond C. Pilcher (Raven Ridge Resources)
Pallov Purohlt (IIASA)
Keith A. Smith (University of Edinburgh)
Global Non-C02 Greenhouse Gas Emission Projections & Mitigation: 2015-2050

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Table of Contents
• »*	m*

Introduction	2
Energy	11
Coal Mining	12
Natural Gas and Oil Systems	16
Combustion of Fossil Fuels and Biomass	22
Industrial Processes	25
Nitric and Adipic Acid Production	26
Electronics	30
Electric Power Systems	34
Metals	38
Substitutes for Ozone-Depleting Substances 44
HCFC-22 Production	48
Agriculture	53
Livestock	54
Croplands	58
Rice Cultivation	62
Waste	67
Landfills	68
Wastewater	72
References	76
Global Non-C02 Greenhouse Gas Emission Projections & Mitigation: 2015-2050

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Introduction
*
4br
This report is the latest installment of the U.S.
Environmental Protection Agency's (EPA's) non-carbon
dioxide (non-C02) greenhouse gas (GHG) assessments
and combines two long-running EPA report series:
Non-C02 Greenhouse Gases: International Emissions
and Projections1.2 and Global Mitigation ofNon-C02
Greenhouse GasesM Combining the"projections"and
"mitigation" reports provides an opportunity to better
align these two documents and their respective uses.
This report provides a consistent and comprehensive set
of (1) historical and projected estimates of emissions and
(2) technical and economic mitigation estimates of non-
C02 GHGs from anthropogenic sources for 195 countries.
The analysis provides information that can be used to
understand national contributions of GHG emissions,
historical progress on reductions, and mitigation
opportunities.
The projections were generated using a combination
of country-reported inventory data supplemented with
EPA-estimated calculations consistent with inventory
guidelines of the Intergovernmental Panel on Climate
Change (IPCC).The mitigation estimates were generated
using a bottom-up, engineering cost approach that
analyzed the costs of a wide range of mitigation
technologies and incorporated them into an economic
tool called a marginal abatement cost (MAC) curve, which
summarizes the cost and emission reductions achievable
from each source.
Historical emission estimates were incorporated from
country-reported data from 1990 through 2015, and
emissions were projected through 2050; mitigation
estimates are available for 2020 through 2050. The
projections results are a "business-as-usual" (BAU)
scenario with emission rates consistent with historical
levels and do not include future effects of policy changes.
Mitigation options represented in the MAC curves reduce
emissions from the BAU scenario. Although emission
and mitigation estimates are available through 2050, this
report focuses on projections and mitigation estimates
in the year 2030 to provide more near-term results for
discussion.
Global Non-C02 Emission by Gas and Sector in 2015
(Non-C02 GHGs = 12,010 MtC02e)
Non-CO;
(25%)
CH4 (67%)
N2Q (25%)
F-GHGs (8%)
Industrial Processes (10%)
Waste (13%)
Energy (29%)
Agriculture (48%)
Global Anthropogenic Non-CO*
Greenhouse Gas Emissions: 1990-2020
The EPA estimates that global non-C02 GHG emissions
in 2015 totaled approximately 12,010 MtC02e. When
added to a global C02 emission estimate for 2015 of
approximately 36,000 MtC02e,s anthropogenic non-C02
emissions represent 25% of the global GHG emissions
emitted annually on a C02 equivalent basis in 2015.
Source Categories and GHGs Included in this Report
Non-C02 GHGs
The GHGs included in this report are the direct non-
C02 GHGs covered by the United Nations Framework
Convention on Climate Change (UNFCCC): methane
(CH4), nitrous oxide (N20), and fluorinated greenhouse
gases (F-GHGs) that include hydrofluorocarbons (HFCs),
perfluorocarbons (PFCs), sulfur hexafluoride (SF6), and
nitrogen trifluoride (NF3). Compounds covered by the
Montreal Protocol are not included.
Sector/Source
ch4
n2o
HFCs
PFCs
sf6
nf3
Energy
Coal mining activities
•





Natural gas and oil systems
•





Combustion of fossil fuels and biomass
•
•




Industrial Processes
Nitric and adipic acid production

•




Electronics manufacturings


•
•
•
•
Electric power systems




•

Metals






Primary aluminum production



•


Magnesium manufacturing




•

Use of substitutes for ozone-depleting substances^


•



HCFC-22 production


•



Agriculture
Livestock






Enteric fermentation
•





Manure management
•





Croplands (agricultural soils)

•




Rice cultivation
•
•




Waste
Landfilling of solid waste
Wastewater
a Electronics manufacturing includes semiconductors, photovoltaics,and flat panel displays.
b Substitutes for ozone-depleting substances include uses in refrigeration and air-conditioning, solvents, foams, aerosols, and fire extinguishers.
Global Non-C02 Greenhouse Gas Emission Projections & Mitigation: 2015-2050

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These non-C02 GHGs are more potent (per unit weight)
than C02 at trapping heat within the atmosphere.
Additionally, some non-C02 GHGs can remain in the
atmosphere for longer periods of time than C02. Global
warming potential (GWP) is the factor that quantifies the
heat-trapping potential of each GHG relative to C02.
Global Warming Potential Factors by Gas
Greenhouse Gas
GWPa Factor
C02
1
ch4
25
n2o
298
HFC-23
14,800
HFC-32
675
HFC-125
3,500
HFC-134a
1,430
HFC-143a
4,470
HFC-152a
124
HFC-227ea
3,220
HFC-236fa
9,810
HFC-4310mee
1,640
cf4
7,390
c2f6
12,200
C4F10
8,860
C6F14
9,300
nf3
17,200
sf6
22,800
a100-year time horizon.
Source: Intergovernmental Panel on Climate Change (IPCC). 2007.
Climate Change 2007: The Physical Science Basis. Contribution
of Working Group I to the Fourth Assessment Report of the
Intergovernmental Panel on Climate Change. S. Solomon, D. Qin,
M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M.Tignor,and H.L.
Miller (eds.). Cambridge, United Kingdom: Cambridge University
Press.e
Methods Overview
General Methods
The methodologies employed to generate non-C02 GHG
emission projections and mitigation estimates build
on those used in previous reports from this series.?,8,9,10
Updates and enhancements have been made to both
the projections and mitigation methodologies for this
report. A summary of the projections and mitigation
methodologies, along with a discussion of enhancements
and changes since the last publications, is presented in
this section.
The full methodology used to develop the emission
and mitigation estimates presented in this report is
documented in the peer-reviewed EPA report Global
Non-C02 Greenhouse Gas Emission Projections & Marginal
Abatement Cost Analysis: Methodology Documentation
(EPA-430-R-19-012).
Emission Projections: Methods
The EPA prepared a complete set of non-C02 GHG
emission estimates, regardless of available country-
reported estimates, in a consistent manner across all
countries to produce a global inventory." To develop
the estimates of historical and BAU projected emissions,
the EPA used publicly available emission estimates from
official nationally prepared GHG reports^ in combination
with EPA-estimated emissions consistent with the 2006
IPCC Guidelines for National Greenhouse Gas Inventories
(IPCC Guidelines).13
To project emissions, the EPA used drivers based on
globally available growth rate or activity data specific to
each source. Depending on available information, the
projected emission estimates for each country and source
are either (1) a composite of historical country-reported
emissions and calculated estimates or (2) calculated
estimates based on IPCC default emission factors and
globally available activity data. In most cases, some
country-reported data are available, so the composite
approach was used. The second approach was only
used when no country-reported data are available for a
source category. For estimates based on the composite
approach, the Tier 1 calculated emission estimates were
used to determine trends through the time series, but the
emission factors (i.e., emissions per unit of activity data)
derive primarily from country-reported information.
The projections results are a BAU, or baseline, scenario
with fixed emission factors. Although the BAU scenario
generally does not explicitly model emission reduction
policies undertaken by individual countries and the
default IPCC factors generally reflect uncontrolled
emissions, the composite emission projections do include
historical emission reductions. To the extent that emission
reductions are reflected in country-reported base-year
data, those rates were used throughout the projection
time series. Thus, the degree to which reductions are
included in an estimate corresponds to the extent to
which reductions are reflected in country-reported data.
Mitigation Estimates: Methods
The mitigation option analysis throughout this report
was conducted using a common methodology and
framework. MAC curves were constructed for each
region and sector by estimating the "break-even" price
at which the present-value benefits and costs for each
mitigation option equilibrate. The methodology produces
a curve where each point reflects the average price and
reduction potential if a mitigation technology were
Illustrative MAC Curve
Business-as-Usual Projections
In this report, the terms "business as
usual,""BAU," and "baseline" all refer to
the non-C02 emission projection results
and are used interchangeably. The BAU
scenario uses projected emission rates
consistent with historical levels and
does not model future effects of policy
changes.
applied across the sector. In conjunction with appropriate
baseline and projected emissions for a given sector, the
results are expressed in terms of absolute reductions of
C02 equivalents (million metric tons of C02 equivalents,
MtC02e). For example, at a price of zero dollars per
metric ton of C02 equivalent (tC02e), The figure below
shows the level of global abatement available in 2030
at the point where the curve crosses the horizontal
x-axis (785 MtC02e). These reductions are available
given current technologies at no cost and represent 6%
of total emissions. Another 22% of BAU emissions can
be mitigated at increasing prices, up to a total of 3,805
MtC02e, the maximum abatement potential. This leaves
73% of total emissions as a residual.
The mitigation analysis accounts for country differences in
industry structure and available infrastructure when data
o
u


-------
are available on a sector-by-sector basis. Additionally, the
analysis accounts for country/regional differences in the
price of mitigation through a series of international cost
indices (labor, nonenergy materials, energy) to create
a more heterogenous representation of emissions and
mitigation costs and benefits across countries.
The MAC curves that describe the mitigation estimates
in this report represent the techno-economic mitigation
potential for each source and technology evaluated.
Derived from a bottom-up engineering cost analysis, the
MAC curves represent emission reductions available at
incrementally higher prices. The total technical potential
refers to the maximum technically achievable emission
reduction from a given source or mitigation option.
The mitigation at a given price represents the emission
reductions that are economic, or the break-even point,
at that price incentive (e.g., $0 per ton of C02 equivalent
[tC02e]).
Methodological Enhancements
For this report, updates to the MAC model introduced
two major methodological enhancements: incorporating
the effects of technology change on mitigation costs and
their reduction efficiencies and developing regionalized
sectoral MAC curves for the United States. This report
has a global focus and reports non-C02 GHG emission
projections and mitigation estimates at the country level.
The incorporation of technology change in existing MAC
curve calculations implies two important updates to the
previous estimates. First, static capital, labor energy, and
materials factors are now allowed to adjust every year,
representing cost savings due to technological change.
Second, by applying a reduction efficiency improvement
factor to the current technical effectiveness for each
mitigation option in the model, a dynamic reduction
efficiency factor was introduced that improves over time.
The figure below depicts the effects of implementing
technological change in the MAC model. The result is
a shift of the vertical asymptote (maximum abatement
potential line in the figure) outward due to the reduction
efficiency improvements, thereby increasing the total
technical mitigation potential. The cost reductions
associated with the learning curve result in a downward
shift of parts of the MAC curve, effectively lowering
abatement costs.
Illustrative MAC Curve Showing the Effects of Technological Change
o
o
u
4—
o
a>
S
w/oTech Change
i w/Tech Change
/
/
Cost Reductions at j
the Same Level ojy
Abatement
Abated GHG Emissions
(MtC02e)
Reduction Efficiency
Improvements
6
Global Results
Global Non-C02 Emissions, by Sector (MtC02e)
Between 1990 and 2015, global non-C02 emission levels
rose by about 29%. Over this same period emissions
of CH4 increased 19%, N20 emissions increased 32%,
and F-GHG emissions increased 231%. Between 2015
and 2030, global non-C02 emissions are estimated to
continue to increase by approximately 17%, growing
from 12,010 to 14,031 MtC02e. Emissions of F-GHGs are
projected to increase 86% from 2015 through 2030, much
faster than CH4 (9%) and N20 (14%).
Global Non-C02 Emissions by Gas (MtC02e)

18,000

16,000
"aT
14,000
C5

U
12,000
2

w
10,000
o

"w
t/i
8,000
I
LLI
6,000

4,000

2,000
16,496
14,031
12,010
9,317
9,842
00-
1990 2000 2015 2030 2050
¦ N20 ¦ F-GHGs ¦ CH4
This projection represents a BAU scenario using emission
rates consistent with historical levels and that does
not model future changes resulting from policies and
measures.
In 2030, the total global non-C02 GHG mitigation
potential is estimated to be approximately 3,805 MtC02e,
or 27% of non-C02 GHG emissions in that year. The total
estimated mitigation potential from CH4 is approximately
2,600 MtC02e, representing 68% of total non-C02 GHG
mitigation potential in 2030. Mitigation potential from
F-GHGs is estimated to be about 829 MtC02e in 2030, or
22% of total non-C02 GHG mitigation potential in 2030.
F-GHG mitigation potential is estimated to more than
double to 2,086 MtC02e in 2050 as baseline emissions
from F-GHG sources are projected to grow over time.

18,000

16,000
"57
14,000
d1

u
4—>
12,000
2


cz
10,000
o

'

8,000
I

LLI
6,000

4,000

2,000
16/196
14,031
12,010
9,317
9,842
0 6

2050
1990 2000 2015 2030
¦	Waste	¦ Energy
¦	Industrial Processes	¦ Agriculture
In 2030, the energy sector accounts for 1,265 MtC02e of
mitigation potential followed closely by the waste sector
at 887 MtC02e.The industrial processes and agriculture
sectors account for 1,060 and 681 MtC02e of mitigation
potential, respectively.The total technical mitigation
potential from the agriculture sector accounts for 10% of
baseline emissions in 2030, while the mitigation potential
from the energy and waste sectors accounts for 35% and
47% of baseline emissions, respectively.
Mitigation Potential and Residual Emissions by
Sector, 2030
Energy
MM
Baseline: 3,585 MtC02e -
Industrial
Baseline: 2,202 MtC02e -
Agriculture
3%y|jggj|
Baseline: 6,339 MtC02e -
Waste
Baseline: 1,905 MtC02e -
¦ Reductions at
No Cost
Technically Feasible
at Increasing Costs
Residual
Emissions
Global Non-C02 Greenhouse Gas Emission Projections & Mitigation: 2015-2050 7

-------
The mitigation potential for CH4 is 30% of baseline
emissions, while the mitigation potentials for N20 and
F-GHGs are 12% and 45%, respectively.
Mitigation Potential and Residual Emissions by Gas,
2030
CH.
Baseline: 8,796 MtCO e
N,0
Baseline: 3,377 MtC02e
F-GHG
111
Baseline: 1,858 MtC02e
¦ Reductions at
No Cost
Technically Feasible
at Increasing Costs
Residual
Emissions
The following figure shows the total BAU emission
projections (dashed line), emissions resulting from
implementing cost-effective mitigation potential at
marginal costs (abbreviated as MC in the figure legend)
less than $0/tCO2e (solid line), and residual emissions
by sector after all technically available mitigation
technologies have been applied. In 2030, the total
mitigation potential is 3,805 MtC02e, a 27% reduction
in total global non-C02 emissions below the baseline
projection. The figure shows that over time non-C02
emissions can be held roughly constant by deploying
available mitigation technologies. These emissions
that remain after mitigation options are implemented
are called "residual" emissions. Achieving long-term
reductions of non-C02 emissions below the 2015 level
would require development of new or more effective
mitigation technologies.
Global Non-CO? Emissions
For this report, emission sources were grouped into
four economic sectors: energy, industrial processes,
agriculture, and waste. Although C02 emissions are
concentrated in the energy sector, agriculture accounts
for the largest share of non-C02 emissions throughout
the time series. Emissions from the industrial processes
and waste sectors are projected to grow at the fastest
rates between 2015 and 2030,76% and 23%, respectively.
Global Non-C02 Emissions by Sector and Source, 2015
Other Industrial (< 1%) •
ODS Substitutes (5.9%)
Nitric and Adipic Acid (1.4%).
EPS (<'
Electronics (<'
Metals (< 1%)-
HCFC-22 (1.3
Wastewater (5%)
Other Waste (< 1%)
Landfills (7.6%)
Combustion of Fossil Fuels and Biomass (6.8%)
Other Energy (< 1%)
Coal Mining (8.1%)
Natural Gas and Oil Systems (14%)
lp>^1,544MtC02e
jlndustria^O^0
J Processes
1.249 MtCO,e
Agriculture
5,766 MtC02e
k	Energy
3,452 MtC02e
29%
Croplands (16%)
Livestock (25%)
Rice (5.2%)
Other Agriculture (1.i
BAU Emission Projections and Residual Emissions by
Sector
25
20
2010
2020
2030
2040
2050
i Agriculture
i Energy
Industrial Processes
i Waste
Baseline Emissions
. MC < $0/tCO2e
MC = marginal cost.
Country-Level Results
In addition to global results, throughout this report each
source category discussion includes information on top
countries'baseline projections and mitigation potential.
Globally, the countries with the top 5 total non-C02 GHG
emissions in 2030 under the BAU scenario are China,
the United States, Russia, India, and Brazil.The maps
are annotated with 2030 emissions in MtC02e. Because
these countries have some of the largest economies
globally, they are among the top emitters in many source
categories as well.
In many cases, the countries with the largest baseline
emissions are also the countries with the largest
mitigation potential. The following panel displays MAC
curves for the top 5 countries with the largest non-C02
GHG BAU emissions in 2030 along with a MAC curve
representing the mitigation potential from the rest of the
world.
Countries with the Largest Emissions, 2030
*s
Rest of World: 7,487 MtC02e
Top 5 Emitters
China
United States
Russia
India
Brazil
Global Non-C02 Greenhouse Gas Emission Projections & Mitigation: 2015-2050

-------
Marginal Abatement Cost Curves, 2030
China	¦
United States
Russia
n
Rest of World
/
1,000
1,500
2,000
1,000
1,500
2,000
1,000
1,500
2,000
Uses and Application of Non-C02 GHG Emission
Projections and A/litigation Estimates Data
The emission projections and mitigation datasets in this
report are intended to provide technical information
that can be useful in economic modeling and climate
mitigation analysis.The results have not been evaluated
with respect to their fitness for particular applications.
These non-C02 datasets are of particular use to economic
and integrated assessment models that evaluate the
effect of GHG emissions and the cost and availability of
mitigation from the non-C02 GHG sectors. A consistent
framework across countries and regions, such as the
one applied to develop these data, is particularly useful
for models that have a global or large regional spatial
coverage.
The results in this report are generally presented at
aggregate source and sector levels with country-
and subsource-level detail. The underlying non-C02
emission and mitigation data are available at the source
and country levels. Because of the global coverage
of this analysis, there is limited ability to capture the
unique circumstances of countries. In some cases,
specific country-level historical emission inventories
were unavailable. In these instances, the EPA used
calculated estimates based on default methodologies
and emission factors. In other cases, countries reported
non-C02 GHG emissions in their inventories for source
categories not included in the projections or mitigation
analyses. For completeness, these are included in sector
charts and underlying datasets as "Other Energy,""Other
Agriculture," etc., but no analysis was done on these
emissions. Subsource disaggregation is based on default
methodologies and may not match country-reported
information. Depending on activity data projections
available for each source category, projected trends may
reflect large regions or in some cases global aggregate
demand trends. For the mitigation estimates, although
the EPA strove to capture regional heterogeneity, data
to model mitigation technology implementation at
the country level are limited. In these cases, data were
extrapolated from known conditions in other proximate
or similar regions.
Details about each source and mitigation option
modeled, as well as specific information about the
estimation of emission projections, are available in the
accompanying methodology document to this report,
Global Non-C02 Greenhouse Gas Emission Projections
& Marginal Abatement Cost Analysis: Methodology
Documentation.
10
ENERGY
J
t I
Introduction
The energy sector is the second largest contributing
sector to global emissions of non-C02 GHGs, accounting
for 29% of global non-C02 emissions in 2015. This section
presents global energy-sector CH4 and N20 historical and
projected emissions and the mitigation potential for the
following source categories:
•	Coal mining (CH4)
•	Natural gas and oil systems (CH4)
•	Combustion of fossil fuels and biomass (CH4, N20)
Projections were estimated for all sources; however,
complete data to estimate MAC curves globally are
available for only coal mining and natural gas and oil
systems. These two sources represented 28% and 48% of
energy-related emissions in 2015, respectively. Energy-
sector emissions increased 29% between 1990 and 2015.
Between 2015 and 2030, global energy-sector emissions
are projected to increase 4% under a BAU scenario,
reaching 3,585 MtC02e in 2030. Natural gas and oii
activities are projected to remain the largest contributor
to non-C02 emissions from the energy sector; stationary
and mobile combustion emissions are projected to grow
15% between 2015 and 2030, thereby surpassing coal
mining emissions as the second largest contributor for
this sector. Emissions from coal mining activities are
projected to decrease by 6% between 2015 and 2030 as
the energy sector transitions from coal to natural gas.
Historical and Projected Emissions from the Energy
Sector
5,000
« 4,000
g 3,000
o
w 2,000
I 1,000
00-^^5—^^^
1990 2000 2015 2030 2050
Other Energy
Combustion of Fossil
Fuels and Biomass
Coal Mining
Natural Gas and
Oil Systems
Mitigation potential from the energy sector is
approximately 1,265 MtC02e in 2030, accounting for
64% of coal emissions and 38% of oil and gas emissions.
Mitigation potential in the energy sector represents 33%
of total global non-C02 mitigation potential in 2030.
Emission Reduction Potential, 2030
Baseline: 3,585 MtC02e	
Reductions at No Cost
Technically Feasible at Increasing Costs
Residual Emissions
Global Non-C02 Greenhouse Gas Emission Projections & Mitigation: 2015-2050 11

