Global Methane Emissions
and Mitigation Opportunities
Why Target Methane?
Methane is the second most abundant anthropogenic greenhouse gas (GHG) after carbon dioxide (CO2), accounting for about 20
percent of global emissions. Methane is considered a “short-term climate forcer,” meaning it has a relatively short lifespan in theatmosphere of approximately 12 years. Though methane is in the atmosphere for a shorter period of time and is emitted in smaller
quantities than CO2, its global warming potential (i.e., the ability of the gas to trap heat in the atmosphere) is 28-34 times greater.1
As a result, methane emissions contributed to about one-third of today’s anthropogenic GHG warming.
Methane is emitted during the production and transport of coal, natural gas, and oil. Emissions also result from the decay oforganic matter in municipal solid waste (MSW) landfills, some livestock manure storage systems, and certain agro-industrial andmunicipal wastewater treatment systems. Capturing methane from these sources offers a unique opportunity to mitigate climatechange and simultaneously increase energy security, enhance economic growth, and improve air quality and worker safety.

Ü G lobal Methane Emissions

Figure 1: Estimated Global Anthropogenic
Methane Emissions by Source, 2020

by Sector

Global anthropogenic methane emissions
by 2020 are estimated to be 9,390 million
metric tons of CO2 equivalent (MMTCO2E).2
Approximately 54 percent of theseemissions will come from the five sources
targeted by the Global Methane Initiative(GMI): agriculture (manure management),
coal mines, MSW, oil and natural gas
systems, and wastewater (see Figure 1).

Rice Cultivation 7%
Stationary &Mobile Sources 4%
Biomass 3%
Other Ag Sources 5%

Ü Global Emissions Projections
Global anthropogenic methane emissions areprojected to increase by nearly 9 percent overanticipated 2020 levels to 10,220 MMTCO2E by2030 (see Figure 2).
From 2020 to 2030, the relative proportions ofthe agriculture (manure management), coalmines, and wastewater sectors are projected to2	The fifth report of the Intergovernmental Panel on Climate Change (IPCC), released
in 2013, included methane GWP values of 28 to 34. The United States and other developed countries are currently using the fourth report’s GWP value of 25 to quantify
the climate impact of U.S.-government-supported methane reduction projects.

Coal Mining 9%
Municipal Solid
Waste 11%

Oil & Gas 24%

Figure 2: Estimated and Projected Global Anthropogenic
Methane Emissions by Source, 2020 and 2030

3000

Enteric Fermentation

2500
2000
Municipal
Solid
Waste

1500
1000

Wastewater

Other Ag
Sources500
0-500

Oil andGas

Coal
MiningEstimated 2020 Emissions

Unless otherwise noted, all data are from U.S. Environmental Protection Agency’s(U.S. EPA’s) Global Anthropogenic Emissions of Non-CO2 Greenhouse Gases:
1990–2030 report. www.epa.gov/climatechange/Downloads/EPAactivities/
EPA_Global_NonCO2_Projections_Dec2012.pdf.

Global Methane Initiative

Agriculture (ManureManagement) 3%

Wastewater 7%

GMI Partner Countries (see www.
globalmethane.org for complete list)
represent approximately 70 percent of theworld’s estimated anthropogenic methane
emissions. Partner countries’ major methane
emission sources vary greatly, and thus theopportunities for methane capture and use ineach country also vary.

1	Enteric Fermentation 27%

1

Rice
Cultivation

ManureManagement

Stationary& Mobile

Biomass

Projected Added Emissions by 2030

www.globalmethane.orgÜ Benefits of MethaneFigure 3: Global Anthropogenic Methane Emissions, 1990 - 2030
6000
5000

MMTCO2E

remain constant, while emissions fromMSW and the oil and gas sectors areexpected to increase by approximately
one percent of estimated global
anthropogenic methane emissions (seeFigure 3). Within each sector, methane
emissions from agriculture, MSW,
and wastewater treatment systems
are expected to increase by 5, 6, and8 percent respectively. Oil and gas
emissions are estimated to increase by
11 percent over current levels. Finally,emissions associated with coal mines
are expected to increase by 17 percent
from 2020 to 2030.

