Global Methane Emissions and Mitigation Opportunities
ethane (CH4) is a hydrocarbon that is the primary component of natural gas. It is also a “greenhouse gas,” or GHG, meaning that its presence in the atmosphere can trap heat and thus affect the earth’s temperature and climate system. Methane is second only to carbon dioxide (CO2) as a GHG resulting from human activities. Methane is 23 times as effective at trapping heat in the atmosphere as CO2. It also has a relatively short atmospheric lifetime of approximately 12 years. These two characteristics make methane emissions reductions particularly effective at mitigating global warming in the near term (i.e., the next 25 years).
Partner Countries account for more than 60 percent of the global anthropogenic methane emissions from these four sources, and nearly 65 percent of total global anthropogenic methane emissions. Together, Methane to Markets Partners Brazil, China, India, Indonesia, Mexico, Russia, Ukraine, and the United States are estimated to be responsible for almost half of all global anthropogenic methane emissions.
Over the last two centuries, methane concentrations in the atmosphere have more than doubled. In 2000, methane emissions were estimated to account for 16 percent of all GHG emissions globally, with about 60 percent of total methane emissions coming from anthropogenic (human-induced) sources.
GLOBAL EMISSIONS PROJECTIONS
GLOBAL METHANE EMISSIONS BY SECTOR Global anthropogenic methane emissions for 2005 were estimated at 6,407 million metric tons of CO2 equivalent (MMTCO2E).1 Approximately 40 percent of these emissions come from the four sources targeted by the Methane to Markets Partnership: agriculture (animal waste management), coal mines, landﬁlls, and oil and natural gas systems (see Figure 1).
Partner countries' major methane emission sources and associate project opportunities vary greatly, and thus the opportunities for methane capture and use in each country also vary.
Global anthropogenic methane emissions are projected to increase by 23 percent to 7,904 MMTCO2E by 2020 (see Figure 2).
Figure 2: Estimated and Projected Global Anthropogenic Methane Emissions by Source, 2005 and 2020 2500
Estimated 2005 Emissions
Projected Added Emissions by 2020
Figure 1: Estimated Global Anthropogenic Methane Emissions by Source, 2005
Wastewater 500 0
Biomass Combustion (3%)
Waste water (9%)
Other Agriculture (7%)
Landfills (12%) Oil & Gas (18%)
Coal Mining Biomass
Enteric Fermentation (30%)
Fuel stationary & mobile (1%)
Oil & Gas
Other Agriculture Sources
Stationary and Mobile Sources
From 2005 to 2020, the relative contributions of the agriculture, coal mining, and landﬁll sectors are projected to remain relatively constant, changing by 2 percent or less of global anthropogenic methane emissions or approximately 12 to 16 percent within each sector (see Figure 3 on page 2). Oil and gas emissions, however, are expected to increase by nearly 57 percent from 2005 to 2020, and will account for 5 percent more of the projected global anthropogenic methane emissions annually.
1 Unless otherwise noted, all data from U.S. EPA's Global Anthropogenic Emissions of Non-CO Greenhouse Gases: 1990–2020 (EPA Report 430-R-06-003), 2
Recycled/Recyclable—Printed with vegetable oil based inks on 100% postconsumer, process chlorine free recycled paper.
OVERVIEW OF MITIGATION OPPORTUNITIES
Figure 3: Global Methane Emissions by Sector
Many of the currently available methane mitigation opportunities currently available involve the recovery and use of the methane as fuel for electricity generation, onsite uses, or offsite gas sales. Speciﬁc technologies and mitigation approaches, however, vary by emission source due to their different characteristics and emission processes. The matrix (right) provides a brief summary of the mitigation opportunities by sector compiled from published literature and the work of the Partnership's technical subcommittees, as well as examples of mitigation technologies from Partner Countries.2
Methane to Markets: Advancing Methane Capture and Use Projects
Oil & Gas
BENEFITS OF METHANE MITIGATION Reducing methane emissions has many important energy, economic, environmental, and safety beneﬁts. First, given methane’s short atmospheric lifetime yet global warming potential, methane mitigation is an effective means to reduce climate warming on a relatively short time scale. Methane is also the primary constituent of natural gas. Thus, the collection and utilization of methane provides a valuable, clean-burning and—in the case of agriculture waste management and landﬁlls—renewable energy source that improves the quality of life in local communities and can have the added beneﬁt of generating revenue. Producing energy from recovered methane can also help to avoid the use of higher CO2- and pollutant-emitting energy resources such as wood, coal, and oil. In addition, capturing methane from coal mines can also improve safety conditions by reducing explosion hazards.
The goal of the Methane to Markets Partnership is to identify and develop projects that take advantage of cost-effective mitigation opportunities for methane capture and use. National governments—along with the private sector, development banks, and other interested organizations in the Partnership’s Project Network—are collaborating through Methane to Markets to bring projects to fruition and to achieve the associated climate, economic, and public health beneﬁts. In addition, developed country Partners assist developing countries and countries with economies in transition in recognizing opportunities and expanding methane recovery and use projects through cooperative technical assistance and technology deployment. Please visit the Methane to Markets Project Database at www.methanetomarkets.org/projects to view ongoing Partnership projects and activities, or to suggest a new project or idea.
United States of America
Republic of Korea (South Korea)
2 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.
Sources of Methane
Oil & Gas Systems Emitted during normal operations, routine maintenance, and system disruptions in the oil and natural gas industry.