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Coal Mining
Source Background
CH4 is produced during the process of Qualification, where
vegetation is converted by geological and biological forces
into coal. Coai seams and the surrounding rock strata store CH4.
Natural erosion, faulting, or mining can reduce pressure above
or surrounding the coal bed and liberate the CH4. Because CH4 is
explosive, the gas must be removed from underground mines high
in CH4 as a safety precaution.
The quantity of gas emitted from mining operations is a function
of two primary factors: coai rank and coai depth. Coal rank is a
measure of the carbon content of the coal, with higher ranks
corresponding to higher carbon and CH4 content. Coals such as
anthracite and semianthracite have the highest coal ranks, while
peat and lignite have the lowest. Pressure increases with depth and
prevents CH4 from migrating to the surface; thus, underground
mining operations typically emit more CH4 than surface mining
operations. Additionally, post-mining processing of coal and
abandoned mines release CH4.
Historical Trends
Between 1990 and 2015, global CH4 emissions from coal mining
are estimated to have increased by 54%. Underlying this trend
have been increases in global coal production with volumes
increasing by 60% over the period. Emissions have increased in
step with production, suggesting low historical mitigation of CH4
from coal mining.
2030 Emissions by Gas and Subsource
Underground mining constitutes almost thesntirety ©fail
emissions at approximately 98%, while surface mining has
little Impact on the results, w
Gas
Subsource
100
CH4(100%)
Surface (2%)
Underground (98%)
Projected Emissions &Top Emitting Countries
Emissions (MtC02e)
From 2015 through 203G; emissions-are
projected to decrease by about 6% ft?
approximately 912 MtECJfl in 2030:
967
G17
1990 2000 2015 2 0 3 0 2050
Emissions (MtCO^e)
2030 Emissions from Top 5 Emitting Countries
Rest of World: 133 MtC02e


Top 5 Emitters
a
China
Russia
United States
India
Australia
12
Key Points
•	Coal mining accounts for 6% of total global
anthropogenic non-C02 GHG emissions in 2030.
•	Expected reductions in reliance on coal in certain
major consuming countries such as China, the United
States, and Russia cause global emissions to decrease
in future years, which offsets expected increases in
other countries such as India.
•	Underground mining is the largest contributor of
emissions from coal mining because of a higher
proportion of total production from this activity and
higher emissions intensity than surface mining.


Projected Trends
From 2015 through 2030, CH4 emissions from coal mining
are projected to decrease by about 6%. This projection
corresponds to expected decreases in reliance from major
coal-consuming countries such as the United States and
China, while global growth remains fairly flat.is
The 10 top emitting countries comprise 94% of global
emissions in 2030. Each of these top emitters ranks within
the top 10 in total coal production in 2015. By 2030, China
is the largest contributor to emissions from coal mining
based on extensive production and use of this resource.
However, China's reliance on coal is expected to decline
because of a slowing economy, reduction commitments,
and policies currently being implemented to address air
pollution.The U.S. Energy Information Administration (EIA)
projects coal consumption in China to decrease by 6%
from 2015 through 2030; however, the country remains
the largest emitter throughout the same projection
period.16 In contrast, India is the fourth highest emitter
in 2030 based on projected increases in the country's
reliance on coal in future years.
Underground Mining
Underground mining represents the majority of coal
produced globally. Projections are driven by regional
or country-specific consumption, which decreases in
a number of major consuming countries.^ Generated
emission volumes are significantly larger from this
activity than surface mining per unit of production.
Given this and the higher proportion of total production
from this activity, this subsource is the main contributor
to coal mining source category emission results.
Surface Mining
European countries tend to have higher proportions of
surface mining compared to underground, although
those countries represent a small portion of global
production. Projections are driven by consumption,
which is expected to remain fairly flat globally but to
decrease in certain countries.is Emissions generated
from this practice are less intensive compared to
underground mining. Given lower production and less
intensity per unit of production, this subsource does not
have as much of an impact on overall results.
Global Non-C02 Greenhouse Gas Emission Projections & Mitigation: 2015-2050 13

-------
Key Points
•	The global CH4 abatement potential in coal
mining is projected to be 582 MtC02e (64%
of baseline emissions) in 2030.
•	An estimated 2% of abatement potential in
the coal source category can be achieved at
prices below $0/tC02e; 95% of abatement
potential is technically feasible at prices
below $20/tC02e.
•	This analysis did not model abatement
measures for surface mining.
Abatement Measures
This analysis considered six abatement
measures for CH4 emissions in underground
coal mining: recovery for pipeline injection,
power generation, process heating,
flaring, and catalytic or thermal oxidation
of ventilation air methane (VAM). These
reduction technologies consist of one or more
of the following primary components: (1) a
drainage and recovery system to remove CH4
from the underground coal seam, (2) the end-
use application for the gas recovered from the
drainage system, and (3) the VAM recovery or
mitigation system.
High-quality CH4 is recoverable from coal
seams by drilling vertical wells from the
surface up to 10 years in advance of a mining
operation or drilling in-mine horizontal
boreholes several months or years before
mining. However, most mine operators
exercise just-in-time management in
developing new operations; subsequently,
horizontal cross-panel boreholes are installed
and drain gas for 6 months or less.
Once recovered, CH4 can be used for energy
purposes. Specifically, recovered CH4 can be
injected into a natural gas pipeline or used
on-site for electricity or heat generation.
Recovered CH4 that is not used for energy
can be flared instead of released into the
atmosphere. Flaring results in a iower GWP
than allowing the CH4 to directly enter the
atmosphere. At mines where the ventilated
mine air has a low concentration of CH4
(0.25% to 1.25%), the recovered gas can be
oxidized and combusted. The by-products of
the combustion process are water and C02.
Total Reduction Potential
Reducing emissions by31 compared with the 2020 baseline is CDst-eftectte
(below $0/tGO:3e}.,An additional reduction ^available using technologies
With increasingly higher costs.Thf ^ost^ftectil'fer'eductiori potential remains at
2% in 2030 but rises to5% in 2050.
Marginal Abatement Cost Curves, 2030
36%
Baseline: 958 iVltCO e.
36%
Baseline: 912 MtCQ,e -
2020
2030
2050
Baseline: 817 MtC02e -
Reductions at
No Cost
Technically Feasible
at Increasing Costs
Residual
Emissions
Reduction Potential by Technology
In 2030, VAM oxidation is the; leading emission abatement measure, but using
degasification for power generation presents the largest abatement potential
at prices beloVv $G/|C©j5,The two technologies combined contributefffilsof
potential abatement in 2030.
VAM Oxidation
Degasification for Power Generation
Degasification for Pipeline Injection
I
Open Flare
On-site Use in Mine Boiler
On-site Use in Coal Drying
100 200 300 400 500
MtC02e
Reductions achievable at costs less than $0/tC02e
Reductions achievable at costs greater than $0/tC0 e
Taken together, the top 5 countries in terms of emissions represent 86% of all potential global abatement from coal mining in
2030. China is responsible for 69% of global abatement potential in coal mining (403 MtC02e).
China
Russia
$100
$80
$60
$40
$20
$0
-$20
$100
$80
$60
$40
$20
$0
-$20
100 200
India
$100 r
$80
$60
$40
$20
$0
-$20
$100
J-
Australia
100 200
$40
$20
$0
-$20
United States
$100 r
$80
$60
$40
$20
$0
-$20
500 0
r
©
Rest of World
$100
$80
$60
$40
$20
$0
-$20
-$40
r
100 200
Abatement Potential
In 2030, the adoption of the suite of abatement
measures considered in this analysis can reduce total
annual emissions from coal mining by approximately
64%. The MAC curve analysis results show that 78% of
potential CH4 abatement is achievable at prices below
$10/tCO2e. At or below a break-even price of $20 or
less, 95% of abatement potential is technically feasible.
In 2030, the top 3 mitigation technologies globally
are the use of stand-alone VAM, degasification for
power generation, and degasification for pipeline
injection. Using stand-alone VAM can abate up to
443 MtC02e (76% of coal mining's total abatement
potential), although it is one of the most expensive
abatement options in coal mining because of three
key factors: (1) the equipment itself is large and costly;
(2) there is no revenue source; and (3) only a handful of
technologies have been demonstrated at a commercial
scale and, as such, economies of scale in production
have not been realized. Technology improvements
have the potential to reduce the costs of VAM oxidation
technology, making more of the potential abatement
economically feasible for mine operators.
Degasification technologies and on-site gas use for
coal drying can provide abatement at below costs
of $0/tCO2e, representing savings or a potential
revenue stream, but only 20 MtC02e of cost-effective
abatement is available, which represents only 3% of
baseline emissions. For costs greater than $0/tCO2e,
degasification technologies contribute 16% of the total
annual abatement potential.
In 2030, China, Russia, and the United States have the
highest abatement potential for coal. China alone
represents 69% of the global mitigation potential
in coal mining, while Russia and the United States
represent 6% and 5%, respectively.
14
Global Non-C02 Greenhouse Gas Emission Projections & Mitigation: 2015-2050 15

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Natural Gas and Oil Systems
Production, Transmission, Distribution, Refining
Source Background
CH4 is the principal component of natural gas and is emitted
during natural gas production, processing, transmission, and
distribution. Oil production and processing upstream of oil
refineries can also emit CH4 in significant quantities as natural
gas is often found in conjunction with petroleum deposits. In
both systems, CH4 is a fugitive emission from leaking equipment,
system upsets, deliberate flaring and venting at production
fields, processing facilities, natural gas transmission lines and
compressor stations, natural gas storage facilities, and natural gas
distribution lines.
Historical Trends
Between 1990 and 2015, global CH4 emissions from natural gas
and oil systems increased by an estimated 15%. African and
Middle Eastern countries have been major contributors to this
increase as both regions have nearly doubled emissions during
this time. Over this same period, world natural gas production
increased about 70% and oil production increased 33%. In recent
decades, there have been numerous oil and gas initiatives aimed
at reducing emissions. The fact that production has grown faster
than emissions indicates that average rates of CH4 emissions per
unit of oil and gas production have decreased as a result of past
efforts to reduce CH4 emissions from this source.
2030 Emissions by Gas and Subsource
Oil production constitutes the1 bulk of emissions at
approximately 66%.M
Gas
Subsource
100
CH4(100%)
Oil Refining (0%)
GasTSD (10%)
Gas Production (24%)
Oil Production (66%)
Projected Emissions &Top Emitting Countries
Emissions (MtC02e)
From 2015 through 203(3,. emissions are
projected to fncreass by about 8% to
approximately 1,784 MtCOse in 2030,
2,117
1,784
1,660
1 449 1,375
1990 2000 201 5 2 0 3 0 2050
Emissions (MtC02e)
2030 Emissions from Top 5 Emitting Countries
Rest of World: 677 MtC02e

%
Top 5 Emitters
Russia
Uniied States
Iran
Uzbekistan
vCanada
16
Key Points
• Natural gas and oil systems account for 14% of total
global anthropogenic non-C02 GHG emissions in
2030.
•	Increasing emissions correspond to projected
increases in natural gas and oil production volumes.
•	Generally, the International Energy Outlook projects
increasing production, which constitutes the bulk of
emissions from all operations. As such, top emitting
country estimates increase steadily through 2030.20
Projected Trends
From 2015 through 2030, CH4 emissions from natural gas
and oil systems are projected to increase by about 8%
under the BAU scenario.21,22 This projection corresponds
to increases in natural gas (+7%) and oil production
(+19%) based on ElA's International Energy Outlook
Reference Case scenario.23
In 2030, the top 10 emitting countries comprise
approximately 73% of global emissions. Four of these
top emitters rank within the top 10 in total oil and gas
production in both 2015 and 2030, which contributes to
higher emissions. By 2030, Russia contributes the most
emissions globally from natural gas and oil systems. With
known large reserves of oil and gas and a general lower
quality of infrastructure, Russia's emissions are expected
to increase. In the United States, advances in production
technology have allowed exploitation of vast shale gas
reserves, increasing production volumes substantially.
Oil production is expected to increase in the United States
and Canada because of expanded use of enhanced oil
recovery and unconventional production such as from
oil sands. Increasing consumption of natural gas also
contributes to future increases in emissions from natural
gas and oil systems.
Current emission calculations are based on the quantity
of oil and gas production and consumption. However,
leakage and venting do not necessarily increase linearly
with throughput, and newer equipment tends to leak
less than older equipment. More accurate estimation
methodologies would make use of counts of equipment
and country-specific emission factors, but such
information is not readily available for many countries.
Even when more accurate methodologies are used,
estimates for this source have significant uncertainty.
Disaggregated results are discussed in the following
section. The disaggregated results here are based on
default emission calculations. Subsource emissions
were disaggregated by using the proportion of
each segment's emissions determined using default
calculations for that country based on production and
consumption volumes and IPCCTier 1 emission factors.24
Although in some cases country-reported disaggregated
results may be available, country-reported data at the
subsource level were not incorporated in this analysis.
Global Non-C02 Greenhouse Gas Emission Projections & Mitigation: 2015-2050 17

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Gas Production and Processing
Gas production and processing is associated with
the withdrawal and subsequent processing of
underground raw natural gas. Emission estimates
are based on the amount of natural gas produced
within each country and an aggregated IPCC emission
factor. These results have a relatively large impact on
overall results. Generally, gas production is projected
to increase globally. Particularly in countries such as
Australia, China, and Brazil, natural gas production is
expected to increase by over 40% between 2015 and
2030 according to EIA. These increases are expected
to result in higher global emissions, despite declining
production across European countries.
Gas Transmission, Storage, and Distribution
Emissions for gas transmission, storage, and
distribution are associated with the downstream
transportation of pipeline-quality gas from the
processing facility to either storage or for customer
usage. Emission estimates are based on the quantity of
gas consumed within each country and an aggregated
IPCC factor. Downstream emissions represented in
this disaggregation do not have as large an impact
on overall results as gas or oil production. Globally,
gas consumption is expected to increase. Specifically,
China is expected to be a major natural gas consumer
in future years. Despite increasing production rates
within the country, demand is expected to outpace
production. Other major natural gas-producing
countries such as Qatar, Australia, and the United
States are already competing to align themselves with
the ability to provide long-term supplies of natural
gas to China to meet record expected demand. Other
countries in Asia and the Middle East are also expected
to increase gas consumption from 2015 through 2030,
thereby increasing overall emissions.
Oil Production
Oil production is the largest contributing segment to
emissions from natural gas and oil systems and has the
most noticeable impact on overall results. Emissions
from oil wells originate from on-site operations either
associated with the direct withdrawal of oil or from the
on-site processing equipment used. Emission estimates
are based on the quantity of oil produced within each
country and an aggregated IPCC factor. This segment is
the most influential due to high IPCC emission factors
for oil production. Similar to natural gas production,
oil production is expected to increase globally from
2015 through 2030. Middle Eastern and African
countries are projected to increase oil production from
18
Natural Gas and Oil Systems
Production, Transmission, Distribution, Refining
2015 through 2030. With the emergence of hydraulic
fracturing technologies, the United States is currently
producing oil at record high volumes. Projections
expect production increases to continue. Thus, global
emissions are also expected to rise over time.
Oil Refining
Emissions in this segment are caused by equipment
fugitive leaks and vented emissions from certain
maintenance processes associated with the processing
and refining of raw crude within oil refineries such
as blowdowns. Because most of the contained CH4 is
removed from crude oil by the time of delivery to the
refinery, CH4 emissions from this segment are generally
minor. Given this (as is also represented by the low
aggregated IPCC factor), emissions from this segment
have minimal impact on overall results. Emissions from
oil refining are driven by oil consumption, which is
expected to gradually increase from 2015 through 2030
globally.
IPCC Emission Factor Sensitivity Analysis
The EPA reviewed three additional cases of results
to examine the impact of three ranges provided for
certain IPCC emission factors. The three ranges—high,
low, and geometric average—were applied to the
aggregate IPCC emission factors used to calculate Tier 1
estimates to investigate the impact of the different
factors on overall emission estimates. A particular
IPCC factor did not vary between cases if a range was
not provided. As expected,Tier 1 emission results are
higher using the upper range and lower using the
lower range. The low case Tier 1 emission results are
closest to the EPA's composite emission results, as
country-reported estimates are generally lower than
that determined using IPCC factors. The geometric
average case also did not vary much with the primary
results based on an aggregate factor using the direct
average of the range.
The following table lists overall emission results varying
for each of the cases. This overall result is a combination
of Tier 1 calculations and UNFCCC country-reported
emission estimates and can vary based on several
factors such as trends in country-specific production or
consumption. The low case varied the most from the
aggregate case, mainly due to a substantial drop in the
gas production subsource.
Comparison of Emission Factor Approaches
Emission Factor Approach
2030 Global Emission
Estimate (MtC02e)
Aggregate (chosen emission
factor for projectionsp
1,784
Case 1: High
1,878 (+5.3%, average)
Case 2: Low
1,656 (-7.2%, average)
Case 3: Geometric Average
1,706 (-4.3%, average)
a Aggregate emission factors represent the average of the IPCC
emission factor ranges used to generate results.
While having an impact on overall emission results, the
revised IPCC ranges also vary the disaggregation of
emissions based on Tier 1 estimates. As oil production
and gas production are the most influential segments
on emissions, varying the ranges of these aggregate
IPCC factors noticeably impacts segment emissions.
The gas production segment experiences the most
discernable impact from the change in ranges, as the
low case is substantially lower than the aggregate case.
Actual future emissions may differ from these
projections for several reasons. Efforts are underway
to modernize gas and oil facilities in Russia and many
Eastern European countries, which could help reduce
fugitive emissions. In areas where gas production is
projected to increase, emissions wili not necessarily
increase at the same rate. As the world becomes more
concerned with the emission of GHGs, new legislation
and voluntary carbon markets are developing to
increase energy production efficiency in the natural gas
and oil industry.
"Projected increases in natural gas and oil
production and consumption volumes across
many countries are expected to contribute to
higher future emissions."
Global Non-C02 Greenhouse Gas Emission Projections & Mitigation: 2015-2050 19

