Improving Characterization of Anthropogenic Methane Emissions in the United States

Understanding, quantifying, and tracking atmospheric methane and emissions is essential for addressing concerns and informing decisions that affect the climate, economy, and human health and safety. Atmospheric methane is a potent greenhouse gas (GHG) that contributes to global warming. While carbon dioxide is by far the dominant cause of the rise in global average temperatures, methane also plays a significant role because it absorbs more energy per unit mass than carbon dioxide does, giving it a disproportionately large effect on global radiative forcing. In addition to contributing to climate change, methane also affects human health as a precursor to ozone pollution in the lower atmosphere. Improving Characterization of Anthropogenic Methane Emissions in the United States summarizes the current state of understanding of methane emissions sources and the measurement approaches and evaluates opportunities for methodological and inventory development improvements. This report will inform future research agendas of various U.S. agencies, including NOAA, the EPA, the DOE, NASA, the U.S. Department of Agriculture (USDA), and the National Science Foundation (NSF). Table of ContentsFront MatterSummary1 Introduction2 Current Inventories of Methane Emissions3 Methane Emission Measurement and Monitoring Methods4 Addressing Uncertainties in Anthropogenic Methane Emissions5 Presenting Methane Emission Data and Results6 Meeting the Challenges of Characterizing Methane EmissionsReferencesGlossaryAppendix A: Acronyms and AbbreviationsAppendix B: Definition of U.S. Greenhouse Gas Inventory CategoriesAppendix C: Other Anthropogenic Sources of MethaneAppendix D: U.S. Greenhouse Gas Inventory DevelopmentAppendix E: Acknowledgment of Those Who Provided Input to the CommitteeAppendix F: Common Units for Reporting Methane Concentrations and EmissionsAppendix G: Biographical Sketches of Committee MembersAppendix H: Disclosure of Conflict of Interest