4000
3000
2000
100001990
Agriculture

2000
Coal Mines

2010

Municipal Solid Waste

20202030

Oil & Gas

Wastewater

Mitigation

Cost-effective mitigation technologies
and practices to address methane
emissions from the largest
anthropogenic sources are alreadywidely available and in use all over
the world.3 In addition to mitigatingclimate change, reducing methane
emissions delivers a host of otherenergy, health and safety, andlocal environmental benefits. Manytechnologies and practices that
reduce methane emissions also
reduce emissions of volatile organic
compounds, hazardous air pollutants,
and other local air pollutants. This
yields health benefits for local
populations and workers. Because
methane is an important precursorof tropospheric ozone, reducing
methane also reduces ozone-related
health effects.
Methane reduction projects at landfills
and wastewater treatment plants
also reduce odors; in the agriculture
sector, they control manure, protect
local ecosystems, and reduce odors.
Capturing methane from gassy coalmines improves industrial safety byreducing the risk of explosions. The useof low-emission equipment and better
management practices in oil andnatural gas systems minimizes methaneleaks, yielding health and safety
benefits while increasing efficiency,thus generating increased revenue.
For any project, recovering
methane provides a local sourceof clean energy that can spur
economic development anddisplace higher CO2- and pollutantintensive energy sources such aswood, coal, and oil. Recovered
methane can also serve as a newsustainable and abundant energy
source for developing countries.

Ü Overview of Mitigation

Opportunities

The Global Methane Initiative
The Global Methane Initiative (GMI) is avoluntary, multilateral partnership thataims to reduce global methane emissions
and to advance the abatement, recovery,
and use of methane as a clean energy
source. GMI achieves this goal by creating
an international network of partner
governments, private sector members,
development banks, universities and nongovernmental organizations to conduct
assessments, build capacity, createpartnerships, and share information tofacilitate project development for methane
reduction in GMI Partner Countries.

Many of the currently available
methane mitigation opportunities
involve the recovery and use ofMore than 1,000 public and private sector
methane as fuel for electricity
organizations are members of the GMI
generation, onsite uses, or offsite
Project Network, and have helped thegas sales. Specific technologies andprogram to leverage nearly $600 million
mitigation approaches, however,in investment from private companies andvary by emission source because of
their different characteristics andfinancial institutions.
emission processes. The matrix (onpage 3) provides a brief summaryof the mitigation opportunities bysector, as well as examples of mitigation
technologies from Partner Countries.

The Fourth Assessment Report of Working Group III of the IPCC (www.mnp.nl/ipcc/pages_media/AR4-chapters.html) and the U.S. EPA report, Global Mitigation of Non-CO2
Greenhouse Gases (www.epa.gov/climatechange/economics/international.html), both contain information on methane mitigation options.

3

Global Methane Initiative2

www.globalmethane.org

Sources of Methane

Agriculture (ManureManagement)

GlobalMethane
Emissionsper Sector*
286
MMTCO2E

Produced from decomposition of livestock and poultry
manure stored or treatedin systems that promoteanaerobic conditions (e.g.,liquid or slurry in lagoons,ponds, tanks, or pits).

Coal Mines
Emitted from active andabandoned undergroundmines and surface mines,
and as a result of postmining activities including
coal processing, storage,and transportation.

Municipal Solid Waste
Produced through thedecomposition of organic
waste under anaerobic
conditions typically foundin landfills and large dumpsites.

Oil & Gas Systems
Emitted during normal
operations, routine maintenance, and system disruptions in the oil and natural
gas industry.

Wastewater
Produced by decay oforganic material in wastewater as it decomposes inanaerobic environments.

Proven Mitigation
Technologies

Mitigation Opportunities• Covered anaerobic lagoons collect and transmit

lagoon-generated biogas to a dedicated point fortransmission to some type of gas use device (e.g.,engine).

• Digesters (e.g., plug flow, complete mix) that compostor “digest” organic waste in the absence of oxygen,thereby generating methane for collection and use.

Floating Dome Anaerobic
Digester (India)

For more information from the Agriculture Subcommittee:
www.globalmethane.org/agriculture
799
MMTCO2E• Degasification, where holes are drilled and themethane is captured (not vented) in conjunction withmining operations.

• Ventilation air methane (VAM) abatement, wherelow concentrations of methane are oxidized togenerate heat for process use and/or electricity
generation.

For more information from the Coal Subcommittee:
www.globalmethane.org/coal-mines
1,077
MMTCO2E

Degasification Pump Station(Ukraine)• Extraction using a series of wells and a vacuum

system, which directs the collected gas to a point tobe combusted in a flare or utilized for energy (e.g.,
electricity generation, boiler, dryers, vehicle fuel).

For more information from the Municipal Solid Waste
Subcommittee: www.globalmethane.org/landfills
Landfill Gas Well(China)
2,276
MMTCO2E• Technologies or equipment upgrades that reduce oreliminate equipment venting or fugitive emissions.

• Enhanced management practices that take advantage of improved measurement or emission reduction technology.

For more information from the Oil and Gas Subcommittee:
www.globalmethane.org/oil-gas
672
MMTCO2E

Leak Detection Equipment(Mexico)Installation of:• Anaerobic sludge digestion (new construction or
retrofit of existing aerobic treatment systems).