-------
Key Points
•	The global abatement potential from natural
gas and oil systems is 684 MtCQ2e, roughly
38% of baseline emissions in 2030.
•	The abatement potential at cost-effective
prices ($0/tC02e) is estimated to be 12%
of the natural gas and oil baseline in 2030,
rising to 23% at prices below $20/tC02e.
•	Available abatement measures in the natural
gas and oil production segment account
for up to 38% of total abatement potential
from natural gas and oil systems.
Abatement Measures
in total, this analysis evaluated 28 abatement
measures for their potential to mitigate CH4
emissions associated with the four natural
gas and oil system segments—production,
processing, transmission, and distribution.
Abatement measures documented by the
EPA's Natural Gas STAR Program served
as the basis for estimating the costs of
abatement measures used in this analysis.25
Measures typically fall into three categories:
equipment modifications or upgrades;
changes in operational practices, including
directed inspection and maintenance
(DI&M); and installation of new equipment.
Abatement measures are available to mitigate
emissions associated with a variety of system
components, including compressors, engines,
dehydrators, pneumatic controls, pipelines,
storage tanks, wells, and others.
DI&M programs present mitigation
opportunities across all segments of natural
gas and oil with no up-front capital costs
and high technical effectiveness, in some
cases unlocking a 95% reduction in targeted
emissions. Installing plunger lift systems in
gas wells has a small capital cost and technical
effectiveness of only 40%, but they generate
an annual revenue stream from captured gas
in excess of the initial capital costs, resulting in
a payback period of less than 1 year. Replacing
wet seals with dry in centrifugal compressors
also generates revenue but has much higher
capital costs and a longer payback period.
The most expensive mitigation options
considered in this analysis are open flaring in
offshore platforms and replacement of aging or
unprotected pipeline infrastructure.
Reductions at
No Cost
Technically Feasible
at Increasing Costs
Residual
Emissions
Reduction Potential by Technology
In 2050, installing vapor recovery unit-son oil storage tanks is the> leading emission
abatement measure and presents the largest abatement potential at prices below
¦$Q/tC0'sa This technology contributes'Pfr'-gf potential abatement in 2030.
1+1 Canada
$100 1-
-$20
200 0
V-
Rest of World
Directed Inspection and Maintenance |
Installing Vapor Recovery Units on Oil Storage
Tanks I
Flaring Instead ofVenting on Shallow Water
Platforms
Convert Gas Pneumatic Controls to Instrument Air
Installing Catalytic;Converters on Gas Engines and
Turbines
Fuel Gas Retrofit for BD Valve - Take Recip.
Compressors Offline
Replacing High-bleed Pneumatic Devices in the
Natural Gas Industry
Installing Plunger Lift Systems in Gas Wells
Replace Cast Iron Pipeline
Replacing Wet Seals With Dry Seals in Centrifugal
Compressors
Reciprocating Compressor Rod Packing (Static-Pac)
Using a Portable Evacuation Compressor for
Pipeline Blowdowns
Other Measures
50
150
100
MtC0.e
Reductions achievable at costs less than $0/tC02e
Reductions achievable at costs greater than $0/tC02e
200
Abatement Potential
In 2015, the global abatement potential from natural
gas and oil systems was 508 MtC02e, or 31% of total
emissions from this source. The abatement potential is
projected to increase over time to 684 MtC02e in 2030,
respectively, representing 38% of total emissions.
In 2030, abatement measures could reduce emissions
by 23% at break-even prices of $20 or below. However,
in 2030,37% of potential abatement is estimated to
cost more than $50/tCO2e, suggesting that achieving
these reductions would be difficult without reducing
the cost of abatement or improving the removal
efficiency of available abatement measures.
At the global scale, the two measures with the highest
abatement potential, respectively, are using DI&M and
installing vapor recovery units on oil storage tanks. In
2030, using DI&M potentially can reduce 52 MtC02 at
below $0/tCO2e and 130 MtC02 at costs above $0/tCO2.
Installing vapor recovery units can achieve 67 MtC02e
at below $0/tCO2e and 34 MtC02e at costs above
$0/tCO2.
At a country scale, Russia (204 MtC02e), the United
States (135 MtC02e), and Iran (43 MtC02e) have the
highest abatement potential in 2030. DI&M is the
leading abatement option in the United States and
Iran, capturing 39% and 21 % of national abatement
potential, respectively. At break-even prices below
$0/tCO2e, DI&M offers 28 MtC02e and 2.5 MtC02e of
abatement for the United States and Iran, respectively.
In Russia, installing vapor recovery units on oil storage
tanks and using DI&M contribute to 24% of national
abatement potential.
Total Reduction Potential
Reducing emissions by 8% compared with the 2020 baseline fe CDst-effectite,
An addltiunalifpf red action is available using technologies with increasingly
higher costs.The cost-effective reduction potential rises to }!% in 2030 and
18%.in 2650.
Baseline: 1,684 MtCO,e .
Baseline: 1,784 MtCO,e ¦
Baseline: 2,117 MtCO e
Marginal Abatement Cost Curves, 2030
In 2030, Russia has: the highest emissions from natural gas and oil systems and contributes to 32%oftheglobal abatement
potential from this source. The top 5 countries by emissions, represented: bythe figures below, make up 61% of total potential
abatement from this source globally.
Uzbekistan
United States
20
Global Non-C02 Greenhouse Gas Emission Projections & Mitigation: 2015-2050 21

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Combustion of Fossil Fuels and Biomass
CH4 and N20 Emissions from Combustion
Source Background
CH4 and N20 emissions result from the combustion of fossil
fuels and biomass26 in both stationary and mobile sources.27
CH4 emissions are primarily a function of the CH4 content of the
fuel and the overall combustion efficiency. N20 emissions vary
according to the type of fuel, combustion technology, size and
vintage (model year for mobile combustion), pollution control
equipment used, and maintenance and operating practices.
Although fossil fuels are used as the primary energy source
in most countries, biomass is an important energy source in
developing countries where it is primarily used in small-scale
combustion devices for heating, cooking, and lighting purposes.
Historical Trends
Between 1990 and 2015, CH4 and N20 emissions from fuel
combustion increased by 36% as total fuel consumption increased
by 53% on a BTU basis.28,29 Global trends in fuel consumption
are largely related to historical trends in energy demand.
Global demand for electricity has increased, which resulted
in an increase in the use of fossil fuels and biomass for power
generation. Emissions from fossil fuel combustion in stationary
and mobile sources increased by 57% from 1990 through 2015,
while emissions from biomass combustion increased by only 7%
over this time period. Fossil fuels have continued to dominate as
the primary energy sources over non-fossil alternatives such as
biofuels, waste energy, and traditional forms of biomass (i.e., wood
fuel and charcoal).
Projected Emissions &Top Emitting Countries
2030 Emissions by Gas, Subsource,
and Fuel Type
CH^missions are projected to continue to make up the
largest portion ofcombustiqh emissions by gas, increasing
from' 62% of total combustion emissions in 1990 to 67% in
2G3ffl. Fossil fuels are also projected to continue'to make up
the majority ofeombustlon emissions, increasing from 59%
of total combustioh emissions in 1990 to 7296 in 2Q3
-------

INDUSTRIAL
Introduction
The industrial processes sector is the fourth largest
contributing sector to global emissions of non-C02
GHGs, accounting for 10% of emissions in 2015. This
section presents global N20 and F-GHG (SF6, PFCs,
SF6, and NF3) historical and projected emissions and
mitigation potential from the industrial processes sector.
F-GHGs are important because the gases tend to have
large heat-trapping capacities and long atmospheric
lifetimes. The sources covered in the chapter include the
following categories:
•	Nitric and adipic acid production (N20)
•	Electronics (HFCs, PFCs, SF6, NF3)
•	Electric power systems (EPS) (SF6)
•	Metals (PFCs, SF6)
•	Substitutes for ozone-depleting substances (ODSs)
(HFCs)
•	HCFC-22 production (HFCs)
Projections and MAC curves were estimated for all
sectors. These sources represent 94% of the total non-
C02 GHG emissions in 2015 from the industrial processes
sector.
Emissions from the industrial processes sector increased
145% between 1990 and 2015. ODS substitutes and
HCFC-22 production were the largest sources of
emissions in the industrial processes sector in 2015,
comprising 56% and 12% of emissions, respectively.
Nitric and adipic acid production accounted for 37%
of non-C02 emissions from the sector in 1990 and
decreased to 14% in 2015 because of the widespread
installation of abatement equipment.
As the fastest growing sector, industrial processes'
emissions are projected to increase 76% between 2015
and 2030 under a BAU scenario, reaching 2,202 MtC02e
Emission Reduction Potential, 2030
in 2030. Emissions from ODS substitutes and HCFC-22
production are projected to increase 106% and 10%
between 2015 and 2030, respectively. Emissions from
ODS substitutes (HFCs) are projected to increase rapidly
because of the phaseout of ODSs under the Montreal
Protocol and strong predicted growth in traditional ODS
applications (e.g., ref/AC). Although some countries have
ratified amendments to the Montreal Protocol whose
implementation would result in lower emissions, the
BAU projections included here do not assume reductions
from those amendments.
Historical and Projected Emissions from the
Industrial Processes Sector
3,500
3,000
<5 2,500
2,000
q 1,500
£ 1,000
1990 2000 2015
Metals
Other Industrial
¦ EPS	|
Electronics
2030 2050
HCFC-22
Nitric and Adipic
ODS Substitutes
Mitigation potential from the industrial processes sector
is estimated to be approximately 1,060 MtC02e in
2030. This mitigation potential is 55% of the industrial
processes sector's emissions and 28% of total global
non-C02 mitigation potential in that year.
Baseline: 2,202 MtC02e	
Reductions at No Cost
Technically Feasible at Increasing Costs
Residual Emissions
Global Non-C02 Greenhouse Gas Emission Projections & Mitigation: 2015-2050 25

-------
Nitric and Adipic Acid Production
Source Background
Nitric acid is an inorganic compound used primarily to
make synthetic commercial fertilizer. Adipic acid is a white
crystalline solid used as a feedstock in the manufacture of
synthetic fibers, coatings, plastics, urethane foams, elastomers,
and synthetic lubricants. The production of these acids results
in N20 emissions as a by-product.
Historical Trends
N20 emissions from nitric and adipic acid production
decreased by 28% between 1990 and 2010. However,
emissions increased by 27% between 2010 and 2015. Over
the entire historical period, the production of both acids
increased. Despite the production increase, emissions
have historically declined due to worldwide installation of
abatement technologies in the adipic acid industry.37 As
of 2016, most producers of adipic acid had implemented
abatement technologies, but less progress has been made
in abating emissions from nitric acid plants.38This analysis
incorporated abatement to the extent that emission
reductions are reflected in country-reported data. In addition,
this analysis incorporated known bio-based adipic acid
capacity until 2007, after which the capacity was maintained
at a constant levei.39The upward trend in emissions between
2010 and 2015 is primarily a result of an increase in adipic acid
production without N20 abatement in China.40,41
By 3Q30, about Mo-thirds of NiO emissions from thissource
category are projected to be from adipicaqd production
compared with about one-third from nitric acid productions®
2030 Emissions by Gas and Subsource
Subsource
N2O(100%)
Nitric (34%)
Adipic (66%)
Projected Emissions &Top Emitting Countries
Emissions (MtC02e)	2030 Emissions from Top 5 Emitting Countries
From 201,8throug h 2030; globa I N20	Rest of World: 37 MtC02e
emissions from nitric acid and adipic,
5Cid production are projected to!
increase by 5S%

483
m.

Top 5 Emitters
15
1990 2000 2015 2 0 3 0 2050
Emissions (MtC02e)
China
United States
Singapote
Egypt
' Russia
Key Points
>	While nitric and adipic acid production increased
at an annualized rate of 1% globally between 1990
and 2015, N20 emissions from production decreased
by 9%, primarily due to worldwide installation of
abatement technologies in the adipic acid industry.
>	Global N20 emissions from nitric and adipic acid
production are projected to increase by 55% between
2015 and 2030, driven by projected high growth in
adipic acid demand.
>	Emission projections from adipic acid production
incorporate fixed historical emission control.
Projected Trends
Because a small number of countries produce nitric and
adipic acid, the top 5 emitting countries comprise 86% of
global emissions in 2030. China is expected to contribute
the most emissions from nitric and adipic acid production
by 2030, followed by the United States and Singapore. Key
factors influencing the overall increasing trend from 2015
through 2030 include (1) high projected growth in the
global demand for adipic acid, (2) increasing emissions
from production in China, (3) decreasing proportion
of emissions from OECD countries due to decreasing
proportion of production in OECD countries, and (4)
capacity expansions to meet increased global demand
for adipic acid in Asia, while market restructuring from
reduced consumption and market saturation in Western
Europe and North America/^
Emissions from nitric acid production are estimated to
increase by 17% between 2015 and 2030, which aligns
with the estimated 16% growth of nitric acid production.
Emissions are projected based on estimated long-term
nitrogenous fertilizer consumption, broken out by world
regions for 2015 through 2030.44 Literature suggests
that to meet projected food demand the production
of nitrogenous fertilizer will increase between 70%
and 100% by 2050 compared with 2000 production.45
N20 abatement in nitric acid plants is rarely
implemented without incentive programs; therefore,
this analysis did not assume that any abatement
technology was already installed .46 Fertilizer production
and consumption are expected to continue to increase
in Asia and decline in Europe and North America .47 The
decline is due in part to strict regulations stemming from
concerns about nitrates in the water supply.
From 2015 through 2030, emissions from adipic acid
production are estimated to increase by 86%, which
aligns with the estimated 87% growth of adipic acid
production. Emission projections incorporate fixed
historical emission control, which includes historical
bio-based adipic acid production and N20 emission
abatement to the extent that emission reductions are
reflected in country-reported data. The main driver for
the projections is the BAU assumption that global adipic
acid consumption will increase by 3.5% annually from
2015 through 2030, based on the consumption growth
rate for the period 2008 through 2013. The growth rate
of 3.5% was used because it reflects the average of the
range of growth rate projections in the literature.48,49,50,51
Global Non-C02 Greenhouse Gas Emission Projections & Mitigation: 2015-2050 27

-------
Key Points
• The global abatement potential is
231 MtC02e, or 86% of projected emissions
in 2030.
•	All mitigation potential for this source
category comes at a cost higher than $0
MtC02e. A 69% reduction in emissions is
achievable at prices below $20.
•	Facility design constraints and/or operating
costs drive abatement measure selection.
Thermal destruction is the technology with
the most mitigation potential.
Abatement Measures
To estimate abatement potential for this analysis,
we used a modified version of the projected
emissions.This revised baseline projection
assumes a higher N20 emissions from nitric acid
production and a smaller share of emissions
attributed to adipic acid production.
This analysis considered four abatement
measures applied to the chemical process used
to produce nitric and adipic acid to reduce
the quantity of N20 emissions released during
production. Three abatement measures—
catalytic decomposition, catalytic reduction,
and homogeneous decomposition—were
modeled for nitric acid production. Catalytic
decomposition and reduction can be
applied as tertiary measures. Catalytic and
homogeneous decomposition are considered
secondary processes, which are applied inside
or immediately following the ammonia burner.
Homogeneous decomposition is better suited
for new facilities because of the associated
design changes and capital costs. Some primary
measures, which are applied at the beginning of
the production process to prevent the formation
of N20, exist, but they were not modeled in this
analysis because of data limitations.
Adipic acid facilities direct the flue gas to a
reductive furnace in a thermal destruction
process to reduce nitric oxide (NOx) emissions.
Thermal destruction is the combustion of
off-gases (including N20) in the presence of
CH4.The combustion process converts N20 to
nitrogen, resulting primarily in emissions of NO
and some residual N20.52 The heat generated
from this process can also be used to produce
process steam, offsetting more expensive steam
generated using just fossil fuels.
Total Reduction Potential
There are1 no.emi$sion reductions available in nitricand adipic acid production
at prices below $t)/tCOj€, $t increasing gosts. an 81% reduction in emissions is
aVailabltin 202Q.Thf ^mission reduction potential at increasing costs rises to
86%in 2630 and to 88% in 2050.
Baseline: 201 MtCO,e
Baseline: 270 MtCO,e
Baseline: 483 MtCO,e
Reductions at
No Cost
12%
2020
2030
2050
Technically Feasible
at Increasing Costs
Residual
Emissions
Reduction Potential by Technology
In 2(330, thermal destruction is the leading emission abatement measure with
,52 MtCGie, though all abatement measures offer at least 39 MtCOje of potential
abatement There is no potential abftement below a price of $0/teOj&'
Thermal Destruction
Non-selective Catalytic Reduction
Tail-gas Catalytic Decomposition
Catalytic Decomposition in the Burner
Homogeneous Decomposition in the Burner
10 20 30 40 50 6
MtC02e
Reductions achievable at costs less than $0/tC02e
Reductions achievable at costs greater than $0/tC02e
28
Nitric and Adipic Acid Production
Marginal Abatement Cost Curves, 2030
Taken together, the top 5 countries in terms of baseline emissions represent 85% of all potential global abatement in the source
category in 2030. China alone represents 67% of total abatement potential, in part because of its high production capacity and
lower adoption of emission controls relative to other large producers of nitric and adipic acid.
China
$100 r
$80
$60
$40
$20
$0
-$20
$100
Egypt
United States
$100
-J
90 120 150 180 0 30
Russia
$100
$80
$60
$40
$20
$0
-$20
Singapore
©
60 90 120 150
Rest of World
$100
$100
$60 -
$40 -
$20 -
$0 -
-$20
$60 -
$40 -
$20 -
$0 '
-$20
$60 -
$40 -
$20 -
$0 '
-$20
-$40
60 90 120 150
Abatement Potential
The global emission reduction potential in the nitric and
adipic acid production source category is 231 MtC02e
in 2030, or 86% of projected baseline emissions from
nitric and adipic acid production. Roughly 80% of the
abatement potential is achievable at break-even prices
between $0 and $20, demonstrating that low break-
even prices can have a substantial impact on reducing
emissions from this source category.
In 2030, the top 3 mitigation technologies at the
global level are thermal destruction, tail-gas catalytic
decomposition, and nonselective catalytic reduction.
The top 3 technologies contribute to 64% of the global
mitigation potential. Thermal destruction, the top
technology, contributes to nearly a quarter of the source
category's overall potential.
At the country level, China, the United States, and
Singapore are the largest emitters in this source
category, making them the largest potential sources
of abatement as well. The top 3 countries combined
contribute to 80% of the global abatement potential in
2030, or 184 MtC02e. China alone causes over 65% of
emissions from nitric and adipic acid production but also
contributes to 67% of the global abatement potential.
China and the United States can reach 61 % and 49% of
their national abatement potential at break-even prices
below $10/tCO2e.
Although a comprehensive inventory of nitric acid
production facilities is not available, adipic acid
production is more clearly characterized. In the 1990s,
most of the adipic acid producers in developed countries
voluntarily adopted N20 abatement measures.53,54,55 in
2005, with the establishment of the Clean Development
Mechanism (CDM) methodology for crediting N20
abatement projects at adipic acid plants, producers in
developing countries began to adopt N20 abatement
measures. As of 2010,85% of the adipic acid production
capacity globally already had N20 emission controls in
place. Of the remaining 15% uncontrolled capacity, 12%
resides in China, and the rest is distributed between
Japan, Ukraine, and India.
Global Non-C02 Greenhouse Gas Emission Projections & Mitigation: 2015-2050 29

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Electronics
Semiconductor, FPD, and PV Manufacturing
Source Background
Electronics consists of emissions from the manufacturing of
semiconductors, flat panei displays (FPDs), and photovoltaics (PV).
During the manufacture of these electronics, F-GHGs, including
HFCs, PFCs, SF6, and NF3, are emitted from two repeated activities:
(1) cleaning of chemical vapor deposition chambers and (2) plasma
etching (etching intricate patterns into successive layers of films
and metals).
Historical Trends
Between 1990 and 2015, emissions from electronics manufacturing
increased by 519%. During the same time frame, semiconductor
manufacturing emissions increased by 149%, because of rapid
growth in demand for electronics. Emission growth would have
been larger without the application of abatement measures and
country-and global-level reduction agreements.
Emissions from FPD manufacturing increased by over 12,000%
between 1990 and 2015. Underlying this growth in emissions from
electronics manufacturing, FPDs have grown from a very small
portion to over half of the electronics display market.
Because of the nascence of the PV industry before 2005, emissions
from PV manufacturing were only estimated after 2005. From 2005
through 2015, emissions from PV manufacturing increased by over
2,000%. The increase in emissions from PV manufacturing is due
to growth of the PV industry from a nascent to mature industry as
demand for renewable sources of energy has increased.
2030 Emissions by Gas and Subsource
I ft 2830, FPD ma n ufactu ring Is projected' toeontri bute
nearly'65§6;of emissions from this category, followed by
semiconductor manufacturing Q298} and PV manufacturing
0%). In 2030i.emissionS from are projected to represent
approximately 188 of emissions from this category followed
by PFCs (llfsl NFjflfj®, and FlFCs©#).
100
Gas
Subsource
HFCs (3%)
NF3 (17%)
PFCs (22%)
SF6 (58%)
PV (3%)
Semi (32%)
FPD (65%)
Projected Emissions &Top Emitting Countries
Emissions (MtC02e)
From 2®II through 2Q30>F-GHG
emissions from electronics
man ufactu ring are projected to increas#
by 80%.
2030 Emissions from Top 5 Emitting Countries
Rest of World: 5 MtC02e

