Global geological methane emissions
An update of top-down and bottom-up estimates
Bibliographic Data
| ID | 19568757 |
|---|---|
| Authors | Giuseppe Etiope (0000-0001-8614-4221, Istituto Nazionale di Geofisica e Vulcanologia), Stefan Schwietzke (0000-0002-1836-8968, 2Environmental Defense Fund, London, UK) |
| Editors | Detlev Helmig (0000-0003-1612-1651), Paul Palmer |
| Year | 2019 |
| Volume | 7 |
| Publication date | 2019-01-01 |
| Peer Reviewed | Yes |
| Open Access | Yes |
| Type | ARTICLE |
| Venue | Elementa Science of the Anthropocene (JOURNAL) |
| Journal identifiers | ISSN: 2325-1026 • E-ISSN: 2325-1026 |
| Publisher | University of California Press (PUBLISHER • US) |
| DOI | 10.1525/elementa.383 |
| OpenAlex | W2989978033 |
| Language | EN |
| Citations received | 4 |
| References cited | 34 |
A wide body of literature suggests that geological gas emissions from Earth’s degassing are a major methane (CH4) source to the atmosphere. These emissions are from gas-oil seeps, mud volcanoes, microseepage and submarine seepage in sedimentary (petroleum-bearing) basins, and geothermal and volcanic manifestations. Global bottom-up emission estimates, ranging from 30 to 76 Tg CH4 yr–1, evolved in the last twenty years thanks to the increasing number of flux measurements, and improved knowledge of emission factors and area distribution (activity). Based on recent global grid maps and updated evaluations of mud volcano and microseepage emissions, the global geo-CH4 source is now (bottom-up) estimated to be 45 (27–63) Tg yr–1, i.e., ~8% of total CH4 sources. Top-down verifications, based on independent approaches (including ethane and isotopic observations) from different authors, are consistent with the range of the bottom-up estimate. However, a recent top-down study, based on radiocarbon analyses in polar ice cores, suggests that geological, fossil (14C-free) CH4 emissions about 11,600 years ago were much lower (<15 Tg yr–1, 95% CI) and that this source strength could also be valid today. Here, we show that (i) this geo-CH4 downward revision implies a fossil fuel industry CH4 upward revision of at least 24–35%. (ii) The 95% CI estimates of the recent radiocarbon analysis do not overlap with those of 5 out of 6 other bottom-up and top-down studies (no overlap for the 90% CI estimates). (iii) The contrasting lines of evidence require further discussion, and research opportunities exist to help explain this gap
Atmospheric sciences · Earth science · Fossil fuel · Geochemistry · Geothermal gradient · Greenhouse gas · Methane · Radiocarbon dating · Sedimentary rock · Volcano · Atmospheric and Environmental Gas Dynamics · Environmental Science · Hydrocarbon exploration and reservoir analysis · Methane Hydrates and Related Phenomena · Geology · Oceanography · Paleontology
| Unique citing works | 4 |
|---|---|
| Citations per year | 0.67 |
| Citation span | 2020 - 2024 (5) |
| Citation velocity | recent |
| Highly cited | No |
| Citation types | Neutral: 4 |