• Biogas capture systems at existing open air anaerobiclagoons.

• New centralized aerobic treatment facilities or covered lagoons.

• Gas capture and combustion systems to flare or utilize

methane (e.g., onsite electricity or other thermal uses).

For more information from the Wastewater Subcommittee:
www.globalmethane.org/wastewater

Anaerobic Wastewater
Treatment (Chile)

estimated annual 2020 emissions*

Global Methane Initiative3

www.globalmethane.orgÜ Emission Reduction

Potential by Sector

Methane emissions can be relatively
inexpensive to reduce compared with
CO2, and various government agencies
and organizations are incorporating
non-CO2 mitigation into analysis andpolicy discussions. U.S. EPA’s Global
Mitigation of Non-CO2 Greenhouse Gas
report conducted an analysis applying
currently available mitigation options
and technologies to global methane
emission baselines in the five GMI
target sectors to provide insight intomethane emission reduction potentialand costs. 4• Agriculture (ManureManagement): Has an increasing
reduction potential of 3 to 10
percent associated with raising
activity costs from $15 to $30/MTCO2E. Increasing costs to $60
generates an additional 5 percent
abatement but at diminishingmargins of return per cost increase.
The global abatement potential orGAP (at any cost) is only 28 percentof the baseline.

• Coal Mines: 56 percent of potential
reductions—which represents
nearly all of the sector’s GAP—
could be achieved by increasing
costs from $0 to $15/MTCO2E,
above which the potential for
reductions remains steadyregardless of increased activity
cost.

• MSW: Has an emission reduction

potential of more than 25 percent
with a minimal $15/MTCO2E
investment, but remains relatively
constant per cost increment from$30 to $60/MTCO2E. Another 30
percent increase in reduction
potential exists for activities costing
more than $60/MTCO2E, which
results in a GAP of 61 percent ofTable 1: Global Percentage Reduction from Projected Baseline, 2030

GlobalBaseline Abatement$0 $15 $30 $45 $60(MMTCO2E) Potential(at any cost)
Agriculture 0%
3% 10% 13% 15%384
28%
Coal Mining 10% 56% 59% 59% 59%78460%
Municipal
12% 26% 31% 32% 32%
959
61%
Solid Waste
Oil and Gas 35% 42% 44% 45% 47%
2,113
58%
Wastewater 1%3% 5% 7% 8%609
36%
Cost perMTCO2E

Source: Global Mitigation of Non-CO2 Greenhouse Gases: 1990 – 2020 (EPA Report 430-R-06-005)

the baseline—the greatest total
reduction potential of all sectors.

• Oil and Gas: Represents thegreatest near-term opportunity,with the largest emission reduction
potential of 35 percent resulting
from no-cost activities ($0/MTCO2E).
Increasing costs from $15 to $60/
MTCO2E generates an additional
5 percent, while achieving theremaining 11 percent to reach themaximum GAP requires costs inexcess of $60/MTCO2E.

• Wastewater: Could achieve a one

percent reduction potential at nocost ($0/MTCO2E), increasing up to
8 percent by raising activity costs
to $60/MTCO2E. Achieving thesector’s 36 percent GAP requires
costs in excess of $60/MTCO2E.

Overall, the methane mitigation
potential at or below $0/MTCO2E isapproximately 940 MMTCO2E. The
mitigation potential doubles to nearly
1,900 MMTCO2E as the price of theaction rises from $0 to $60/MTCO2E,
which accounts for more than 70
percent of the GAP from these fivesectors. The analyses also found thatthe largest methane emitters (e.g.,China, India, United States) show
significant mitigation potential in thelower range (e.g., $10/MTCO2E).

Ü Conclusion
There are many economically viable
opportunities worldwide to reduce
methane emissions. GMI serves as
an innovative mechanism to bring
together interested parties fromgovernment and the private sector
to overcome barriers and facilitate
methane project development
and implementation around theworld. By conducting technology
transfer, improving local capacity,and marketing project opportunities
across borders and sectors, theInitiative is promoting local, clean
energy resources while reducing GHGemissions.

For additional information, please visit
the GMI website at:www.globalmethane.org
or contact theGMI Administrative Support Group
Tel: +1-202-343-9683
E-mail: ASG@globalmethane.org

Complete details on the inputs and methodologies used in this analysis are fully described in U.S. EPA’s report Global Mitigation of Non-CO2 Greenhouse Gases: 2010 - 2030 at
http://www.epa.gov/climatechange/EPAactivities/economics/nonco2mitigation.html.

4 

Global Methane Initiative4

www.globalmethane.org