A Caltech Library Service

California’s methane super-emitters

Duren, Riley M. and Thorpe, Andrew K. and Foster, Kelsey T. and Rafiq, Talha and Hopkins, Francesca M. and Yadav, Vineet and Bue, Brian D. and Thompson, David R. and Conley, Stephen and Colombi, Nadia K. and Frankenberg, Christian and McCubbin, Ian B. and Eastwood, Michael L. and Falk, Matthias and Herner, Jorn D. and Croes, Bart E. and Green, Robert O. and Miller, Charles E. (2019) California’s methane super-emitters. Nature, 575 (7781). pp. 180-184. ISSN 0028-0836. doi:10.1038/s41586-019-1720-3.

[img] PDF (Materials and Methods, Supplementary Figs 1–14, Supplementary Tables 1–3, descriptions of Supplementary Tables 4 and 5, and additional references) - Supplemental Material
See Usage Policy.

[img] PDF (Supplementary Table 4 - Methane plume list) - Supplemental Material
See Usage Policy.

[img] PDF (Supplementary Table 5 - Methane source list) - Supplemental Material
See Usage Policy.


Use this Persistent URL to link to this item:


Methane is a powerful greenhouse gas and is targeted for emissions mitigation by the US state of California and other jurisdictions worldwide. Unique opportunities for mitigation are presented by point-source emitters—surface features or infrastructure components that are typically less than 10 metres in diameter and emit plumes of highly concentrated methane. However, data on point-source emissions are sparse and typically lack sufficient spatial and temporal resolution to guide their mitigation and to accurately assess their magnitude4. Here we survey more than 272,000 infrastructure elements in California using an airborne imaging spectrometer that can rapidly map methane plumes. We conduct five campaigns over several months from 2016 to 2018, spanning the oil and gas, manure-management and waste-management sectors, resulting in the detection, geolocation and quantification of emissions from 564 strong methane point sources. Our remote sensing approach enables the rapid and repeated assessment of large areas at high spatial resolution for a poorly characterized population of methane emitters that often appear intermittently and stochastically. We estimate net methane point-source emissions in California to be 0.618 teragrams per year (95 per cent confidence interval 0.523–0.725), equivalent to 34–46 per cent of the state’s methane inventory for 2016. Methane ‘super-emitter’ activity occurs in every sector surveyed, with 10 per cent of point sources contributing roughly 60 per cent of point-source emissions—consistent with a study of the US Four Corners region that had a different sectoral mix. The largest methane emitters in California are a subset of landfills, which exhibit persistent anomalous activity. Methane point-source emissions in California are dominated by landfills (41 per cent), followed by dairies (26 per cent) and the oil and gas sector (26 per cent). Our data have enabled the identification of the 0.2 per cent of California’s infrastructure that is responsible for these emissions. Sharing these data with collaborating infrastructure operators has led to the mitigation of anomalous methane-emission activity.

Item Type:Article
Related URLs:
URLURL TypeDescription ReadCube access
Duren, Riley M.0000-0003-4723-5280
Thorpe, Andrew K.0000-0001-7968-5433
Hopkins, Francesca M.0000-0002-6110-7675
Yadav, Vineet0000-0002-2805-3345
Bue, Brian D.0000-0002-7856-3570
Thompson, David R.0000-0003-1100-7550
Frankenberg, Christian0000-0002-0546-5857
Eastwood, Michael L.0000-0002-4731-6083
Falk, Matthias0000-0002-8901-2838
Miller, Charles E.0000-0002-9380-4838
Additional Information:© 2019 Springer Nature Limited. Received 05 December 2018; Accepted 20 August 2019; Published 06 November 2019. Data availability: Radiance and reflectance products calibrated by AVIRIS-NG can be ordered from the AVIRIS-NG data portal at Retrieved methane images from flight lines in this study are available for download at Vista-CA infrastructure spatial layers are available for download at Images of methane plumes, Vista-CA layers and regional-scale methane-emission products for California can be viewed at Tables of methane plume and source characteristics are provided in the Supplementary Information. Code availability: The custom computer code or algorithms used to generate the results in this study can be made available to researchers upon request. We thank the AVIRIS-NG team and Dynamic Aviation for their efforts in conducting the multiple airborne campaigns involved in this study, and our former colleague at the Jet Propulsion Laboratory (JPL), A. Aubrey, for early support in project planning. We acknowledge G. Franco (California Energy Commission, CEC) and E. Tseng (University of California Los Angeles) for comments on the paper. We appreciate the many discussions and input to flight planning and analysis from our colleagues at the California Air Resources Board (CARB), the Bay Area Air Quality Management District, the South Coast Air Quality Management District, the CEC, Southern California Gas Company, Sunshine Canyon Landfill Local Enforcement Agency, and the Milk Producer’s Council. We thank our colleagues at the Pacific Gas and Electric Company for their support for natural gas control release tests. We thank NASA’s Earth Science Division, particularly J. Kaye, for continued support of AVIRIS-NG methane science. Additional funding for data collection and analysis was provided to JPL by CARB under ARB-NASA Agreement 15RD028 Space Act Agreement 82-19863 and the CEC under CEC-500-15-004. The data from follow-up and contemporaneous Scientific Aviation flights used in this study were funded by CARB. Analysis of this work was also supported in part by NASA’s Carbon Monitoring System (CMS) Prototype Methane Monitoring System for California and the Advancing Collaborative Connections for Earth System Science (ACCESS) Methane Source Finder project. A portion of this research was carried out at the JPL, California Institute of Technology, under contract with NASA (NNN12AA01C). The authors are responsible for the content of the paper and the findings do not represent the views of the funding agencies. Author Contributions: R.M.D., A.K.T., F.M.H. and C.E.M conceived the study. R.M.D., A.K.T., F.M.H., T.R., I.B.M., M.L.E. and S.C. conducted flight planning. Each author contributed to the collection, analysis or assessment of one or more datasets necessary to perform this study. R.M.D., A.K.T., K.T.F., F.M.H. and T.R performed the analysis with contributions from B.D.B., D.R.T., C.F., N.K.C., M.F., J.D.H, B.E.C., R.O.G. and V.Y. R.M.D., A.K.T., K.T.F. and F.M.H. wrote the manuscript with input from all authors. The authors declare no competing interests.
Funding AgencyGrant Number
California Air Resources Board15RD028
California Energy CommissionCEC-500-15-004
Subject Keywords:Atmospheric science; Carbon cycle
Issue or Number:7781
Record Number:CaltechAUTHORS:20190802-124838747
Persistent URL:
Official Citation:Duren, R.M., Thorpe, A.K., Foster, K.T. et al. California’s methane super-emitters. Nature 575, 180–184 (2019) doi:10.1038/s41586-019-1720-3
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:97620
Deposited By: George Porter
Deposited On:06 Nov 2019 19:11
Last Modified:16 Nov 2021 17:33

Repository Staff Only: item control page