182
51
8
25
¦




3 Top 5 Emitters
china
South Korea
United States
¦ Singapore
Japan
1990 2000 2015 2 0 3 0 2050
Emissions (MtC02e)
Key Points
• From 1990 through 2015, emissions from electronics
manufacturing increased by 519% because of the
rapid growth in the demand for electronics.
From 2015 to 2030, emissions are estimated to
increase by 80%, driven by increased demand for
electronics and the increasing market share of FPDs.
Emissions from PV manufacturing are expected to
decrease between 2015 and 2030 because of the
slowed growth in global installed solar generating
capacity, though these estimates depend heavily on
country-level policies, which may change significantly
in thefuture.56
Projected Trends
From 2015 through 2030, emissions from FPD
manufacturing are estimated to triple. This projection
assumes large growth in the FPD industry, tapering
from an assumed annual growth rate of about 9% from
2015 through 2025 to about 4% from 2025 through
2050. Long-term industry forecasts show continued
growth in demand57 driven by demand for larger
displays, but growth is expected to slow down after
2025, with the maturity of FPD applications and a
slowing trend toward larger size screens.ss
From 2015 through 2030, emissions from
semiconductor manufacturing are estimated to
increase by 46% primarily because of the increased
demand for electronic goods. The projected emission
results continue to be driven by emissions from China,
whose country share grows from its historical status of
about 30% of global emissions in 2015 to closer to 50%
by 2030.
Manufacturing capacities are projected to increase
at a rate equivalent to the growth in each country's
gross domestic product. Gas shares by country
(e.g., percentage of a country's semiconductor
manufacturing emissions that are a certain gas, such
as SF6) were calculated from the historical reported
emissions of total semiconductor emissions. These gas
shares were held constant from 2015 through 2030
to determine country emissions by type of gas. Gas
shares may be affected by advancements in abatement
technology, but these projections maintain the gas
shares as constant because of the inability to predict
these changes.
Projected emissions from the solar PV industry
decrease by 72% from 2015 through 2030. Projected
emissions are expected to drop drastically in 2020 (58%
decrease from 2015) and 2025 (42% decrease from
2020) and then become relatively more stable from
2030 through 2050. Decreasing trends in emissions
are a result of a slowed growth rate in installed solar
capacity (i.e., the incremental change in the installed
solar generating capacity). The projected world
installed solar generating capacity is expected to grow
by 44.5 gigawatts (GW) in 2015 but only by 19.5 GW
in 2016 (and then fluctuates between 10.4 GW and
19.5 GWfrom 2016 through 2040).59 However, these
estimates depend heavily on changes in country-level
policies; what these policies will look like and how they
will be implemented are still unknown.^
Global Non-C02 Greenhouse Gas Emission Projections & Mitigation: 2015-2050 31

-------
Key Points
• The global abatement potential for the
electronics source category is 51 MtC02e, or
56% of baseline emissions, in 2030.
• Mitigation potential from FPD
manufacturing has the greatest reduction
potential at 41 MtC02e in 2030,44% of
baseline emissions.
• Reducing emissions from these sources
is expensive: break-even prices below
$20/tC02e can achieve only a 1% reduction
in baseline emissions.
Abatement Measures
Abatement measures can be applied in the
electronics source category throughout
processes for the manufacturing of
semiconductors, FPDs, and PVs.This analysis
considered eight abatement measures across
the two manufacturing processes: central
abatement, thermal abatement, catalytic
abatement, plasma abatement, catamal
abatement, NF3 remote chamber cleaning, gas
replacement, and process optimization. These
technologies reduce emissions from either etch
or chamber-cleaning processes (or in some
cases both). The measures focus on reducing
F-GHG (i.e., HFCs, PFCs, SF6, or NF3) emissions
that are released during production.
Across the technologies used in the electronics
manufacturing industry, thermal abatement,
NF3 remote chamber cleaning, and catalytic
abatement tend to have the highest market
penetration, meaning that manufacturers are
implementing these abatement technologies
most often. These technologies have high
reduction efficiencies. Thermal abatement and
NF3 remote chamber cleaning have a reduction
efficiency of 95%, while catalytic abatement
has a reduction efficiency of 99%. Both thermal
and catalytic abatement destroys or removes
F-GHGs from effluent process streams; one uses
heat and the other uses catalysts (e.g., CuO,
ZnO, Al203). Thermal and catalytic abatement
technologies have a lifetime of approximately
7 years. In contrast, a facility can use NF3 remote
chamber cleaning between 21 and 25 years
before needing replacement.
Total Reduction Potential
Reducing emissions by 2% compared with the 2Q20 baselineIs eost-efffectite
(below SO/tGOge). An additional 5B% reduction Is available .using.'te£hno|pgtes
With increasingly higher colts,-
Base ine:60 MtCO,e
Baseline: 92 MtCO,e
Baseline: 182 MtCO,e-
42%
2020
2030
2050
Reductions at
No Cost
Technically Feasible
at Increasing Costs
Residual
Emissions
Reduction Potential by Technology
in 2030, no abaWnent Is available below $0/tCC%®. For costs greater than
SO/tGOjg, therma | abatement Is the leading emission abatement msasune with
the potential to reducesmissions by 32 MKQp in 203Q.
Thermal Abatement I
NF3 Remote Clean I
Catalytic Abatement I
Gas Replacement j
Central Abatement System |
Plasma Abatement |
Catamal Abatement j
Process Optimization
5
10
25
30
15 20
MtC02e
Reductions achievable at costs less than $0/tC02e
Reductions achievable at costs greater than $0/tC02e
35
Marginal Abatement Cost Curves, 2030
Taken together, the top 5 countries in terms of baseline emissions represent 96% of all potential global abatement in the
electronics source category in 2030. China is the highest emitting country but also contributes to 55% of global abatement
potential for the category, or 28 MtC02e, in 2030.
China
$ioo -
$80 -
$60 -
$40 -
$20 "
$o
-$20
j
South Korea
United States
$100
$80
$60
$40
$20
$o
r
-$20
15	20 0
$100 -
$80 -
$60 -
$40 -
$20
$0
-$20
F
$100
$80
$60
$40
$20
$0
-$20
r
Singapore
$ioo —
Rest of World
Abatement Potential
Abatement potential in the electronics source category
is estimated to be 51 MtC02e, 56% of the baseline
emissions. Implementing abatement measures in the
electronics source category is costly At break-even
prices below $20/tCO2e, only 1 % of baseline emissions
can potentially be abated in 2030, which is equal to 2%
of the annual potential abatement.
FPD manufacturing has the highest abatement
potential followed by semiconductors and PV. The
technologies with the highest abatement potential
are thermal abatement and NF3 remote chamber
cleaning, which have the potential to mitigate 32
MtC02e and 8 MtC02e, respectively, at costs greater
than $0/tCO2e. Thermal abatement constitutes 62%
of the abatement potential, and NF3 remote chamber
cleaning contributes to 17%. Installing these abatement
technologies requires high initial capita! costs and
annual maintenance costs. As a result, emission
reductions from the electronics source category are
not cost-effective. For example, installing thermal
abatement measures costs $6.3 million and has annual
maintenance costs of $360,000.
China, South Korea, and the United States have the
highest abatement potential in the electronics source
category in 2030. China has the potential to abate
28 MtC02e, which is 55% of the global abatement
potential. South Korea's abatement potential reaches
17 MtC02e followed by 2 MtC02e for the United States.
The leading abatement technologies in all three
countries follow the global trend; thermal abatement
is the number one abatement measure followed by
NF3 remote chamber cleaning. Thermal abatement
can potentially mitigate 17 MtC02e, 10 MtC02e, and
1 MtC02e in China, South Korea, and the United States,
respectively.
Global Non-C02 Greenhouse Gas Emission Projections & Mitigation: 2015-2050 33

-------
Key Points
• Overall, global SF6 emissions increased by 22% from
1990 through 2015 despite a downward trend in the
mid-1990s.
Electric Power Systems
Source Background
SF6 is used for absorption of energy from electric currents flowing
between conductors and as an insulating medium in electrical
transmission and distribution equipment (also referred to herein
as electric power systems). SF6 emissions occur through leakage
and handling losses. Manufacturing equipment for electrical
transmission and distribution also results in SF6 emissions, but this
report does not include this source.
The type and age of SF6-containing equipment and the handling
and maintenance protocols used by electric utilities affect SF6
emissions from electric power systems. Historically, approximately
20% of total global SF6 sales have been attributed to electric
power systems, where the SF6 is believed to have been used
primarily to replace emitted SF6.60% of global sales have gone to
manufacturers of electrical equipment, where the SF6 is believed to
have been mostly banked in new equipment.ei
Historical Trends
Global emissions increased by 22% from 1990 through 2015
despite a downward trend in the mid-1990s when the price of SF6
gas increased significantly, motivating electric utilities to improve
SF6 management practices. In the following decade as SF6 sales
increased, that trend was reversed. The continued increase in global
emissions occurred for all countries except for the United States,
parts of the European Union, and Japan, where voluntary efforts to
reduce emissions from electric power systems have had success.
2030 Activity Data and Emissions
In 2830, the'top Remitting/countries fflmprfse'60% of global
SFjg, emissions from electric power systems and 35% of net
electricity generation. As infrastructure expands, emissions
from developing countries are-anticipated togrowat the same
rate as country- or region-specific net electricity generation
projections.
100
Net Electricity
Generation
(Billion kWh)
Emissions
(MtCO-,e)
Top 5 Countries
(35%)
Rest of the World
(65%)
Top 5 Countries
(60%)
Rest of the World
(40%)
*Top 5 based on top 5 highest emitting countries.
Projected Emissions &Top Emitting Countries
Emissions (MtC02e)
From 20:15"through 2030,SFjemissions
from electric power systems are
estimated.to increase steadily by 3496,
2030 Emissions from Top 5 Emitting Countries
Rest of World: 31 MtC02e
107
1990 2000 201 5 2 0 3 0 2050
Emissions (MtC02e)

Top 5 Emitters
china
India
South Kcjrea
' South Africa
Saudi Arabia
Projected Trends
From 2015 through 2030, SF6 emissions from the
operation of electric power systems are estimated to
increase by 34%. Emissions from developing countries
are expected to continue to increase over the projection
period. As infrastructure expands to meet the demands
of growing populations and economies, emissions are
estimated to grow at a rate proportional to country- or
region-specific net electricity consumption, which is
projected to increase twice as fast in developing countries
between 2015 and 2030."
In contrast, in the United States and the European Union,
emissions are expected to decrease between 2015
and 2030 as utilities continue to implement reduction
measures in response to voluntary and mandatory
programs. In addition, utilities in these countries are
installing equipment with smaller SF6 capacity, helping
to minimize the potential for further emissions.
China's estimated emissions significantly contribute
to the overall increasing emission trend. China has
experienced and is expected to continue to experience
a relatively high growth rate of SF6 emissions.62,63 Fang
et al.64 estimate that approximately 70% of China's total
SF6 emissions originate from the electrical equipment
industry. While historical emissions from Fang et al. are
relatively close to the EPA's historical estimate, the study'
2020 projection diverges significantly to nearly double
the EPA's 2020 estimate.
Global SF6 emissions are estimated to increase by
34% by 2030, driven by an expected increase in
electricity usage in developing countries, particularly
China.
SF6 emissions from developed countries are expected
to decline as utilities, through ongoing involvement
in government-sponsored programs, implement
reduction measures.
34
Global Non-C02 Greenhouse Gas Emission Projections & Mitigation: 2015-2050 35

-------
Key Points
The global abatement potential for electric
power systems in 2030 is 54 MtC02e, or 70%
of baseline emissions.
The abatement potential at cost-effective
prices ($0/tC02e) is estimated to be 10% of
the electric power system's baseline in 2030,
rising to 43% at prices below $20/tC02e.
Improved SF6 handling practices during
decommissioning of electric power systems
is the leading abatement measure.
Abatement Measures
This analysis considers five main abatement
technologies and measures for the electric
power system. The first measure, SF6 recycling,
reduces emissions by technicians transferring
SF6 to special gas carts before maintenance
or decommissioning to reuse the gas. The
second measure, known as leak detection
and repair reduces emissions in a two-step
process: (1) identifying the leaks through
either a camera or a hand-held gas detector
and (2) later sealing the leak or completely
replacing the broken component. The third
measure, equipment refurbishment, is a
method that reduces longer term leakage
problems by disassembling and possibly
upgrading equipment with clean or new
components, but this abatement measure can
be costly to implement. Another abatement
measure uses a combination of different gases
to form a class of g3 mixtures that have a GWP
less than SF6. The final and most cost-effective
measure, especially in the developing world,
is improving SF6 handling. Properly training
employees to handle SF6 can reduce and avoid
instances of accidentally venting the gas; using
inappropriate fittings to connect transfer hoses
to cylinders or equipment; and misplacing gas
cylinders, which result in handling losses.
This analysis divided countries into partially
controlled and uncontrolled systems. The
United States, the European Union, and Japan
comprise the controlled system, meaning that
these nations have partially or fully adopted
the available abatement technologies. In
contrast, developing nations are categorized
as uncontrolled systems because they do not
frequently apply abatement options.
m
M

...
Total Reduction Potential
Reducing emissions byt>% compared with the 1Q2Q baseline is cost-effective,
Thecost-effecfl^a reduction potential rises to 79/t> In 2DS® arid, to:85§ in 2050,,
An additional ©If reduction is available asing technologies Vvith increasingly
higher costs (abe* $0/tCOj
-------
Metals
Aluminum and Magnesium Production
Source Background
Emissions from metal production include PFCs emitted as
by-products of aluminum production and SF6 emitted from
magnesium production.
During the aluminum smelting process, high voltage anode effect
events emit tetrafluoromethane (CF4) and hexafluoroethane (C2F6).
Recent research has shown that low-voltage anode effect events
also emit PFCs;65 however, such emissions are not accounted for in
this analysis.
The magnesium production and casting industry uses SF6 to
prevent spontaneous combustion of molten magnesium in
the presence of air. Fugitive SF6 emissions occur mostly during
primary production, die-casting, and recycling-based or secondary
production. Additional processes may use SF6; however, these
processes are believed to be minor emission sources.
Historical Trends
From 1990 through 2015, combined PFC and SF6 emissions from
metal production decreased by 68%. Emissions from aluminum
production declined by 67% as a result of global smelters
voluntarily reducing emissions through improvements in smelter
technologies and practices. From 1990 through 2015, global
emissions from magnesium production decreased by 71 %, due to
the EPA's SF6 Emission Reduction Partnership for the Magnesium
Industry, which formed a global industry commitment to eliminate
SF6 emissions from operations by the end of 2010.66
2030 Emissions by Gas and Subsource
The saft majority of emissions from metal production are
PFC emissions from aluminum production (92965, which
consist of CF4 and:Cjft#missionsvC©3 is also generated from
anocfe consumption during aluminum production, butCCh
emissions are outside the scope:of this analysis. Magnesfum
production results in Sfpemisslons.
Gas
Subsource
100
SF6 (8%)
PFCs (92%)
Magnesium (8%)
Aluminum (92%)
Projected Emissions &Top Emitting Countries
Emissions (MtC02e)
Rom 2015 through 2030, combined
emissions from metal production are
projected to almost doubld
117
1990 2000 201 5 2 0 3 0 2050
Emissions (MtC02e)
2030 Emissions from Top 5 Emitting Countries
Rest of World: 11 MtC02e
Top 5 Emitters
China
Russia
United States
United Arab Emirates
¦ Canada
38
Key Points
• Emissions from metal production are projected
to increase by 96% between 2015 and 2030, with
varying growth across emissions from aluminum
production (103% increase) and magnesium
production (40% increase).
Aluminum and magnesium production are projected
to increase by 42% and 40%, respectively, from
2015 through 2030, driving the increase in overall
emissions.
By 2030, primary production, die-casting, and
recycling are anticipated to contribute 68%, 24%, and
7%, respectively, to SF6 emissions from magnesium
production.
Projected Trends
Aluminum Production
From 2015 through 2030, emissions from aluminum
production are projected to double in the BAU scenario.
Over the projection period, the analysis assumed that
the effective emission factors (e.g., GWP-weighted
emissions per production) will remain constant at 2015
values; consequently, future emissions will be driven by
increasing aluminum production.
Country-specific production projections from 2020
through 2050 were estimated based on a global
aluminum production compounded annual growth rate
based on historical production data from 2005 through
2015.67 Future growth rates in production in individual
countries might be significantly different from the rest-of-
world rate.
From 2015 through 2030, aluminum production is
expected to grow at about 6% per year. The greatest
growth in production is expected to occur in China, where
annual aluminum production is projected to increase by
about 45,000 metric tons by 2030.
Following the achievement of its previous target in 2006,
the International Aluminium Institute (IAl) endorsed a
new voluntary target in 2008 of reducing PFC emission
intensity by at least 50% by 2020 as compared with the
2006 PFC emission intensity (equivalent to a reduction
of 93% compared with 1990). China is not expected to
participate in efforts to achieve this targets but if other
countries achieve this goal, future emissions could be
lower than the projected emissions in the BAU scenario.
Magnesium Production
Emission projections for magnesium are based on
estimates that, by 2020, the global production growth
rate of magnesium metal will be 3% per year, on
average, with the most rapid growth expected in the
die-casting industry at 4% per year.69 Die-casting
growth is anticipated to be influenced by increasing
investments by Western, Japanese, and Taiwanese
companies in China to meet their respective domestic
demand for cameras, computers, and automobile parts.
New facility construction and facility capacity expansion
Global Non-C02 Greenhouse Gas Emission Projections & Mitigation: 2015-2050 39

-------
are anticipated to meet growing global demand
for magnesium in applications such as automotive
light-weighting to improve fuel economy. Hence,
SF6 emissions are projected to steadily increase, on
average, by 3% annually from 2015 through 2030 in
response to the anticipated growth in the industry.^
Historical Aluminum Production Emissions
Historical aluminum production emission reductions
were partially offset by a doubling of global aluminum
production between 1990 and 2010.Total RFC
emissions began to increase from 2010 through 2015
as global aluminum production continued to increase,
especially in China, and efforts to reduce emissions
slowed. The IAI estimates of aluminum production
in 2015 are similar to the production estimates in
this analysis for 2015 (within 1%)7i However, the
IAI estimates lower emissions (about 30% less than
the emission estimate for 2015 in this analysis) and
may reflect more accurate information on the actual
emissions from individual facilities using a particular
electrolytic cell type.
40
Historical Magnesium Production Emissions
In the absence of emission control measures, the
rapid growth of the magnesium manufacturing
industry is expected to significantly increase
future SF6 emissions from magnesium
production and processing. However, global
efforts in recent years to eliminate the use of
SF6 in this application have reduced potential
emission growth.
Specifically, in 2003, the EPA's SF6 Emission
Reduction Partnership for the Magnesium
Industry formed a global industry commitment
through the International Magnesium
Association (representing approximately 80%
of magnesium production and processing
outside of China) to eliminate SF6 emissions
from operations by the end of 201072 The
U.S. partnership has ended, but facilities in
the United States that contain magnesium
production processes are required to annually
report emissions under subpart T of EPA's
Greenhouse Gas Reporting Program (40 CFR Part
98). In addition, regulatory efforts in Europe and
Japan and CDM projects in Brazil and Israel have
resulted in significantly reduced emissions.
Metals
Aluminum and Magnesium Production
Emissions from aluminum production decreased by 67% from 1990 through 2015, but
emissions are estimated to double from 2015 through 2030, primarily because of increased
production. Most of this growth is expected to occur in China, which is projected to produce
more than two-thirds of the world's PFC emissions from aluminum production by 2030.
Magnesium production emissions decreased significantly from 1990 through 2015, but
emissions are expected to increase because of growing global demand for magnesium in the
technology and automotive sectors.
Global Non-C02 Greenhouse Gas Emission Projections & Mitigation: 2015-2050 41