Total Global Methane Emissions per Sector 1,165.03 MMTCO2E
• Technologies or equipment upgrades that reduce or eliminate 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.methanetomarkets. org/oil-gas
Landﬁlls Produced through the decomposition of organic waste under anaerobic conditions typically found in landﬁlls and large dump sites.
Leak Detection Equipment (Mexico)
• Extraction using a series of wells and a vacuum system, which directs the collected gas to a point to be utilized (e.g., electricity generation, direct use). For more information from the Landﬁlls Subcommittee: www.methanetomarkets. org/landﬁlls Landﬁll Gas Well (China)
Coal Mines Emitted from active and abandoned under-ground mines and surface mines, and as a result of post-mining activities including coal processing, storage, and transportation.
• Degasiﬁcation, where holes are drilled and the methane is captured (not vented) in conjunction with mining operations. • Ventilation air methane (VAM) abatement, where low concentrations of methane are oxidized to generate heat for process use and/or electricity generation. For more information from the Coal Mines Subcommittee: www.methanetomarkets. org/coalmines
Agriculture (Manure Management) Produced from decomposition of livestock and poultry manure stored or treated in systems that promote anaerobic conditions (e.g., liquid or slurry in lagoons, ponds, tanks, or pits).
• Covered anaerobic lagoons collect and transmit lagoon-generated biogas to a dedicated point for transmission to some type of gas use device (e.g., engine). • Digesters (e.g., plug ﬂow, complete mix) that compost or “digest” organic waste in the absence of oxygen, thereby generating methane for collection and use. For more information from the Agriculture Subcommittee: www.methanetomarkets.org/ag
Degasiﬁcation Pump Station (Ukraine)
Floating Dome Anaerobic Digester (India)
EMISSION REDUCTION POTENTIAL BY SECTOR Methane can be relatively inexpensive to reduce compared to CO2 and various government agencies and organizations are incorporating non-CO2 mitigation into analysis and policy discussions. The Global Mitigation of Non-CO2 Greenhouse Gas Report conducted an analysis applying currently available mitigation options and technologies to global methane emission baselines in each target sector to provide insight into methane emission reduction potential and costs.3 Table 1: Global Percentage Reduction From Projected Baseline, 2020 Cost per MTCO2E
13% 21% 30% 34% 36%
15% 80% 80% 80% 80%
12% 41% 50% 57% 88%
Oil & Gas
10% 25% 33% 38% 54%
Source: Global Mitigation of Non-CO2 Greenhouse Gases: 1990–2020 (EPA Report 430-R-06-005)
The Methane to Markets Partnership identiﬁed the following sectors because of their tremendous potentials for reductions in emissions, particularly for those resulting from cost-effective or low-cost actions: •
Agriculture: This sector has the greatest reduction potential because more than 70 percent of the overall potential reductions are low-cost (e.g., $0 to $30/MTCO2E). In this sector, activities costing more ($45 to $60/MTCO2E) do not generate signiﬁcant additional reduction beneﬁts (i.e., less than 4 percent per cost increment).
Coal Mining: More than 65 percent of potential reductions in this sector could be achieved by increasing costs from $0 to $15/MTCO2E, above which the potential for reductions remains steady regardless of increased cost of the activity.
Landﬁlls: This sector has signiﬁcant emission reduction potential of nearly 30 percent change with a minimal $15/ MTCO2E investment, but then the potential reduction drops to less than 10 percent per cost increment if the cost increases from $15 to $45/MTCO2E. In this sector, however, another 30 percent increase in reduction potential exists for activities costing $45 to $60/MTCO2E, which results in a total overall reduction potential for actions from $0 to $60/MTCO2E reaching 76 percent over the baseline, representing the greatest total reduction potential of all sectors.
approximately 15 percent resulting from both the lower (from $0 to $15/MTCO2E) and higher (from $45 to $60/MTCO2E) cost ranges and less than a 10 percent change per cost increment from $15 to $30/MTCO2E and $30 to $45/MTCO2E.
Overall, the potential for methane mitigation at or below $0/ MTCO2E is approximately 500 MMTCO2E, and the mitigation potential more than triples to 1,800 MMTCO2E as the price of the action rises from $0 to $30/MTCO2E. The analyses also found that the largest methane emitters (e.g., China, India, United States) show signiﬁcant mitigation potential in the lower cost range (e.g., $10/MTCO2E).
CONCLUSION There are many cost-effective and economically viable opportunities worldwide to reduce methane emissions. The Methane to Markets Partnership serves as an innovative mechanism to bring together interested parties from government and the private sector to overcome barriers and facilitate methane project development and implementation around the world. By conducting technology transfer, improving local capacity, and marketing project opportunities across borders and sectors, the Partnership is developing local, clean energy resources while reducing GHG emissions.
For additional information, please visit the Methane to Markets Partnership Web site at www.methanetomarkets.org or contact the Administrative Support Group. Administrative Support Group (ASG) Methane to Markets Partnership Tel: +1-202-343-9683 Fax:+1-202-343-2202 E-mail: ASG@methanetomarkets.org
Oil and Gas: Emission reduction potential follows a similar trend as Landﬁlls, with its largest reduction potential of
3 Complete details on the inputs and methodologies used in this analysis are fully described in the report Global Mitigation of Non-CO Greenhouse Gases at 2
Printing was provided by the U.S. Environmental Protection Agency in its capacity as the Administrative Support Group for the Methane to Markets Partnership.