A Community Emissions Data System (CEDS) for Historical Emissions

A data-driven, open source framework of historical emission estimates for Earth system models, climate models, atmospheric chemistry and transport models, and integrated assessment models.

Soot on a bus

Emissions data is a necessary component of Earth system models, climate models, atmospheric chemistry and transport models, and integrated assessment models

Photo by D. Ryabov

Historical emission estimates for anthropogenic aerosol and precursor compounds are key data needed for Earth system, climate, atmospheric chemistry, and transport models, as well as for economic and energy models. Historical emissions data are used both for general analysis and assessment and also for model validation through comparisons with observations. The core CEDS project is funded by the US Department of Earth and Environmental System Modeling (EESM) Program. Sub-regional detail and use of satellite datasets is funded by NASA’s Atmospheric Composition Modeling and Analysis Program (ACMAP).

Project Goals

The CEDS project has built a data-driven, open source framework that produces global emission estimates for research and analysis. The data system produces emission estimates by country, sector, and fuel with the following characteristics:

  • Annual estimates of anthropogenic emissions (not including open burning) to latest full calendar year over the entire industrial era, updated every year
  • Emission species: aerosol (BC, OC) and aerosol precursor and reactive compounds (SO2, NOx, NH3, CH4, CO, NMVOC) CO2, and N2O
  • Gridded emissions (0.5° and 0.1° for recent decades)
  • Seasonal cycle (monthly) and speciated NMVOCs by sector
  • State/province spatial detail for large countries – in progress

CEDS gitHub Site

The CEDS public gitHub repository contains the latest public release of R code, input files, documentation, issues tracking, and links to the latest data.

    Project Status

    • An update of the emissions time series out to 2021 is in progress
    • Gridded emissions over 1980-2019 for V_2021_04_21 downscaled to 0.1 degrees are now available.
    • Updated historical emissions over 1750-2019, along with the underlying data system, have been released (V_2021_04_21). This includes both aggregate emissions (by country/sector and country/fuel) and gridded emissions.
    • Historical gridded emissions data from CEDS were used in the Coupled Model Inter-comparison Project Phase 6 (CMIP6) and is available through the Earth System Grid Federation. More details are available on CEDS CMIP6 page. Journal articles describing the data and methodology and the gridded data have been published in the CMIP6 special issue of Geoscientific Model Development, with the most up-to-date documentation available at the project gitHub site.
    • An update focusing on recent decades out to 2017 was released by McDuffie et al. (2020).
    • Uncertainty estimates are being produced as time series ensembles.
    • In collaboration with scientists at GSFC, we are adding additional sectoral detail and incorporating satellite emission estimates.

    Community Input

    We welcome collaboration in improving the inventory data. Our collaboration policy is described on our gitHub repository home page.

    CEDS e-mail list

    To receive updates on project progress and notice of opportunities for participation you can sign up for an information distribution list. (This list will be used only for CEDS-related information and e-mail addresses will not be shared or distributed.) To subscribe to the listserv, please send an email with the email body: “subscribe cedsinfo”. Visit the listserv. You do not have to be registered to view the archive on the website.

    Issues at the gitHub repository

    Known issues with the current CEDS data (both aggregate and gridded) are documented at the gitHub repository. If you find an issue with the current CEDS data, please post an issue using the “Issues” tab of the repository so that that information is publicly available and can be addressed.

    Related Research

    Also see the Emissions-MIP page for information on this related project, which aims to determine which aspects of aerosol and precursor emissions impact model results.

    Journal Articles

    Hoesly, R. M., Smith, S. J., Feng, L., Klimont, Z., Janssens-Maenhout, G., Pitkanen, T., Seibert, J. J., Vu, L., Andres, R. J., Bolt, R. M., Bond, T. C., Dawidowski, L., Kholod, N., Kurokawa, J.-I., Li, M., Liu, L., Lu, Z., Moura, M. C. P., O’Rourke, P. R., and Zhang, Q.: Historical (1750–2014) anthropogenic emissions of reactive gases and aerosols from the Community Emissions Data System (CEDS), Geosci. Model Dev., 11, 369-408,, 2018.
    (See CEDS CMIP6 details on data availability.)

    Hoesly R.M. and S.J. Smith. 2018. “Informing energy consumption uncertainty: an analysis of energy data revisions.” Environ. Res. Lett. 13 124023.

    Feng, L., Smith, S. J., Braun, C., Crippa, M., Gidden, M. J., Hoesly, R., Klimont, Z., van Marle, M., van den Berg, M., and van der Werf, G. R.: The Generation of Gridded Emissions Data for CMIP6 (2020)  Geosci. Model Dev., 13, 461–482, .

    Related Work

    Smith, S. J., McDuffie, E. E., and Charles, M.: Opinion: Coordinated development of emission inventories for climate forcers and air pollutants, Atmos. Chem. Phys., 22, 13201–13218, .