-------
Key Points
•	The metals source category emits 1% of the
global baseline emissions in 2030, making
this source a small emitter relative to the
others.
•	Aluminum production has the greatest
mitigation potential at 22 MtC02e—four
times the contribution from magnesium
production.
» The abatement potential at cost-effective
prices ($0/tC02e) is estimated to be 1% of
the metals baseline in 2030, rising to 18% at
prices below $20/tC02e.
Total Reduction Potential
Reducing emissions by 1 % compared with the 2020 baseline is eos-Uefrectlva
An additional 35S reduction is available using technologies with increasingly
higher costs.The emission reduction potential at increasing Costs rises to 38%
in 2030 and to48% in 2050
Baseline: 44 MtCO,e
Metal
Aluminum and Magnesium Productio

Abatement Measures
Abatement measures for metals come from
aluminum and magnesium production.
Abatement options considered in the
primary aluminum production industry
involve (1) a minor retrofit to upgrade the
process computer control systems and
(2) a major retrofit to the process computer
control systems coupled with the installation
of alumina point-feed systems. The analysis
does not include the installation of alumina
point-feed systems on its own because it
would be very unlikely that an aluminum
production facility would install alumina
point-feed systems without also installing
or upgrading process computer control
systems.
For the production and processing
of magnesium, replacing SF6 with an
alternative cover gas is the principal
abatement measure. The three options
for alternative cover gas in magnesium
production are S02, HFC-134a, and
Novec™ 612. Although toxicity, odor, and
corrosive properties are a concern of
using S02 as a cover gas, it can potentially
eliminate SF6 emissions entirely through
improved containment and pollution
control systems. HFC-134a, along with other
fluorinated gas, contains fewer associated
health, odor, and corrosive impacts than S02,
but it does have a GWP.The replacement of
SF6 with Novec™ 612 is under evaluation and
is currently being used in one remelt and
die-casting facility in the United States. Each
of the three cover gases has a reduction
efficiency between 95% and 100%.
61%
Baseline: 70 MtCO-e -
51%
2030
2050
Baseline: 117 MtC02e -
Reductions at
No Cost
Technically Feasible
at Increasing Costs
Residual
Emissions
Reduction Potential by Technology
In 2818, minor-retrofitting of process computer control systems is the leading
emission abatement measure in metals manufacturing, and 0,5 MtCOje-of
reductions ate achievable at prices below $O/tC02&: At prices greater than
S0/tCO|gi this measure-can mitigate 14 MtCOit,
Minor Retrofit (process computer control
systems only)
Major Retrofit (process computer control systems
+ alumina point feeding)
Alternative Cover Gas - Novec™ 612
Alternative Cover Gas - HFC-134a
Alternative Cover Gas - SO-
I
3	6	9	12	15
MtC02e
Reductions achievable at costs less than $0/tC02e
Reductions achievable at costs greater than $0/tC02e
Marginal Abatement Cost Curves, 2030
China has the highest basefineemissions for themetalS' source;category in 2030, followed by Russia, the United States, the United
Arab Emirates, and Canada. China contributes to-60% of global abatement potential, and the top S emitters combined contribute'
toS3%'Of global abatement potential.
Russia
$100


$60
-

$40
-

$20

$0

-$20
-
0 1 2 3 4 5 6 7
$60 ¦»
$40 -
$20 -
$0 -r
-$20 -
United Arab Emirates
11*1 Canada
$100
$80
$60
$40
$20
$oy
-$20
$100
$80
$60
$40
$20
$0
-$20
z
Abatement Potential
Metals production's abatement potential is estimated
to be approximately 28 MtC02e in 2030, or 39% of
the source's baseline emissions. Break-even prices
as low as $20/tCO2e can achieve nearly half of the
metals production's mitigation potential, and a price of
$5/tC02e can mitigate a quarter of metals emissions.
Reduction technologies used in the production of
aluminum offer the highest global abatement potential
in the metals source category. Minor and major retrofit
upgrades can potentially mitigate 21 MtC02e in 2030,
or 34% of aluminum's baseline emissions. In contrast,
using S02, HFC-134a, and Novec™ 612 as alternative
cover gases for magnesium production can mitigate
6 MtC02e, or 98% of magnesium's baseline emissions.
These alternative gases have low or zero GWP, which
leads to high reduction efficiency and potential
abatement.
United States
0 12 3 4 5 6 7
$100


pou
$60
-

$40
-

$20
-

$0
J,*-


-$20
-
0 1 2 3 4 5 6 7
Rest of World
$100 -
China, Russia, and the United States are the top
3 countries with the highest abatement potential in
2030. China has the potential to mitigate "17 MtC02e,
approximately a quarter of metal emissions. Russia
and the United States have the potential to mitigate
3 MtC02e and 2 MtC02e, respectively. Although these
nations have much lower potential than China, Russia,
and the United States can achieve higher abatement
potential at lower break-even prices. For example, 61 %
and 73%, respectively, of their national abatement
potential is possible at break-even prices less than
$20/tCO2e; whereas China can reach 40% of its
potential at the same prices.
42
Global Non-C02 Greenhouse Gas Emission Projections & Mitigation: 2015-2050 43

-------
Substitutes for Ozone-Depleting Substances
Source Background
HFCs are used as alternatives to several classes of ODSs that are
being phased out under the terms of the Montreal Protocol.
ODSs, which include chlorofluorocarbons (CFCs), halons, carbon
tetrachloride, methyl chloroform, and HCFCs, have been used in
a variety of industrial applications, including refrigeration and
air-conditioning equipment (ref/AC), aerosols, solvent cleaning,
fire extinguishing, foam production, and sterilization. HFCs are not
harmful to the stratospheric ozone layer, but they are powerful
GHGs. Calculations of HFC emissions from the use of substitutes for
ODSs are modeled by end use and country73 End uses are expected
to transition from ODSs to HFCs in response to the ODS phase-out.
HFCs are first consumed during manufacture and are mostly
emitted to the atmosphere over the lifetime of the equipment or
product from equipment leaks, servicing, and disposal. The EPA
used a modeling approach to determine emissions from the various
ODS end-use sectors that have transitioned to HFCs.
Historical Trends
Global ODS substitute emissions were estimated to rise from
0.01 MtC02e to 705 MtC02e between 1990 and 2015, driven by
growth primarily in ref/AC. The growth in emissions up to 2005
is primarily driven by the transition to HFCs under the Montreal
Protocol in OECD countries. This trend was accelerated from 2005
through 2015 as emissions of ODS substitutes from non-OECD
countries played an increasingly important role.
Projected Emissions &Top Emitting Countries
Key Points
2030 Emissions by Gas and Subsource
HFCs a re the p ri maty a'terna five to ODSs. PFCsan d
hydrofluoroethers (HFEs) are also used as alternatives
butt© a substantially lesser ©fejit than HFCs; therefore
emissions from thesegases atfi not estimated in this report.
The ref/AC subsource is the most significant contributor to
HFC;emissions in 2®30, comprising approximately 9Q% of
emissions.
Gas
Subsource
100
HFCs (100%)
Solvents (0.5%)
Fire Ext (1.5%)
Foams (2.8%)
Aerosols (4.7%)
Ref/AC (90.5%)
Emissions (MtC02e)
From 201S through 2Q30, HFC
emissions from use m substitutes for
ops ate projected to double.
2030 Emissions from Top 5 Emitting Countries
Rest of World: 669 MtC02e

1,786

%
65
114
Top 5 Emitters
China
United States
Saudi Arabia
Thailand
South Korea
Projected Trends
1990 2000 2015 2 0 3 0 2050
Emissions (MtC02e)
Through 2030, emissions and consumption of HFCs are
expected to grow in both developed and developing
countries but will grow much more quickly in developing
countries. In contrast to developing countries where
emission increases are driven by growth in the amount
of equipment used, emission increases in developed
countries are driven primarily by the aging and
replacement of existing ODS equipment. Reduction in
consumption through enhanced recovery and reuse,
transitions to more efficient equipment, and the use of
low- or no-GWP alternatives could avert these projected
emission increases.
For this analysis, the BAU scenario does not incorporate
measures to reduce or eliminate the future emissions
of these gases, other than those regulated by law or
otherwise largely practiced in the current market,
including In the European Union, Australia, and Japan.
These developed country-level agreements control HFC
consumption and have led to reduced emission growth.
Reduction schedules from these policies were applied
across all sectors and, for the European Union, across all
countries.
Although the BAU forecast incorporates some transitions
that are occurring currently (e.g., HFO-1234yf replacing
HFC-134a in light duty vehicle air-conditioning in some
OECD countries),74 the model does not project all
future market transitions, including those anticipated
by industry. There is significant uncertainty as to what
chemicals will replace HFCs in applications using
ODS substitutes, particularly in developing countries.
Although existing policies in the European Union,
Australia, and japan were modeled as mentioned above,
future policies that could affect consumption of HFCs,
and therefore emissions, were not modeled here.75
For instance, over 70 countries have ratified the Kigali
Amendment to the Montreal Protocol, which calls for
a phase-down in HFC consumption. The BAU forecasts
for those countries do not attempt to explicitly model
any specific actions taken to comply with the Kigali
Amendment because the actions that would be taken
are unknown at this time and would be decided at the
national level.
Global HFC emissions are expected to increase
significantly through 2030 because of the continued
transition to ODS substitutes.
Growth of ref/AC in developing countries is the
primary driver of the significant increase in HFC
emissions through 2030, particularly in China, Saudi
Arabia, and Thailand. Growing populations, economic
development, and a lack of HFC alternatives in these
countries are driving the increasing demand for HFC
use in ref/AC.
44
Global Non-C02 Greenhouse Gas Emission Projections & Mitigation: 2015-2050 45

-------
Key Points
• The global abatement potential for the
ODS substitutes source category reaches
549 MtC02e—roughly 38% of baseline
emissions—in 2030.
•	HFC emissions from ref/AC manufacturing
make up the greatest mitigation potential
from ODS substitute sources, reaching
515 MtC02e, or 35% of baseline emissions in
2030.
•	Aerosols have the second highest abatement
potential, reaching 33 MtC02e.
•	Fire suppressants, solvents use, and foams
represent just 0.6% of mitigation potential.
Total Reduction Potential
Reducing emissions by 1 % compared with the lQ20 baseline fe
An additional 5fo reduction is available.using technologies with increasingly
higher costs.Theeost-effectlve reduction potential rises to Wo in 203Q and to
36% in 2650.
Abatement Measures
The ODS substitutes source category contains
five sources and their subsequent abatement
measures: aerosols; solvents; fire protection;
foams manufacturing, use, and disposal; and ref/
AC.
Aerosol abatement measures fall into
two categories: consumer products and
pharmaceutical products. Abatement measures
for consumer aerosols include transitioning to a
replacement propellant and converting to a not-
in-kind alternative such as a finger pump. For
pharmaceutical products, this analysis considers
the use of dry powder inhalers.
Measures to abate emissions from the use of
solvents include precision or electronic cleaning
on retrofitted and nonretrofitted equipment.
The nonretrofitted options account for greater
emissions coming from developing countries
performing the same cleaning processes as
developed nations but with fewer emission
control technologies.
For fire protection, this analysis considers
options that use zero-GWP or low-GWP
extinguishing agents. The options are applied
to technologies that protect against Class A
surface fire hazards or Class B fuel hazards in
large (>3,000 m3) marine applications.
The abatement measures considered for foam
manufacturing fall into the categories of
replacing HFCs with low-GWP blowing agents
or properly recovering and disposing of foam
contained in equipment.
The refrigeration and air-conditioning
discussion considers 20 new technologies
and three improved technician practices that
are applicable in either a residential, retail, or
transportation setting.
m
94%
Baseline: 936 MtCO,e.
62%
Baseline: 1,452 MtCO.e ¦
20%
2020
2030
2050
Baseline: 1,786 MtC02e
Reductions at
No Cost
Technically Feasible
at Increasing Costs
Residual
Emissions
Reduction Potential by Technology
In 2030, the top12 abatement measures-come from the refrigeration and air-
conditioning sUbsourcft-Refrigerant recovery at disposal for Existing: refrigeration/
AC equipment is the: leading measure With 242 MtCO?e of potential abatement
at prices above" $0/tC£lje. Refrigerant recovery at servicing for existing: small
equipment is thesecond leading measure with 88 MtCOjeof potential
abatement at prices abow SQ/tCQie.
Refrigerant Recovery at Disposal for Existing ¦
Refrigeration/AC Equipment
Refrigerant Recovery at Servicing for Existing Small
Equipment B
Leak Repair for Existing Large Equipment
HF0~1234yf in motor vehicle air-conditioners |
NH3 and C02 in cold storage and industrial process
refrigeration (I PR)
Residential Unitary AC - R-452B and MCHE
Large Retail Food ~ C02 Transcritical
Substitute NIK for HFC- 152a
Dry Powder Inhalers
Substitute NIK for HFC-134a
Substitute HC for HFC-134a
Medium Retail Food - C02
Other Measures
0
50
200
100 150
MtC02e
Reductions achievable at costs less than $0/tC02e
Reductions achievable at costs greater than $0/tC02e
250
46
[arices
I
Marginal Abatement Cost Curves, 2030
Taken together, the top 5 countries in terms of baseline emissions represent 55% of global abatement potential in the source
category in 2030. China has the highest emissions and can potentially abate 106 MtC02e. The United States has the second
largest potential abatement in 2030, reaching 81 MtC02e.
$100
Thailand
United States
50	100
South Korea
Saudi Arabia
$100 i—
$60
$40
$20
-4 $0
-$20
250 0
r
o
©
Rest of World
$100
$100 r
$100
$60
$40
$20
$0
-$20
$60 -
$40 -
$20
$0
-$20
V-
$60 -
$40 -
$20 -
$0
-$20 -
-$40 ¦
Abatement Potential
Abatement of HFC emissions from this collection of
sources is challenging given the available technology.
This analysis estimates that available abatement
technologies can only abate approximately 1 % of
emissions from fire protection and foam-related
emissions. Abatement potential in emissions from
solvent use rises to 9%. Abatement potential in
emissions from aerosols is 48% of aerosol-related
emissions because of readily available ways to remove
aerosols from consumer products.
Emissions from ref/AC contribute to 90% of baseline
emissions from the ODS substitutes category and
are also the largest source of potential abatement.
Abatement measures targeting ref/AC emissions have
the potential to abate 515 MtC02e of emissions, which
represents 39% of baseline ref/AC emissions.
Even though most individual abatement technologies in
this category have relatively low expected effectiveness,
as a whole substantial emission reductions are available
at cost-effective prices. Across all ODS substitute sources,
25% of abatement potential is available at prices below
$0/tCO2e. By contrast, out of the total non-C02 emission
abatement potential across all sources globally, only 21 %
is available at prices below $0/tCO2e.
Just 3 of the 42 technologies considered across all ODS
sources provide 72% of abatement potential. The largest
amount of potential abatement can be achieved through
recovering refrigerant at disposal for existing ref/AC
equipment (242 MtC02e) at prices above $0/tCO2e;
recovering refrigerant at servicing for existing small
equipment unlocks an additional 88 MtC02e at costs
above $0/tCO2e, Finally, 65 MtC02e is achievable below
prices of $0/tCO2e by repairing leaks in existing large
equipment.
In 2030, China, the United States, and Saudi Arabia have
the highest emissions from the ODS substitutes source
category, making them the largest potential sources
of abatement as well. China represents 106 MtC02e of
abatement potential, followed by 81 MtC02e from the
United States. The top 3 emitters combined account for
43% of the global abatement potential.
Global Non-C02 Greenhouse Gas Emission Projections & Mitigation: 2015-2050

-------
HCFC-22 Production
Source Background
Trifluoromethane (HFC-23) is generated and emitted as a by-
product during the production of chlorodifluoromethane
(HCFC-22). HCFC-22 is used primarily as a feedstock for
production of synthetic polymers and in emissive applications,
primarily ref/AC. Because HCFC-22 depletes stratospheric ozone,
its production for nonfeedstock uses is scheduled to be phased
out under the Montreal Protocol. However, HCFC-22 production
for feedstock uses is permitted to continue indefinitely. HFC-23
emissions from HCFC-22 production can be avoided through
thermal destruction and reduced through process optimization.
Historical Trends
Global HFC-23 emissions from HCFC-22 production are estimated
to have increased by 12% between 1990 and 2015, driven by
high growth in global HCFC-22 production during that period.
Between 1990 and 2005, the majority of emissions shifted from
OECD countries to non-OECD Asia. This shift is due to both
a combination of increased use of emission controls and the
phase-down of HCFC-22 under the Montreal Protocol in OECD
countries, as well as increased HCFC-22 production in China and
India.
2030 Emissions by Region and End Use
In 203Q:, HCFC-22 production for emissive (le, nonfeedstock)
purposes is expected to be phased out in developing
eountri# because of the requirements of the Montreal
Protocol. HCFC-22 production for feMstock Use is anticipated
to grow at par year globally, BeJbts:the phaseout of
production of HCFC-22 for emissive purposes under the
Montreal Protocol, feedstock production made Up 805$ of
HCFC-22 production in Japan, 5B% in otherCJECD'esuntries,
1351 in China, and 7% in all other non-OECD countries From
2030 onward, HCFC-22 production is solely for feedstock use,.
100
20
42
58
80
83
93
Japan
Other
OECD
Nonfeedstock
China
Other
Non-OECD
Feedstock
Projected Emissions &Top Emitting Countries
Emissions (MtC02e)
From 20] S through 2Q30:, HFC-23
emissions from HCFC-22 production are
projected to increase by 109&
443
1990 2000 201 5 2 0 3 0 2050
Emissions (MtC02e)
2030 Emissions from Top 5 Emitting Countries
Rest of World: 3 MtC02e
Top 5 Emitters
"9
f
China
Russia
Argentina
South Korea
Venezuela
48
Key Points
•	Global HFC-23 emissions from HCFC-22 production
are expected to decrease between 2015 and 2020 but
then increase through 2030 because of the continued
demand for HCFC-22 for feedstock uses.
•	Nonfeedstock HCFC-22 production will be phased out
in developed countries between 2015 and 2020 and
in developing countries between 2015 and 2030.
•	Developing countries, particularly China and India,
are driving the significant increase in HFC-23
emissions through 2030.
•Hmi.
Projected Trends
Global HFC-23 emissions from HCFC-22 production are
expected to decrease between 2015 and 2020, increase
slightly through 2030, and then increase significantly
through 2050. Key factors influencing the trend in the
global BAU emission scenario from 2015 through 2030
include a phase-out of nonfeedstock HCFC-22 production
in developed countries between 2015 and 2020, which
results in a temporary reduction in HFC-23 emissions over
that period, and a phase-out of nonfeedstock HCFC-22
production in developing countries between 2015 and
2030. HCFC-22 production for feedstock use is expected
to grow at approximately 5% per year.
HFC-23 emissions are also expected to begin Increasing
after 2020 through 2030 and beyond because some
facilities with CDM projects (mitigation projects funded
by developed countries under the Kyoto Protocol) are
no longer expected to be destroying HFC-23 emissions.
Destruction of HFC-23 from HCFC-22 production
was previously a major source of credits in the CDM
program. Some facilities with CDM projects are no longer
destroying HFC-23 emissions; however, China recently
constructed new destruction facilities on 15 HCFC-22
production lines, although this is not explicitly modeled
in the BAU76
Future emission and abatement levels are particularly
uncertain. Future policies (e.g., under the Montreal
Protocol) are not included in the BAU emission
projections and could affect total production of HCFC-22
and therefore emissions of HFC-23. For example, the
Kigali Amendment to the Montreal Protocol mandates
all HCFC-22 producing facilities to collect and destroy
HFC-23 by-product beginning in 2020 to the extent
practicable. Since most, if not all, HCFC-22 production
plants have access to existing destruction facilities, they
could restart the equipment that was used to previously
destroy HFC-23 if the equipment is not currently in use.
Changing emission rates as a result of implementing
abatement technology, process optimization, or other
means may also have a significant impact on emissions.
These factors taken together suggest that a significant
portion of projected emissions can be avoided.
Global Non-C02 Greenhouse Gas Emission Projections & Mitigation: 2015-2050 49

