Gridded EPA U.S. Anthropogenic Methane Greenhouse Gas Inventory (gridded GHGI)
Year: 2023
Type: dataset
Abstract: **** THE FOLLOWING DATA HAVE NOT BEEN PEER-REVIEWED **** *** This repository will be updated upon peer-review and final publication of the associated manuscript. *** About The gridded EPA U.S. anthropogenic methane greenhouse gas inventory (gridded GHGI) includes spatially and temporally resolved (gridded) maps of annual anthropogenic methane emissions (0.1°×0.1°) for the contiguous United States (CONUS). Total gridded methane emissions for each source sector are consistent with national annual U.S. anthropogenic methane emissions reported in the U.S. EPA Inventory of U.S. Greenhouse Gas Emissions and Sinks (U.S. GHGI). This repository accompanies the preprint manuscript Maasakkers, et al., 2023, which has been submitted as a non peer-reviewed preprint to EarthArXiv. This repository is an update to the gridded GHGI version 1, previously described in Maasakkers, et al., (2016) and currently available on the U.S. EPA website. The EPA website will be updated with version 2 of the gridded GHGI upon review and final publication of the manuscript. This repository contains two datasets: Gridded GHGI Data (main dataset; 2 file types). Gridded annual U.S. anthropogenic methane emissions for 2012-2018 for 26 source categories, hereafter called the gridded GHGI. This dataset is developed to be consistent with the national U.S. GHGI published in 2020 (U.S. EPA , Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990 - 2020. U.S. Environmental Protection Agency, 2020, EPA 430-R-22-003, https://www.epa.gov/ghgemissions/inventory-us-greenhouse-gas-emissions-and-sinks-1990-2018) (hereafter called the U.S. GHGI). This gridded dataset represents an update to the original version 1 of the gridded GHGI from Maasakkers, et al., (2016). The annual files contain one year of emissions per source category but include a time dimension to make them suitable (COARDS-compliant) for atmospheric models. This main dataset also includes monthly source-specific methane emission scaling factors for those select sources with strong interannual variability. a. Annual emission flux files containing individual variables for the 26 different source categories. (dimensions: time x lat x lon; units: molec. CH4 cm-2 s-1): - Gridded_GHGI_Methane_v2_YYYY.nc b. Monthly scaling factor files containing individual variables for the different source categories that have strong interannual variability. These scaling factors can be multiplied with the data in the annual emission files to get monthly methane emission fluxes for these select source categories. (dimensions: time x lat x lon; units: dimensionless): - Gridded_GHGI_Methane_v2_Monthly_Scale_Factors_YYYY.nc Gridded GHGI Express Extension (1 file type). Gridded annual U.S. anthropogenic methane emissions for 2012-2020 for 27 source categories (one additional source category compared to the main dataset above), hereafter called the express extension. This dataset is developed for total methane emissions to be consistent with the U.S. GHGI published in 2022 (EPA (2022) Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2020. U.S. Environmental Protection Agency, EPA 430-R-22-003. https://www.epa.gov/ghgemissions/draft-inventory-us-greenhouse-gas-emissionsand-sinks-1990-2020). This dataset is *not* a full update to the main gridded GHGI dataset, and instead uses annual source-specific spatial patterns from 2012-2018 from the main dataset to quickly incorporate more recent national methane emission estimates. Emissions for years after 2018 follow the 2018 spatial patterns. a. Annual emission files (dimensions: time x lat x lon; units: molec. CH4 cm-2 s-1): - Express_Extension_Gridded_GHGI_Methane_v2_YYYY.nc ---- Data Details: Annual gridded emissions files for both datasets (main gridded dataset and the express extension) include annual methane emission fluxes from the following sources: Sources listed by name and IPCC/UNFCCC common reporting format (CRF) table categories. Agriculture Enteric Fermentation (3A) Manure Management* (3B) Rice Cultivation* (3C) Field Burning of Agricultural Residues* (3F) Natural Gas Systems Exploration* (1B2b) Production* (1B2b) Transmission & Storage (1B2b) Processing (1B2b) Distribution (1B2b) Post-Meter (1B2b) (2022 express extension only) Petroleum Systems Exploration* (1B2a) Production* (1B2a) Transport* (1B2a) Refining* (1B2a) Waste Municipal Solid Waste (MSW) Landfills (5A1) Industrial Landfills (5A1) Domestic Wastewater Treatment & Discharge (5D) Industrial Wastewater Treatment & Discharge (5D) Composting (5B1) Coal Mines Underground Coal Mining (1B1a) Surface Coal Mining (1B1a) Abandoned Underground Coal Mines (1B1a) Other Stationary combustion* (1A) Mobile Combustion (1A) Abandoned Oil and Gas Wells (1B2a & 1B2b) Petrochemical Production (2B8) Ferroalloy Production (2C2) Additional Notes: ‘Grid_cell_area’ (dimensions: time x lat x lon, units: cm2) - this variable is included to help users convert the emission fluxes to emission mass totals. This variable includes a time dimension to make it suitable (COARDS-compliant) for atmospheric models. Monthly scale factors: Scale factors for the main dataset are published in a separate file for all sources listed above with an '*'. For the express extension, we recommend using the relative source-specific scale factors for years 2012-2018. Year 2018 scale factors can be used for manure management, rice cultivation, and field burning of agricultural residue emissions only. For other sources, monthly variability is too year-specific and should not be extrapolated to the express extension dataset for years after 2018. The gridded GHGI does not currently include emissions from the Land Use, Land Use Change, and Forestry (LULUCF) category of the national U.S. GHGI. Methane emissions from these sources include but are not limited to emissions from fires and flooded lands. Both datasets (main gridded dataset and express extension) were produced using source specific Jupyter Notebooks, which will be made available upon publication of the manuscript. ---- Frequently Asked Questions (FAQs): Q: How do both datasets (main gridded GHGI and express extension) relate to the U.S. National GHG Inventory (Inventory of U.S. Greenhouse Gas Emissions and Sinks)? A: EPA develops an annual report, called the Inventory of U.S. Greenhouse Gas Emissions and Sinks (GHGI), that tracks U.S. greenhouse gas emissions and sinks by source, economic sector, and greenhouse gas going back to 1990 (called here the U.S. GHGI). The U.S. GHGI provides a comprehensive accounting of total greenhouse gas emissions for all human-made sources in the United States, including carbon dioxide removal from the atmosphere by “sinks,” (e.g., through the uptake of carbon and storage in forests, vegetation, and soils) from management of lands in their current use or as lands are converted to other uses. EPA has prepared the U.S. GHGI since the early 1990s and submits the report annually to the United Nations in accordance with the UN Framework Convention on Climate Change (UNFCCC). The emissions and removals in the U.S. GHGI are calculated using internationally accepted methods provided by the IPCC in the 2006 IPCC Guidelines for National Greenhouse Gas Inventories (2006 IPCC Guidelines) and where appropriate, its supplements and refinements. Data are reported in a common format, in line with the UNFCCC reporting guidelines. The U.S. GHGI is separate product to the EPA National Emissions Inventory (NEI). The gridded GHGI (main gridded dataset) was developed as a spatial representation of source-specific methane emissions reported in the 2020 U.S. GHGI (for years 2012-2018). In this product, the sum of gridded methane emissions for each source in each year will equal the total anthropogenic methane emissions from each source reported in the 2020 U.S. GHGI (excluding emissions from Alaska (AK), Hawaii (HI), and U.S. territories, which are not included in the gridded GHGI). As the U.S. GHGI is an annual report, some emission and sink estimates in the U.S. GHGI are recalculated and revised each year by the EPA to incorporate improved methods and/or data. The most common reason for recalculating U.S. greenhouse gas emission estimates is to update recent historical data. Changes in historical data are generally the result of changes in data supplied by other U.S. government agencies or organizations, as they continue to make refinements and improvements. These improvements are implemented consistently across the U.S. GHGI’s time series, as necessary, (i.e., 1990 to 2020) to ensure that the emissions trend is accurate. To reflect these changes, the express extension of the gridded GHGI is developed as an approximate representation of the spatial patterns of source-specific methane emissions reported in the 2022 U.S. GHGI report (for years 2012-2020). The fractional spatial patterns used to grid each source are the same as those derived from the main gridded dataset, but the sum of methane emissions from each source will equal those reported in the 2022 U.S. GHGI (excluding emissions from AK, HI, and U.S. territories, which are not included in the gridded GHGI). Users are directed to the 2020 and 2022 EPA National GHGI Reports for more specific information about major methodological differences between the two national inventory versions. Q: How does the EPA National U.S. GHGI compare to the EP
Language: English
Subfield: Global and Planetary Change
Field: Environmental Science
Domain: Physical Sciences
SDG: Climate action
Open Access status: green
OpenAlex ID: W4393708682