Natural gas is mostly methane (CH4), a powerful greenhouse gas that traps more radiation than carbon dioxide (CO2) and contributes to the formation of ground-level ozone, a dangerous air pollutant.1,2Â In the United States, the Environmental Protection Agency (EPA) is proposing methane limits for new and existing oil and gas infrastructure, and restricting intentional releases of methane at oil and natural gas facilities.
Methane is often intentionally released from oil and gas wells through venting or flaring natural gas. Methane emissions occur during all phases of drilling and production, and sometimes after a well has ceased production – improperly plugged wells can emit large volumes of methane and other hazardous air pollution.
Methane levels in the air are now higher than at any point in in human history, driven by emissions from the fossil fuel and agriculture/livestock sectors.3 Since methane lasts for less than a decade in the atmosphere, reducing methane emissions will have a rapid and significant effect on the rate of climate change.3,4
New and improved, readily available technologies offer ways to reduce or eliminate venting and flaring of natural gas, and better manage methane. Reductions in waste gas emissions from oil and gas production are possible using technologies such as gas injection and on-site power generation. Most measures could be implemented at negative or low cost.4
New sensors and monitoring technologies allow increasingly high-precision measurements of methane emissions from plane-mounted sensors and satellites. Utilities, oil and gas companies, regulators, researchers, and others are creating and deploying sensor systems and methane detectors across a range of areas and facilities.
Recent scientific research suggests that the volume of methane released from oil and gas production, processing, and transportation activities across the United States has been significantly underestimated.5,6,7,8 Current regulations differ by state and very few states have standards for existing sources. Transparent and independently verifiable emissions data and mitigation analyses is needed. Effectively managing methane emissions requires more accurate monitoring and emissions estimates. Improved methane monitoring and assessment will speed strategic decision making and innovation to reduce methane emissions.
Scientific evidence detailing how best to measure, monitor, and mitigate methane emissions from the oil and gas industry will play an important role in setting appropriate and protective limits to protect health and meet U.S. climate goals.
ADDITIONAL RESOURCES
American Geosciences Institute: Mitigating and Regulating Methane Emissions
Environmental Protection Agency:Â Overview of Greenhouse Gases-Â Methane
Environmental Protection Agency:Â Inventory of U.S. Greenhouse Gas Emissions and Sinks
Environmental Protection Agency:Â Voluntary Methane Programs for the Oil and Natural Gas Industry
Rice University’s Baker Institute for Public Policy: Reducing Oilfield Methane Emissions Can Create New US Gas Export Opportunities
United Nations Environment Program: Global Methane Assessment: Benefits and Costs of Mitigating Methane Emissions
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Last updated November 1, 2021
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References
1. “Overview of Greenhouse Gases,” Environmental Protection Agency. [Online]. Available: https://www.epa.gov/ghgemissions/overview-greenhouse-gases#methane
2. “Inventory of U.S. Greenhouse Gas Emissions and Sinks 1990-2018: Abandoned Oil and Gas Wells,” Environmental Protection Agency, 2020 [Online]. Available: https://www.epa.gov/sites/production/files/2020-04/documents/us-ghg-inventory-2020-main-text.pdf
3. “AR6 Climate Change 2021: The Physical Science Basis” International Panel on Climate Change, 2021 [Online]. Available: https://www.ipcc.ch/report/ar6/wg1/
4. “Global Methane Assessment: Benefits and Costs of Mitigating Methane Emissions” United Nations Environment Program, 2021 [Online]. Available: https://www.unep.org/resources/report/global-methane-assessment-benefits-and-costs-mitigating-methane-emissions
5. Zhang Y. et al, “Quantifying methane emissions from the largest oil-producing basin in the United States from space,” Science Advances, vol. 6, no. 17, 2020.
6. “Major studies reveal 60% more methane emissions,” Environmental Defense Fund. [Online]. Available: https://www.edf.org/climate/methane-studies
7. Alvarez R. A. et al, “Assessment of methane emissions from the U.S. oil and gas supply chain,” Science, vol. 361, no. 6398, pp. 186-188, 2018.
8. Williams et al, “Methane Emissions from Abandoned Oil and Gas Wells in Canada and the United States,” Environmental Science and Technology, 2021, 55, 1, 563–570 Available: https://pubs.acs.org/doi/pdf/10.1021/acs.est.0c0426