-------
Key Points
•	The global abatement potential for the
HCFC-22 production source category is 147
MtC02e (88% of baseline emissions) in 2030.
•	China, Argentina, and South Korea represent
96% of the maximum abatement potential
in 2030,
•	Thermal oxidation is the only abatement
option considered for the HCFC-22
production source category.
•	Abating HCFC-22 emissions is relatively low
cost: all potential abatement is achievable at
costs below S5/tC02e.
Abatement Measures
For the HCFC-22 production source category,
this analysis assumed that facilities in most
developed countries have already adopted
abatement measures. As a result, abatement
potential is limited to developing countries.
This analysis examined only one abatement
measure—thermal oxidation.This measure
destroys halogenated organic compounds
by oxidizing HFC-23 to hydrogen fluoride,
water, and C02. The fraction of production
time that the device is running determines
the actual reduction potential. The unit may
require downtime because destruction requires
high temperatures and hydrogen fluoride
is highly corrosive.This analysis assumed a
reduction efficiency of 95%, indicating that
this technology can abate 95% of emissions
when used. Furthermore, the HCFC-22
production source category has a 95% technical
effectiveness in this analysis, meaning that this
measure has the potential to reduce 95% of
baseline emissions at the national level.
Thermal oxidation equipment has a iifetime of
approximately 20 years, making it a long-term
capital investment. Installing thermal oxidation
in a new plant is cheaper than in a preexisting
plant. The estimated capital cost to upgrade
an existing plant is approximately $5.2 million,
but only $4 million to build this technology
into a new plant while the plant is under
construction. Another option is to restart a
preexisting incinerator, which costs $400,000, on
average. Furthermore, the annual operating and
maintenance cost is approximately $200,000.
Thermal oxidation does not provide any revenue
or cost savings.
Total Reduction Potential
There are no emission reductions available in HCFC-22 production at prices
below $Q/tCp3fi However, in 20®, an 82® reduction is achievable when using
technologfesWith increasingly higher Costs,- and this percentage rises to 88%: in
2030 find XQ95% in 205ft
Baseline: 114 MtC02e	^
12%
Baseline: 167 MtCO e
Baseline: 443 MtCO,e
5%
2020
2030
2050
Reductions at
No Cost
Technically Feasible
at Increasing Costs
Residual
Emissions
Reduction Potential by Technology
Thermal oxidation was theorily abatement measure1 modeled for the HCFC-221:
production source category.The technology has the potential, tea bate 14?
MtCOjS in 23301 All the reductions are achievable St ^ostsfteater than SQ/tCOaf,'
Thermal Oxidation
30
120
150
MtC0,e
Reductions achievable at costs less than $0/tC02e
Reductions achievable at costs greater than $0/tC02e
Marginal Abatement Cost Curves, 2030
Taken together, the top 5 countries in terms of baseline emissions represent 98% of all potential global abatement in the source
category in 2030. China is the highest emitting country but also contributes to 91 % of global abatement potential for the source
category, or 134 MtC02e, in 2030.The MAC curves in this source category look like straight lines because only one abatement
technology was modeled, leading most abatement to fall at very similar price points.
China
Russia
$100 r
$80
$60
$40
$20
$0
-$20
South Korea
$100
$80
$60
$40
$20
$0
-$20
$100
$80
$60
$40
$20
$0
-$20
$100
$80
$60
$40
$20
$0
-$20
Venezuela
Abatement Potential
The global abatement potential for the HCFC-22
production source category is estimated to rise over
time. In 2020, the maximum abatement potential is
93 MtC02e, or 82% of baseline emissions. However,
abatement potential is expected to increase to
147 MtC02e and 420 MtC02e in 2030 and 2050,
respectively, or approximately 88% and 95% of baseline
emissions. Maximum abatement potential can be
achieved at little or no cost;ali of the potential can be
reached with break-even prices between $0/tCO2e and
$1/tC02e.
China has the leading abatement potential from
the HCFC-22 production source category across the
modeled time horizon. In 2030, China's abatement
potential is 130 MtC02e higher than the country with
the second highest potential, Argentina. Furthermore,
Argentina
150 0
- $100
580
$60
540
520
—* so
-520 L
150 0
5100

30	60	90	120	150
Rest of World
China experiences growth in its mitigation potential
over time. In 2015, China can abate 43 MtC02e, or
38% of baseline emissions. However, by 2030, the
country is estimated to mitigate 134 MtC02e, which is
the equivalent of 80% of the baseline emissions and
85% of the source category's total annual abatement
potential.
In 2030, the other leading countries with the most
abatement potential are Argentina, South Korea,
Russia, and Venezuela. These countries can abate 7%
of the baseline emissions and contribute to 7% of the
potential mitigation from the HCFC-22 production
source category. Argentina and Venezuela can
potentially abate 4 MtC02e and 1 MtC02e, while Russia
and South Korea can each potentially reach 3 MtC02e
in abatement.
50
Global Non-C02 Greenhouse Gas Emission Projections & Mitigation: 2015-2050 51

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Introduction
The agriculture sector is the largest contributing sector
to global emissions of non-C02 GHGs, accounting for
48% of emissions in 2015. This section presents global
agriculture-sector CH4 and N20 historical and projected
emissions and the mitigation potential from the
following source categories:
•	Livestock (CH4, N20)
•	Croplands (CH4, N20)
•	Rice cultivation (CH4, N20)
Projections and MAC curves were estimated for all source
categories; however, within croplands, the mitigation
analysis was restricted to major crops that represent 61 %
of global croplands. Also, rice is considered separately.
Between 2015 and 2030, global agriculture-sector
emissions are projected to increase 10%, reaching
6,339 MtC02e in 2030. Agricultural soil emissions and
enteric fermentation emissions are projected to increase
the largest amount, by 14% and 12% between 2015
and 2030, respectively. Emissions in the agriculture
sector are projected to increase because of increased
fertilizer consumption, crop production, and livestock
populations, which are driven by demand for animal
products. The growth rate in the demand for animal
products is expected to increase significantly in
developing economies but is expected to be slower or
negative in non-Annex I economies.
Historical and Projected Emissions from the
Agriculture Sector
Riil

8,000

7,000
"aT
6,000
O

u
5,000
1


4,000
c
q


3,000
S
LLI
2,000

1,000
1990 2000 2015 2030 2050
Other Agriculture
Rice
Croplands
Livestock
Mitigation potential from the agriculture sector is
estimated to be approximately 593 MtC02e in 2030. This
mitigation potential is 9%, 3%, and 36% of livestock,
croplands, and rice cultivation emissions, respectively;
9% of overall agriculture-sector emissions; and 16% of
total global non-C02 mitigation potential in that year.
Emission Reduction Potential, 2030
91
Baseline: 6,339 MtC02e
Reductions at No Cost
Technically Feasible at Increasing Costs
Residual Emissions
Global Non-C02 Greenhouse Gas Emission Projections & Mitigation: 2015-2050 53

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Livestock
Enteric Fermentation and Manure Management
Source Background
Emissions from livestock include enteric fermentation and manure
management. Enteric fermentation is a normal mammalian
digestive process, where gut microbes produce CH4 that the
animal exhales. Livestock manure management produces CH4
emissions during the anaerobic decomposition of manure and
N20 emissions during the nitrification and denitrification of the
organic nitrogen content in livestock manure and urine.
Historical Trends
Between 1990 and 2015, combined CH4 and N20 emissions from
livestock increased 16%. Roughly 80% of livestock emissions are
CH4 emissions from enteric fermentation. Between 1990 and
2015, global CH4 emissions from enteric fermentation and manure
management increased by 13% and 33%, respectively. The total
cattle population increased by 31%, and livestock production
systems shifted from grazing and mixed systems toward intensive
specialized livestock production systems that typically have
manure management systems with high CH4 emissions.77^8
The primary driver for the increase in emissions from both
livestock sources was the increase in livestock populations, most
of which occurred in Asia, Africa, and the Middle East. In contrast,
emissions in developed economies experienced more stagnant
and even negative growth.
2030 Emissions by Gas and Subsource
The last majority of emissions from livestock sbs€H4 emissions
from enteric Fermentation.
Gas
Subsource
100
N2G (9%)
CH4 (91%)
Manure (19%)
Enteric (81%)
Projected Emissions &Top Emitting Countries
Emissions (MtC02e)
From 2015 through 2036,CFt4 and NjQ
emissions From livestock are projected
t©Increase by approximately TQ%.
2030 Emissions from Top 5 Emitting Countries
Rest of World: 1,843 MtC02e
3 *")7
3,583


Top 5 Emitters
China
India
Brazil
United States
Pakistan
1990 2000 2 0 1 5 2 0 3 0 2050
Emissions (MtC02e)
54
economies
Projected Trends
From 2015 through 2030, emissions from enteric
fermentation and manure management are projected
to increase 12% and 5%, respectively. These projections
assume increases in livestock populations, including 12%
for dairy cows and cattle and 10% for poultry. However,
these projections do not account for possible changes
in emissions per head of livestock due to changes in
management practices, animal feed, or genetics, all
of which can increase or decrease emission estimates.
For example, conversion to intensive specialized
livestock production systems typically results in manure
management systems with higher CH4 emissions.Thus,
these emission estimates may either over- or understate
future emissions. The individual country-reported data
may account for some of these practices.
Most enteric fermentation emissions come from dairy
cows, cattle, and buffalo. World projections through 2025
show increases in meat product consumption, production,
and trade, most of which is projected to occur in
developing countries.^ In China, demand and production
of both meat and milk have been growing rapidly, and
China is expected to be one of the largest sources of
emissions from enteric fermentation through 2030. Total
enteric emissions are projected to grow at a slower pace
than the corresponding cattle population increase.
In contrast, in developed countries, emissions from
enteric fermentation are expected to decline through
2030. Cattle inventories are projected to decrease in
the European Union and Russia because of increases
in cattle productivity and decreases in animal product
consumption.so
Manure management emissions are also projected to
increase because of increasing populations of dairy
cows, cattle, buffalo, and poultry, most of which are
projected to occur in developing countries. Poultry
production is projected to increase approximately 14%
over the next decade, making it the primary driver of
growth in global meat productions This increase will
drive increases in N20 emissions because of the relatively
high nitrogen content of poultry waste and the manure
management systems used. The increase in dairy cow
and cattle populations over the next decade is projected
to occur mostly in developing countries, which have
lower per-animal manure management emission rates
than developed countries. However, as dairy- and cattle-
producing countries transform to larger livestock and
manure management systems, the trend will likely be
toward increasing CH4 emissions.
Global Non-C02 Greenhouse Gas Emission Projections & Mitigation: 2015-2050 55

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Key Points
•	Livestock accounts for 24% of baseline non-
C02 emissions in 2030.
•	The largest low-cost reductions in emissions
result from implementing strategies
to improve feed conversion efficiency,
incorporate feed supplements, and increase
the use of small-scale anaerobic digesters.
•	The abatement potential from livestock
is 298 MtC02e in 2030, or 9% of baseline
emissions.
Abatement Measures
The analysis considers six enteric fermentation
CH4 abatement measures: improved feed
conversion efficiency, antibiotics, bovine
somatotropin (bST), propionate precursors,
antimethanogen vaccines, and intensive
grazing. Many of the currently available
enteric fermentation abatement options work
indirectly by increasing animal growth rates
and reducing time to finish (or increasing milk
production for dairy cows). These abatement
measures achieve emission reductions because
increased productivity means fewer animals are
required to produce the same amount of meat
or milk. Furthermore, several of the abatement
measures are inexpensive to implement and
are cost-effective at reducing emissions. For
example, the average annual operation and
maintenance cost for antibiotics ranges from
$4 to $9 per head. Likewise, intensive grazing
can save farmers up to $180 annually while
reducing emissions by 9 MtC02e at break-even
prices below $0/tCO2e.
In the case of manure management (CH4
and N20), this analysis considers four large-
scale abatement measures that are applied in
developed regions: complete-mix, plug-flow,
fixed-film digesters, and covered lagoons.
Small-scale dome digesters are also included
to provide a lower cost abatement measure
and exhibit a measure used in developing
regions. These digesters mitigate emissions
from manure but also generate revenue for
farms by generating heat and electricity from
captured CH4 gases. For example, implementing
a complete-mix digester with an engine on
a dairy cattle farm can create $65 in energy
revenue per head.
Total Reduction Potential
Reduci ng emissions by 2% compared with the baseline in 2828 is cost-
effective. With increasingly higher cQSts,an additional J% reduction is possible.
The c;osWffectl¥& reduction potential remains at2% in 2030'and declines to
]«in 2C5SO'.
2%
91%
Baseline: 3,137 MtCQ e
2%
Baseline: 3,327 MtCO e
1%
92%
Baseline: 3,583 [vltCO.e
Reductions at
No Cost
Technically Feasible
at Increasing Costs
2020
2030
2050
Residual
Emissions
Reduction Potential by Technology
In 203(3, anti metha nogens offers the most overall potential abatement, followed
by propionate precursors. Cost-effectiVe abatement fromantimethanogens^
propionate pfficursorSi-and intensive grazing can reduce emissions by 70 MtCOife
Marginal Abatement Cost Curves, 2030
China hgs the highest baselineemissions from livestock in 2WQ, followed by India, Brazil, theUnlted State®, and Pakistan. In total,
the' top Remitters represent 45# of baseline amissions. With the exception of the UnitesiStatesand India, abatement potential is
less than 9i>of the national baseline-emissions for the top emitters.
$100
India
Brazil
$100 -
Pakistan
20 40 60
Rest of World
$1oo -
United States
Antimethanogen
Propionate Precursors
Improved Feed Conversion
Large- scale Complete Mix Digester Without Engine
Large-scale Covered Lagoon With Engine
Large-scale Complete-mix Digester With Engine
Large-scale Covered Lagoon Without Engine
Intensive Grazing
Antibiotics
Large-scale Fixed-film Digester With Engine
Large-scale Fixed-film Digester Without Engine
Other Measures
0 10 20 30 10 50 60 70 80
MtC02e
^¦1 Reductions achievable at costs less than $0/tC02e
Reductions achievable at costs greater than $0/tC02e
Abatement Potential
Technologically feasible global abatement potential
from livestock is estimated at 298 MtCQ2e in 2030, a
9% reduction compared with the baseline. The total
abatement potential is expected to remain roughly
the same as a percentage of baseline emissions
through 2050. In 2030,26% of emission reductions are
achievable at break-even prices below $0.
Using antimethanogen has the highest global
abatement potential in 2030, reaching 73 MtC02e,
with propionate precursors as a close second, abating
47 MtC02e. Large-scale complete-mix digesters,
covered lagoons with and without engines, and fixed-
film digesters with engines all provide the third highest
abatement potential at 19 MtC02e each. Only five of
the measures have abatement potential at no cost:
antimethanogen, propionate precursors, intensive
grazing, improved feed conversion, and bST. Mitigation
potential at no cost accounts for 26% of total livestock
potential. Propionate precursors can reach 59% of
abatement potential at no cost. Likewise, 46% of the
abatement potential for antimethanogen is also cost-
effective.
In 2030, China, India, and Brazil have the highest
emissions but are also large sources of potential
abatement. The fourth highest emitter is the United
States, and it offers the highest abatement potential.
China, India, and Brazil can potentially abate
40 MtC02e, 19 MtC02e and 15 MtC02e, respectively,
and the United States' potential reaches 78 MtC02e.
Together the top 3 emitters contribute to a quarter of
livestock's abatement potential in 2030. These three
countries can reach between 26% and 39% of their
individual abatement potential at break-even prices
below $0/tCO2e, whereas only 1% of the United States'
potential can be achieved at break-even prices below
$0/tCO2e. Using antimethanogens is the measure that
offers either the first or second highest abatement
potential for each of these countries, which falls in line
with the global trend.
Enteric Fermentation and Manure Management
56
Global Non-C02 Greenhouse Gas Emission Projections & Mitigation: 2015-2050 57

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Croplands
Emissions from Agricultural Soil Management
Source Background
A number of land management activities add nitrogen to soils,
thus increasing the amount of N20 emitted. Examples of land
management activities that directly add nitrogen to soils include:
•	Various cropping practices, such as (1) application of fertilizers;
(2)	incorporation of crop residues into the soil, including those
from nitrogen-fixing crops (e.g., beans, pulses, and alfalfa); and
(3)	cultivation of high organic content soils (histosols); and
•	Livestock waste management, including (1) spreading of
livestock wastes on cropland and pasture and (2) directly
depositing wastes by grazing livestock.
Indirect additions of nitrogen occur through volatilization and
atmospheric deposition of ammonia and oxides of nitrogen
that originate from (1) the application of fertilizers and livestock
wastes onto agricultural land and (2) surface runoff and leaching
of nitrogen from these same sources.
Historical Trends
Between 1990 and 2015, N20 emissions from agricultural
soil management increased by 27% because of increased
global fertilizer consumption, crop production, and livestock
populations. Over this period, total synthetic fertilizer usage
in crop production increased by 33%, total crop production
increased by 39%, and nitrogen excretion from livestock
increased by 19%.
2030 Emissions by Gas and Subsource
N2Gemissions from agricultural soils include emissions from
fertilizer consumption, crop residues incorporated into soils, and
manure left on pastUffc Manure left on pasture is the primary
seliree-of N_0 emissions from agricultural soils, accounting for
S3® of emissions in 283Q, The share of emissions from fertilizer
consumption, crop residues, and manuralefton pasture ts based
on calculated estimates.
Gas	Subsource
100
N20 (100%)	Crop Residues (8%)
Fertilizer (39%)
Manure on Soils (53%)
Projected Emissions &Top Emitting Countries
Emissions (MtC02e)
From 201S through 2030, NjO
emissions from agricultural'.tolls-are
projected to increase ,by
2,451
2,206
1990 2000 2 0 1 5 2 0 3 0 2050
Emissions (MtC02e)
2030 Emissions from Top 5 Emitting Countries
Rest of World: 1,129 MtC02e

Top 5 Emitters
china
United States
Brazil
India
Argentina
58
Key Points
• N20 emissions from agricultural soils are projected to
account for 16% of total non-C02 emissions by 2030,
From 1990 through 2015, N20 emissions from agricultural
soils grew roughly in proportion to crop production and
fertilizer consumption, and crop production increased in
proportion to fertilizer consumption (+39% versus +33%,
respectively).
Under the BAU scenario, emissions are estimated to
increase by 14% from 2015 through 2030, in line with the
historical trend in emissions.
Projected Trends
From 2015 through 2030, N20 emissions from
agricultural soils are projected to increase by 14%.
This projection assumes continued increases in
crop production, crop area harvested, and fertilizer
consumption to support projected increases in global
population.^ Over the projection period, emissions are
expected to increase in all regions. The primary factor
for the increase in emissions from 2015 through 2030
is increased synthetic fertilizer consumption to meet
growing agricultural demand in Africa, the Middle East,
Central and South America, and non-OECD Asia.
Emission increases in Africa, the Middle East, and non-
OECD Asia are somewhat offset by declining emissions
or slower growth in OECD countries (such as Germany
and France) because of decreasing livestock populations,
economic and environmental agricultural policies, and
improved farming practices. Because of the complexities
of agricultural product markets and the influences of
disruptions in the industry (such as food safety issues),
many of these factors are hard to predict.
In Africa, non-OECD Asia, and Central and South America,
the anticipated growth from 2015 through 2030 in
agricultural soils emissions has several causes. Increases
in population and per capita income will increase the
demand for agricultural products such as cereal grains,
milk, oilseed products, and meat. In addition, livestock
operations are expected to become more advanced in
these areas, thereby increasing demand for high-quality
feed crops (e.g., corn based). Whiie some of this demand
will be addressed in the short term through increases
in imports, long-term demand is expected to be met
domestically as the agricultural production industry
expands.
Emissions from agricultural soils are also influenced by
the livestock industry, which also drives the demand
for crop production for feed and ieads to an increase in
the amount of fertilizer and additional nitrogen inputs
required to produce feed. In addition, the increased
commercialization of the livestock industry is expected
to increase livestock production capacity, which leads to
increased emissions from livestock manure, the largest
estimated component of N20 emissions for this source
category when deposited directly on agricultural soils.
Global Non-C02 Greenhouse Gas Emission Projections & Mitigation: 2015-2050 59

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Key Points
• Global emission reduction potential from
croplands is 74 MtC02e in 2030, or 3% of
baseline emissions.
•	This analysis considers six abatement options
to reduce soil management emissions.
•	The implementation of no-till cultivation and
reduced fertilizer applications represents
80% of reductions.
• At break-even prices below $0/tC02e,
cropland abatement measures can mitigate
45 MtC02e (2% of this source's baseline
emissions).
Total Reduction Potential
Potential abatement for nomCGs emissions from croplands is small in
percentage terms, standing aKSi of ba?eline©mlssic>ns in 2030, At a baseline
of2,206 MtCOjf in 2030, abatement potential amounts to 14 MtCGi#,, Roughly
two-thirds of abatement potential is feasible at no net cost..
97%
Abatement Measures
This analysis considers six abatement measures
for croplands. For the first measure, no-till
management, the analysis does not consider
any cultivation or field preparation except for
seeding. The second analyzed measure is split
nitrogen fertilization application, which applies
fertilizer 3 times in equal amounts instead
of only once on the initial planting day. The
third measure is the application of nitrification
inhibitors simultaneously with the annual
nitrogen fertilizer application, which reduces
nitrification by 50% for 8 weeks. The fourth
and fifth abatement measures considered the
impacts of either increasing or decreasing
nitrogen fertilization by 20% above or below
the baseline. The final measure, "100% residue
incorporation, assumes that all residue remains
after harvest and allows for evaluating how
reducing residue removal could affect soil
organic carbon stocks.
Each of the abatement measures can lower
or raise farm costs, depending on changes
in farm labor and equipment usage. Use of
100% residue incorporation has no associated
costs, and reducing fertilization is expected
to lower costs because less fertilizer will be
purchased. In contrast, increasing fertilization
and split nitrogen fertilization could raise
costs because more fertilizer is used and
labor increases. Furthermore, using no-till
management could lower labor costs because
less direct labor is needed due to the reduction
in field preparation. However, purchasing
equipment for direct planting is a potential
increase in capital costs associated with no-till
management.
Baseline: 2,025 WltC02e .
97%
Baseline: 2,206 MtCO,e -
97%
2020
2030
2050
Baseline: 2,451 MtCO,e -
Reductions at
No Cost
Technically Feasible
at Increasing Costs
Residual
Emissions
Reduction Potential by Technology
A 2096 reduction in fertilizer use represents the largest shareof abatement
potential from thjssourceglobalJy, responsible'for461; of mitigation in croplands,
Across all abatement measures, M196 ofabatement potential is available at nO'COst.
20% Reduced Fertilizer
No Till
Nitrification Inhibitor Fertilizer
Split Fertilization
I
100% Residue Incorporation
20% Increased Fertilizer
10
20
50
30 40
MtC02e
Reductions achievable at costs less than $0/tC02e
Reductions achievable at costs greater than $0/tC02e
70
Croplands
Mitigation from Agricultural Soil Management
Marginal Abatement Cost Curves, 2030
China and the United States together represent 3491 of cropland emisslons.Taken together, the top SCountfieS in terms of
baseline emissions represent 52% of a|| potential global abatement from this source in 20®
United States
Rest of World
Argentina
Abatement Potential
Globally, croplands are responsible for 2,206 MtC02e
of emissions in 2030. Of these emissions, technology
is available to mitigate 3%, or 74 MtC02e. In 2030,61 %
of potential mitigation is available at break-even prices
below $0/tCO2e. Additional reductions are possible
with the inclusion of more costly abatement measures.
For example, mitigation potential increases to
53 MtC02e by including abatement measures with an
implementation cost less than or equal to $50/tCO2e.
A 20% reduction in fertilizer use represents the largest
share ofabatement potential from this source globally,
responsible for 46% of mitigation in croplands.
No-till practices are responsible for 34% of global
GHG abatement potential, and nitrification inhibitors
provide an additional 15% of abatement potential.
The majority ofabatement potential for both reduced
fertilization and no-till is available at no cost, 63% and
81%, respectively.
In 2030, China, the United States, and India are
responsible for the largest abatement potential in
croplands, 19%, 16%, and 9%, respectively. In China,
94% ofabatement potential, or 14 MtC02e, is achievable
at no cost. In the United States and India, 75% and 70%
ofabatement, respectively, is cost-effective with no
additional incentives. Only 0.05 MtC02e of abatement
potential in China is achievable at costs between $0
and $20/tCO2e. Similarly, in the United States, almost no
additional abatement is achievable at prices between
$0/tCO2e and $20/tCO2e. Similar to global trends,
reducing fertilization by 20% is the leading abatement
measure for China, the United States, and india,
contributing between 50% and 73% of each country's
maximum abatement potential.
Several limitations are worth noting in the croplands'
analysis. Coverage was limited to major crops. In
particular, rice was addressed separately and pasture
was excluded. As a result, the mitigation potential,
compared with the sector baseline as a whole, is limited.
Global Non-C02 Greenhouse Gas Emission Projections & Mitigation: 2015-2050 61

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Rice Cultivation
Source Background
Rice cultivation consists of CH4 emissions from rice production.
The anaerobic decomposition of organic matter (i.e.,
decomposition in the absence of free oxygen) in flooded
rice fields produces CH4. When fields are flooded, aerobic
decomposition of organic material gradually depletes the oxygen
present in the soil and flood water, causing anaerobic conditions
in the soil to develop. Once the environment becomes anaerobic,
CH4 is produced through anaerobic decomposition of soil organic
matter by methanogenic bacteria. Several factors influence the
amount of CH4 produced, including water management practices
and the quantity of organic material available to decompose.
Historical Trends
Between 1990 and 2015, CH4 emissions from rice cultivation
increased by 4%. Global emissions from rice cultivation increased
only slightly from 1990 through 2010 and remained relatively
stable through 2015. Underlying this trend is the production
of rice in non-OECD Asia. Non-OECD countries in Asia are the
primary producers of rice, accounting for over 80% of global
emissions from rice cultivation annually from 1990 through 2015.
Therefore, rice production in China, India, Vietnam, Indonesia,
and Thailand influenced historical trends in emissions from this
source.
2030 Emissions by Gas and Subsource
Non-CSBCD Asia is- projected to be the la rgest source of rice
cultivation emissions compared with other regions at 84%.
Non-OECD' Europe and Eurasia and the Middle East are
projected to be the Smallest sources of emissions from rice
cultivation in 2Q30 (Jess than lift-each).
Gas	Region
100
CH4(100%)	Middle East (<1%)
Non-OECD Europe and
Eurasia (<1%)
Central and South
America (4%)
Africa (5%)
OECD (7%)
Non-OECD Asia (84%)
Projected Emissions &Top Emitting Countries
Emissions (MtC02e)	2030 Emissions from Top 5 Emitting Countries
from 2QT5th rough 2030, CH%ertiiss:iOn;S'	Rest ofWorld: 192 MtC02e
from rice cultivation are projected to
decrease by 1 fk
Top 5 Emitters
China
India
Vietnam
Indonesia
Thailand
1990 2000 2 0 1 5 2 0 3 0 2050
Emissions (MtC02e)
Key Points
•	Rice cultivation is projected to account for 4% of total
non-C02 emissions by 2030.
•	Non- OECD countries in Asia accounted for approximately
84% of global rice cultivation emissions annually from
1990 through 2015.
•	From 2015 through 2030, emissions are expected to
decrease by 1%, largely due to increases in yield (i.e., rice
produced per hectare) and decreased per capita demand
for rice in the non-OECD Asia region.
Projected Trends
From 2015 through 2030, CH4 emissions from rice
cultivation are projected to decrease by 1 %. This
decreasing trend in emissions is driven largely by
projected emission reductions in China, one of the top
emitting countries for this source across the time series.
This projection assumes an overall decrease in rice area
harvested over the projection period. Rice area harvested
is the most important determinant of rice CH4 emissions.
Emissions are expected to decrease in non-OECD Asia
due to increases in yield, which can decrease the need
for area expansions Emissions are expected to increase
in other countries, such as non-OECD countries in Africa,
because the demand for rice is expected to increase in
these countries to sustain growing populations.
In addition, dietary preferences are also influencing
trends in emissions from rice cultivation. As economies
grow and middle- to high-income populations increase
in non-OECD countries, dietary preferences are expected
to shift from rice to protein^This dietary change is
expected to reduce the demand for rice and thereby
reduce emissions.
The non-OECD Asia region is expected to continue to
produce the vast majority of CH4 emissions from rice
cultivation, accounting for approximately 84% of the
emissions for this source in 2030. The largest contributors
in this region are China and India, which are estimated to
be the top emitting countries in 2030. While emissions
from multiple countries in the non-OECD Asia region are
expected to decrease over the projection period because
of the factors described above, emissions from other
major emitting countries in non-OECD Asia are expected
to increase to meet the growing demand for rice.
Global Non-C02 Greenhouse Gas Emission Projections & Mitigation: 2015-2050 63

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Key Points
The technologically feasible reduction
potential from rice cultivation is 221 MtC02e
in 2030,36% of baseline emissions.
India is the second highest emitter but offers
the highest global abatement potential.
Cost-effective abatement potential ($0
break-even price) is 62 MtC02e, or 28% of
total abatement potential.
A $20 break-even price contributes to 54%
of the rice cultivation abatement potential
in 2030.
Abatement Measures
For rice cultivation, this analysis considered
five management categories with various
application techniques: paddy flooding
(continuous flooding, midseason drainage [MD],
alternating wetting and drying [AWD], and
dryland production), crop residue incorporation
(50% and 100%), tillage (conventional and
no-till), fertilization application (conventional,
ammonium sulfate, nitrification inhibitor, slow-
release, reduced use, and auto-fertilization), and
direct seeding. Rather than considering each
management technique separately, the analysis
combined different techniques to assess the
best combinations to abate emissions from rice
cultivation.
Different management methods can be applied
to rain-fed or irrigated fields and, in some
cases, both. For paddy flooding, mid-season
draining and alternating between wetting
and drying are applicable to irrigated rice. In
contrast, continuous flooding and use of dryland
production are applicable to both field types.
Farmers use direct seeding in both field types by
flooding the rice paddy 40 days after planting
and draining the field 10 days before harvesting.
Properly managing tillage, residue, and fertilizer
techniques is crucial for growing a quality crop
while reducing GHG emissions. Conventional
tillage tills 20 cm deep before the first crop
rotation and 10 cm deep for following rotations,
whereas no-till mulches the residue and does
not till the land. Residue incorporation leaves
either 50% or 100% of the above-ground residue
to be incorporated in the next tillage. Nitrogen
fertilizers are applied in the form of urea or
ammonium sulfate and sometimes alongside
nitrogen inhibitors.
Total Reduction Potential
Abatement potential is 221 MtCQj© in 2030,38® of which is feasibleat no
cost, .Note that the baseline'of 617	NjO
emissions from rice cultivation are included in the croplands section baseline,-
64%
Baseline: 624 MtCO.fe -
64%
Baseline: 617 MtCO e -
67%
2020
2030
2050
Baseline: 602 MtCO.e ¦
Reductions at
No Cost
Technically Feasible
at Increasing Costs
Residual
Emissions
Reduction Potential by Technology
¦A total of 36 abatement measures were1 modeled for rice-cultivation, but the
top 10 measures comprise 64% of abatement potential. Across all abatement
measures, 2816 of abatement is aval la ble at costs WowsSQ/tCO-Mt
MD With Nitrification Inhibitor Fertilizer
AWD With Nitrification Inhibitor ||
No Till |
Dryland Rice With 20% Reduced Fertilizer
Dryland Rice
30% Reduced Fertilizer
Auto-Fertilization
AWD With Slow Release
MD With Slow Release Fertilizer
20% Reduced Fertilizer
MD With Ammonium Sulfate Fertilizer
MD With 30% Reduced Fertilizer
Other Measures
0
10
20
50
30 40
MtC02e
Reductions achievable at costs less than $0/tC02e
Reductions achievable at costs greater than $0/tC02e
70
64
Marginal Abatement Cost Curves, 2030
Taken together, the top 5 countries in terms of emissions represent 69% of baseline emissions from rice cultivation and 55% of
abatement potential. China, the top emitting country, represents 33% of baseline emissions alone.
$100 r
China
India
Vietnam
$100 r
$100 r
$80
$60
$40
$20
$0
-$20
Indonesia
Thailand
20	40
$100
$40 -
$20 -
$0 -
-$20 ¦
Rest of World
$ioo -
$80 -
$60 -
$40 -
$20 -
$0
-$20
-$40
W
Abatement Potential
To estimate abatement potential for this analysis,
we used a modified version of the DNDC 9.5 global
database to simulate crop yields and GHG fluxes from
global paddy rice cultivation systems. The model
estimates GHG fluxes (CH4, direct and indirect N20)
and changes in soil organic carbon. As a result, the
mitigation potential reflects reductions in CH4, N20, and
C02.
Many of the rice cultivation management techniques
focus on increasing soil carbon sequestration, but
sequestration capacity is limited. As soils reach their
maximum ability to sequester carbon, mitigation
may decline over time. This bears out in the modeling
results, which estimate a maximum mitigation potential
of 221 MtC02e in 2030,211 MtC02e in 2040, and
198 MtC02e in 2050. Nonetheless, roughly half of the
available abatement can be achieved at relatively low
prices. Approximately 28% of the potential abatement,
or 62 MtCQ2e, can be abated at prices below $0/tCO2e
in 2030 with an additional 26% reduction from baseline
available at prices between $0 and $20/tCO2e.
Globally, using mid-season drainage with nitrification
inhibitor fertilizer is the management technique with
the highest abatement potential in 2030. This measure
has the potential to cost-effectively deliver 4 MtC02e
and offers an additional 17 MtC02e for break-even
prices above $0/tCO2e. The second management
technique with the highest abatement potential is
alternating wet and dry with nitrification inhibitor.
This abatement measure can potentially mitigate
20 MtC02e in 2030, which is 3% of baseline emissions.
China, India, Vietnam, and Indonesia are the top
4 emitters from rice cultivation and are valuable
sources of potential abatement. In 2030, each country
can abate between 24 MtC02e and 38 i\/ltC02e,
respectively. Furthermore, 55% of rice cultivation's
global abatement potential in 2030 comes from these
four countries, 17% directly from India. All four nations
offer cost-effective mitigation options. At break-even
prices less than $0/tCO2e, India and Vietnam abate
14% and 27% of their national potential, respectively,
while Indonesia abates 48%.
Global Non-C02 Greenhouse Gas Emission Projections & Mitigation: 2015-2050 65

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Introduction
The waste sector is the third largest contributing sector
to global emissions of non-C02 GHGs, accounting for
13% of global non-C02 emissions in 2015. This section
presents global waste-sector CH4 and N20 historical and
projected emissions and the mitigation potential from
the following source categories:
•	Landfills (CH4)
•	Wastewater (CH4, N20)
Projections and MAC curves were estimated for all
sources. Emissions from landfills increased 19% between
1990 and 2015, growing from 56% to 59% of emissions
from the waste sector during this time frame. Waste-
sector emissions increased 13% between 1990 and 2015.
Between 2015 and 2030, emissions from landfills are
projected to grow more quickly than emissions from
wastewater, increasing 30% compared with 14%
growth for wastewater. During this time period, global
waste-sector emissions are projected to increase 23%
under a BAU scenario, reaching 1,905 MtCG2e in 2030.
Increases in population and per capita waste generation
drive global waste emissions upward, but historical
implementation of waste-related regulations and gas
recovery and use has tempered this increase.
Historical and Projected Emissions from the Waste
Sector
2,500
2,000
u
£ 1,500
u3 1,000
U
2 500
1990
2000
2015 2030
Landfills
2050
Other Waste
Wastewater
Mitigation potential from the waste sector is estimated
to be approximately 887 MtC02e in 2030. This mitigation
potential is 53% and 37% of landfill and wastewater
emissions, respectively; 47% of waste-sector emissions;
and 23% of total global non-C02 mitigation potential in
that year.
Emission Reduction Potential, 2030
12%	35%	53%
Baseline: 1,905 MtC02e	\
¦ Reductions at No Cost	| Technically Feasible at Increasing Costs	¦! Residual Emissions
Global Non-C02 Greenhouse Gas Emission Projections & Mitigation: 2015-2050 67

-------
2030 Emissions by Gas and Subsource
MSW includes household, garden :and park, commercial,
and institutional waste. Industrial waste includes organic
process waste generated by industry, which is not collected
in the MSW stream. MSW is the primary soiinSSof landfill
CH4emissions,accounting for between 709ttand SOffiaf
emissions from landfilling from 1990 through 2030;*
Key Points
Between 1990 and 2015, global CH4 emissions from
landfilling of solid waste increased by 19%.
Landfill emissions are estimated to increase by an
additional 30%, accounting for about 9% of global
BAU emissions in 2030.
Driving factors for landfill emission trends include
growing populations, increases in personal income,
and urbanization.
Subsource
CH4(100%)
Industrial (28%)
MSW (72%)
Projected Trends
Despite stable or even increased waste generation in
many OECD countries, landfill emissions from OECD
countries are projected to remain relatively flat, increasing
about 4% from 2015 through 2030, with an associated
decrease in their global contribution to total landfill
emissions from 32% to 25% by 2030. The decline in the
proportion of landfill emissions from OECD countries is
due to this region's relatively lower population growth
and use of landfill disposal compared with other
regions. The landfill emission projection methodology
assumes constant per capita waste generation and
landfill disposal proportions over time, based on the
most recently available country-reported or IPCC default
data. The projections, therefore, capture the effect of
current practices (i.e., based on policies and programs
implemented historically, such as landfill gas collection
policies or programs to limit the quantity of organic
waste that can enter solid waste facilities) but do not
include additional, future measures. Differences in
projected emissions across regions are driven primarily by
differences in current waste management practices and
future population growth.
In other regions, emissions from landfilling solid waste
are projected to increase at a greater rate. Regions
showing high growth in landfill emissions between 2015
and 2030 include Asia with an estimated 56% increase in
emissions by 2030, Africa (42%), and Central and South
America (36% and 24%, respectively). Asia's contribution
to global emissions is projected to increase to nearly
50% by 2030 compared with a 35% contribution in
2015. The combined effects of rapid economic change,
expansive growth policies, and population growth,
particularly in urban centers, are expected to increase
consumption, leading to higher waste generation.
In addition, to improve overall waste management,
these regions are expected to transition from open or
otherwise unmanaged dumpsitesto managed landfills,
thereby increasing landfill gas production and potential
emissions from landfills.
Landfills
Source Background
Landfilling of solid waste includes emissions associated with
the disposal of municipal solid waste (MSW) and industrial solid
waste. Landfills produce CH4 and other landfill gases, primarily
C02, through the natural process of bacterial decomposition of
organic waste under anaerobic conditions. Landfill gases are then
generated over a period of several decades, with flows usually
beginning within 2 years of disposal.
Historical Trends
Solid waste was the fifth largest contributor to global emissions
of non-C02 GHGs in 2015, accounting for about 8% of total
emissions.The amount of CH4 generated by landfills is determined
by key factors including population, the quantity of waste
disposed of per person, composition of the waste disposed of, and
the waste management practices applied at the landfill.
Between 1990 and 2015, global CH4 emissions from landfills
increased by about "19%. Over this period, landfill-related
emissions decreased in the European Union and other developed
countries by approximately 32%, driven by large reductions in
the use of landfills for final disposal combined with increased
deployment of landfill gas recovery. The overall growth in global
landfill emissions during the past 25 years has been driven by
population growth, economic development, and urbanization in
developing countries.
Projected Emissions &Top Emitting Countries
Emissions (ft/ltC02e)
From 2015 through 2030; CH4 emissions
from landfills are projected to increase
by 30%.
1,675
1990 2000 201 5 2 0 3 0 2050
Emissions (MtC02e)
2030 Emissions from Top 5 Emitting Countries
Rest of World: 695 MtCC^e
m

Top 5 Emitters
y
60
China
United States
Russia
Indonesia
' Brazil
68
Global Non-C02 Greenhouse Gas Emission Projections & Mitigation: 2015-2050 69

-------
Key Points
• Global abatement potential from landfills is
636 MtC02e, or 53% of projected baseline
emissions in 2030.
• Abatement measures with costs below
$0/tC02e can achieve a 19% reduction in
landfill baseline emissions.
• Electricity generation with a reciprocating
engine is the leading abatement measure in
2030, accounting for 12% of potential.
Total Reduction Potential
Reducing emissions by l:6fl€ compared with the 2020 baseline is eQSt-eJfeGtive,
An additional 3SS reduction is available using technologies with increasingly
higher costs.TheeGst-effectlve reduction potential rises to 79% in 2030 and to
20% tn 2650.
Abatement Measures
This analysis considers 12 abatement options
to control landfill emissions, which are grouped
into three categories: (1) collection and flaring,
(2) landfill gas (LFG) utilization systems (LFG
capture for energy use), and (3) enhanced waste
diversion practices (e.g., recycling and reuse
programs).
Collection of LFG is feasible at most engineered
landfills. It prevents high concentrations of gas
in the landfill, which addresses public health and
facility safety concerns. After collecting LFG, the
least capital-intensive way to reduce emissions is
flaring, which burns off the gas. However, flaring
does not deliver any economic benefits for
landfill operators.
Energy production represents a potential
revenue stream for landfills. It includes electricity
generation, anaerobic digestion, and direct use.
A variety of engine types and waste-to-energy
processes can achieve electricity generation.
Anaerobic digestion provides CH4 for on-site
electricity or for selling to the market. Direct
use implies that a landfill transports captured
methane to a facility, which uses it for electricity
generation, as process heat, or as an input into
other processes.
Furthermore, enhanced waste diversion practices
redirect biodegradable components of the
waste stream from the landfill for reuse through
recycling or conversion to a value-added product
(e.g., energy or compost). Diverting organic
waste components lowers the amount of CH4
generated at the landfill. Other benefits from
the measures under this category include the
sale of recyclables, electricity, and cost savings in
avoided tipping fees.
16% 35%
Baseline: 992 MtCO,e.
49%
19% 35%
Baseline: 1,191 MtC02e -
47%
49%
2020
2030
2050
Baseline: 1,675 MtCO,e-
Reductionsat
No Cost
Technically Feasible
at Increasing Costs
Residual
Emissions
Reduction Potential by Technology
In 2818, landfill gas recovery for direct use is the leading emission abatement
measureat SO/tCOje; flaring offers the highest abatement potential at higher
pricfis. Overall, elestrteitl? generation measures comprise the largest share of
potential abatement with 31 MtCQjS
Electricity Generation With a Reciprocating Engine
Flaring of Landfill Gas
Waste to Energy
Composting
Mechanical Biological Treatment j
Paper Recycling
Anaerobic Digestion
Landfill Gas Recovery for Direct Use
Electricity Generation With Combined Heat and
Power
Electricity Generation With a GasTurbine
Electricity Generation With a Microturbine
Enhanced Oxidation
0
10 20
30 40 SO
MtC0,e
70 80
Reductions achievable at costs less than $0/tC02e
Reductions achievable at costs greater than $0/tC02e
70
Marginal Abatement Cost Curves, 2030
Taken together, the'top Scountries in terms of emissions-represent 23®&of all potential global abatement from landfills in 2030.
The United States Is the second largest emitter in the world, but Its maximum potential abatement is lower compared: with other
countries because of high levfels of prior adoption of abatement measures,
United States
Russia
China
i
Indonesia
Rest of World
Abatement Potential
Global abatement potential from solid waste landfills is
estimated to be approximately 635 MtC02e in 2030, or
53% of the baseline emissions. Slightly more than half
of all potential abatement can be achieved at break-
even prices below $20/tCO2e; 31% of reductions can
be achieved at prices below $0/tCO2e, suggesting a
substantial share of abatement could generate revenue
for landfill operators.
At a global level in 2030, the measures that contribute
the highest potential to reduce emissions are
electricity generation with a reciprocating engine
(78 MtC02e), flaring of LFG (67 MtC02e), and waste to
energy (60 MtC02e). Other types of energy generation
(electricity using combined heat and power, gas
turbines or microturbines, and direct use of LFG) add
an additional 123 MtC02e of abatement potential.
Other enhanced waste diversion practices represent
307 MtC02e of potential abatement.
Russia, Indonesia, and Brazil have the highest
abatement potential, contributing to 18% of the
global potential in 2030. These nations are the third,
fourth, and fifth top emitters. Russia's, Indonesia's, and
Brazil's mitigation potential from landfills is 51 MtC02e,
35 MtC02e, and 28 MtC02e, respectively. These nations
can reach between 20% and 26% of national potential
with break-even prices below $0/tCO2e.
China and the United States are the top 2 emitters and
collectively can mitigate 5% of total landfill emissions
in 2030—27 MtC02e in China and 8 MtC02e in the
United States.The United States already has a high rate
of adoption of abatement measures, leading to a lower
future mitigation potential
Global Non-C02 Greenhouse Gas Emission Projections & Mitigation: 2015-2050 71

-------
Wastewater
Source Background
Wastewater originates from a variety of residential, commercial,
and industrial sources. It can be a source of CH4 when organic
material present in the wastewater-flows decomposes under
anaerobic conditions. Developed countries rely on centralized
aerobic wastewater treatment systems that limit CH4 generation,
while developing countries often rely on a broader suite of
wastewater treatment technologies. N20 emissions occur
primarily as indirect emissions from wastewater after disposal of
effluent into waterways, lakes, or the sea.
The quantity of degradable organic material in the wastewater
and the type of treatment system are the key drivers of
wastewater CH4 emissions.The nitrogen content in the
wastewater effluent is the key driver for indirect N20 emissions.
Historical Trends
Wastewater accounted for 5% of global non-C02 emissions in
2015. Between 1990 and 2015, global CH4 and N20 emissions
from wastewater disposal and treatment increased by 4%. CH4
emissions decreased by 6% during this period, whereas indirect
N20 emissions increased substantially on a percentage basis
over the same period—69%. Since 1990, the share of wastewater
emissions from large urban populations with more access to
wastewater treatment has increased compared to the emissions
from rural areas, as urbanization has increased globally.
2030 Emissions by Gas and Subsource
CH^emissibrisaccoiint for about of projected
wastewater emissions, while N jO emissions acrount for the
remaining 21% Urban wastewater emissionsare projected to
increase by nearly Si p£r year ccfmpafed with a decrSaseef
CL3f&annually for rural wastewater amissions^
Gas
Subsource
100
N20 (21%)
CH4 (79%)
Rural (32%)
Urban (68%)
Projected Emissions &Top Emitting Countries
Emissions (MtC02e)
From 201S through 2
-------
Key Points
•	The maximum abatement potential in
2015 is 122 MtC02e, or 20% of projected
emissions.
•	By 2030, the abatement potential is
expected to reach 251 MtC02e, or 37% of the
projected baseline.
•	Close to 10% of baseline emissions can be
abated at break-even prices of less than
$50/tC02e.
Abatement Measures
Upgrades to infrastructure and equipment
can reduce CH4 emissions from wastewater.
No proven and reliable technologies for
mitigating N2Ofrom wastewater treatment exist.
Abatement measures available for wastewater
include (1) implementing centralized collection
of wastewater for treatment, (2) constructing
aerobic wastewater treatment plants (WWTPs),
and (3) constructing anaerobic WWTPs with
cogeneration.
Country-specific factors, including economic
resources, population density, government,
and technical capabilities, are important in
determining the mitigation potential for this
source. A country's desire and capacity for
improved sanitation are the primary drivers of
the adoption of these technologies, and CH4
mitigation is a secondary result. This analysis
does not include the value of health benefits
resulting from improved sanitation, which may
affect the mitigation estimates.
This report quantifies the mitigation potential
of replacing latrines, open sewers, and septic
tank use with anaerobic WWTPs. These three
infrastructure improvements provide a
significant amount of mitigation for costs below
and above $0/tCO2e. Replacing latrines offers the
highest abatement potential because they are
better than using no sewage treatment. Latrines
are common in developing countries, presenting
a low-cost abatement option.
This analysis also considers the mitigation
potential of a WWTP that uses an anaerobic
sludge digester with co-generation. However,
adding co-generation increases the capital cost
of the technology. Thus, this measure is found
mostly in developed countries.
Total Reduction Potential
There are1 no- emission reductions available from wastewater at prices- below
SO/tCOjBin 2020. At increasing.costs,a JS^J reduction in emissions is possibte
Theemissions reduction potential at incteising costs rises to Sf% in 2030.'
Marginal Abatement Cost Curves, 2030
Taken together, the'top Scountries in terms of baselinesmissions represent 48% of all potential global abatement for this source
in 2CJ®. China is the highest emitting country but also- contributes to TIH of global abatement potential for this source, or
39 MtCOjS,. in .2030,
Indonesia
75%
Baseline: 632 MtCO.e
Baseline: 685 MtCO,e
2020
2030
2050
Baseline: 758 IVltC02e ¦
Reductions at
No Cost
Technically Feasible
at Increasing Costs
Residual
Emissions
Reduction Potential by Technology
In 2030, switching from latrlnestoaetobic WWTPs is the leading emission
abatement measure with the potential to reduceemissions by 116 MiCtljs.
Switching from open sewers to lerobic WWTPs is the only measure that offers
reductions at costs less than $0/tCOj&
Latrine to Aerobic WWTP
Open Sewer to Aerobic WWTP
SepticTank to Aerobic WWTP
Wastewater Treatment Plant With Anaerobic
Sludge Digester With Co -gen
20 40 60 80 100 120
MtC02e
Reductions achievable at costs less than $0/tC02e
Reductions achievable at costs greater than $0/tC02e
Rest of World
S_ Iran
10 20 30
40 50 60
Abatement Potential
The global abatement potential of CH4from wastewater
treatment is 122 MtC02e in 2015 and rises to 251 MtC02e
in 2030. High-cost abatement measures from wastewater
treatment significantly constrain the abatement
achievable at lower prices. Cost-effective emission
reductions, or reduction at prices below $0, are limited to
2 MtC02e, less than 1% of BAU emissions in 2030.
At the global level, the top abatement measures
require shifting from using latrines and open sewers
to implementing centralized collection with aerobic
WWTPs. The installation of these plants costs $97 million
per plant and has an annual maintenance cost of
$4.7 million, making these an expensive abatement
option. However, the improved sanitation and
mitigation potential makes aerobic WWTPs worthwhile
investments. Shifting from latrine use to aerobic
WWTP has the highest mitigation potential, reaching
116 MtC02e, or 17% of baseline emissions. Shifting
from using open sewers to using aerobic WWTPs is the
second-best abatement measure and has the potential
to abate 85 IVitC02e in 2030. All abatement measures
from wastewater offer 60% to 80% reduction efficiency.
China, Indonesia, and India are the countries with the
highest mitigation potential in 2030 across all abatement
measures. These countries have the potential to mitigate
39 MtC02e, 32 MtC02e, and 26 MtC02e, respectively.
The three countries contribute to 39% of the global
abatement potential, with 16% coming from just China.
None of these countries have cost-effective abatement
measures at a zero price; however, each country can
potentially reach 22% to 27% of its mitigation potential
with break-even prices less than $20/tCO2e. Switching
from latrine usage to aerobic WWTP is the leading
abatement measure for all three countries. This measure
can potentially mitigate 29 MtC02e in China and drive
74% of that nation's overall potential in 2030. Switching
from open sewer usage to aerobic WWTPs is the second
most influential abatement technology in each of these
countries.
Wastewater
74
Global Non-C02 Greenhouse Gas Emission Projections & Mitigation: 2015-2050 /5

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8	See endnote 1.
9	See endnote 2.
10	See endnote 4.
11	Although this document is published by the EPA, the U.S.
projections were generated using the same methodologies used
for all countries. The BAU projection does not explicitly model the
effects of current or proposed policies.
12	Historical reported emission estimates are available at varying
years for each country between 1990 and 2016.
13	Intergovernmental Panel on Climate Change. 2006.2006IPCC
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14	Disaggregation of CH4 from coal mining by mine type was based
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country-reported data.
15	U.S. Energy Information Administration. 2017. International
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16	Emissions from the energy sector were projected using data from
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EIA scenario considers current policies and incorporates certain
specific details of commitments under international climate
agreements such as renewable energy and energy mix goals, but
uncertainties about how commitments would be implemented
or achieved can limit the extent to which each can be modeled in
ElA's projections.
17	See endnote 15.
18	Ibid.
19	Disaggregation of CH4 from natural gas and oil systems by
industry segment was based on default calculations and may not
be consistent with country-reported data.
20	See endnote 15.
21	International voluntary programs encourage efforts to reduce
CH4 emissions without reducing energy production, and progress
has been made historically to control these emissions. Mitigation
efforts were included in the BAU projection to the extent they
are included in historical country-reported inventories, but the
projections do not model future changes in control from policies
or voluntary actions. For example, at the time of this writing, the
United States is considering changes to New Source Performance
Standards (NSPS) that affect emissions from natural gas and oil
systems, but the projections in this report do not model either
current or proposed policies, and more granular analysis would be
required to assess policy impacts such as the NSPS.
22	U.S. New Source Performance Standards. Available online at
https://www.govinfo.gov/content/pkg/CFR-2011 -ti 11 e4 0-vo 16/
xml/CFR-2011-title40-vol6-part60.xml
23	U.S. Energy Information Administration. 2018. International
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oiaf/ieo/index.html
24	Ibid.
25	U.S. Environmental Protection Agency. 2006. Recommended
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EPA. Available online at https://www.epa.gov/natural-gas-
star-program/recommended-technologies-reduce-methane-
emissions
26	Biomass fuels include wood fuel, charcoal, agricultural residues
and waste, and municipal waste.
27	Unlike C02 emissions, biomass combustion does in all cases result
in net additions of CH4 and N20 to the atmosphere.
28	See endnote 16.
29	U.S. Energy Information Administration. 2018. International
Energy Statistics. Online Database. Available online at https://
www.eia.gov/cfapps/ipdbproject/IEDIndex3.cfm
30	Disaggregation of CH4 and N20 emissions from combustion
by fuel type was based on default calculations and may not be
consistent with country-reported data.
31	See endnote 15.
76
32	Ibid.
33	Ibid.
34	Ibid.
35	Food and Agriculture Organization of the United Nations. 2010.
Future Trends in Energy, Climate and Woodfuel Use. Rome: Food and
Agriculture Organization of the United Nations. Available online at
http://www.fao.Org/3/i1756e/i1756e05.pdf
36	See endnote 15.
37	United Nations Environment Programme. November 2013.
Drawing Down N20 to Protect Climate and the Ozone Layer: A UNEP
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Climate_and_the_Ozone_Layer_A_UNEP_Synthesis_Report
38	Climate Policy Watcher. November 2016. Nitrous oxide from adipic
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41	See endnote 37.
42	Disaggregation of N20 from this source category into nitric versus
adipic acid production was based on default calculations and may
not be consistent with country-reported data.
43	IHS Markit. June 2017. Chemical Economics Handbook: Adipic Acid.
Available online at https://www.ihs.com/products/adipic-acid-
chemical-economics-handbook.html
44	Tenkorang, F. and J. Lowenberg-DeBoer. 2008. Forecasting
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45	Liu, J., K. Ma, P. Ciais, and S. Polasky. 2016. Reducing human
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46	See endnote 37.
47	Occams Business Research. May 2017. Global Nitric Acid Market
Insights, Opportunity, Analysis, Market Shares and Forecast 2017
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48	IHS Markit. December 2012. Bio-Based Adipic Acid. IHS Markit.
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49	See endnote 43.
50	Coherent Market Insights. May 2017. Global Adipic Acid
Market, by Application (Nylon 6,6 Fiber, Nylon 6,6 Resin,
Polyurethanes, Adipate Esters), End Use Industry (Automotive,
Electrical & Electronics, Home Appliances,Textiles, FMCG),and
Geography - Global Insights, Size, Share, Opportunity Analysis,
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market-318
51	Merchant Research & Consulting Ltd. January 2019. Adipic acid
(ADPA): 2019 world market outlook and forecast up to 2028.
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adpa
52	Ecofys, Fraunhofer ISIR (Institute for Systems and Innovation
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53	Schneider, L., M. Lazarus, and A. Kollmuss. 2010. Industrial N20
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54	See footnote 52.
55	See endnote 2.
56	U.S. Energy Information Administration. 2017. International
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57	IHSTechnology. November 2017. Display long-term demand
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58	IHS Markit. January 2015. Flat panel display area demand
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59	See endnote 56.
60	Emissions from PV manufacturing sources were projected using
activity data from ElA's International Energy Outlook Reference
Case scenario. This EIA scenario considers current policies and
incorporates certain specific details of commitments under
international climate agreements such as renewable energy and
energy mix goals, but uncertainties about energy sector policies
Global Non-C02 Greenhouse Gas Emission Projections & Mitigation: 2015-2050

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and trends would have large impacts on the underlying activity
data and resulting emissions from PV manufacturing.
61	Smythe. K. December 1-3,2004. Trends in SF6 Sales and End-Use
Applications: 1961-2003. International Conference on SF6and the
Environment: Emission Reduction Technologies, Scottsdale, AZ.
62	U.S. Energy Information Administration. 2016. International Energy
Outlook2016. DOE/EIA-0484(2016). Washington, DC: Energy
Information Administration, U.S. Department of Energy. Available
online at https://www.eia.gov/outlooks/ieo/pdf/0484(2016).pdf
63	Fang, X., X. Hu, G. Janssens-Maenhout, J. Wu, J. Han, S. Su, J.
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for China: An Inventory for 1990-2010 and a Projection to2020.
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64	Ibid.
65	Marks, J. and P. Nunez. 2018. Updated Factors for Calculating PFC
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66	U.S. Environmental Protection Agency. 2010. EPA's Climate
Protection Workshop for the Magnesium Industry. Available
online at https://www.epa.gov/sites/production/files/2016-02/
documents/1 -final_ima_sanfran_cappel.pdf
67	U.S. Geologic Survey. 1995 through 2016. Mineral Yearbook:
Aluminum statistics and information. Reston, VA: U.S. Geological
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pubs/commodity/aluminum/index.html#myb
68	Marks, J., industry expert at J Marks & Associates, LLC. May 2017.
Personal communication.
69	Roskill. 2016. Magnesium metal: Global industry, markets &
outlook. Available online at https://roskill.com/market-report/
magnesium-metal/
70	Ibid.
71	International Aluminium Institute. 2016. Results of the 2015
Anode Effects Survey: Report on the Aluminium Industry's Global
Perfluorocarbon Gases Emissions. London, UK: International
Aluminium Institute. Available online at http://www.world-
aluminium.org/media/filer_public/2016/08/08/2015_anode_
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72	U.S. Environmental Protection Agency. 2010. EPA's SF6 Emission
Reduction Partnership for the Magnesium Industry. Available
online at https://www.epa.gov/f-gas-partnership-programs/epas-
sf6-emission-reduction-partnership-magnesium-industry
73	World Meteorological Organization. 2019. Scientific Assessment
of Ozone Depletion: 2018. Report No. 58. Available online at
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downloads/20180zoneAssessment.pdf
74	See endnote 65.
78
75	Cooling Post. June 22,2019. Cuba becomes 73rd country to ratify
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76	United Nations Environment Programme. April 4-7,2017.
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77	Liu, Q., J. Wang, Z. Bai, L. Ma, and 0. Oenema. 2017. Global animal
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78	Robinson,T.P., P.K.Thornton, G. Franceschini, R.L. Kruska, F.
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79	Food and Agricultural Policy Research Institute. 2012. U.S. and
World Agricultural Outlook: Meat Outlook. Ames, IA: Food and
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80	Food and Agricultural Policy Research Institute. 2011. U.S. and
World Agricultural Outlook: Dairy Outlook. Ames, IA: Food and
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81	Organisation for Economic Co-operation and Development and
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82	Food and Agriculture Organization of the United Nations. 2017.
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83	MilovanovicV.,and S. Lubos. 2017. Asian countries in the
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84	Wailes, E. J. and E.C. Chavez. March 2016. International Rice
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85	Disaggregation of emissions from landfills by landfill type was
based on default calculations and may not be consistent with
country-reported data.
86	Disaggregation of emissions from wastewater by geographic
region was based on default calculations and may not be
consistent with country-reported data.

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United States Environmental Protection Agency
Office of Atmospheric Programs (6207A)
Washington, DC 20005

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