Global Inventory of Gas Geochemistry Data from Fossil Fuel, Microbial and Burning Sources, version 2017

Owen A. Sherwood, Stefan Schwietzke, Victoria A. Arling, Giuseppe Etiope
2017 Earth System Science Data  
<p><strong>Abstract.</strong> The concentration of atmospheric methane (CH<sub>4</sub>) has more than doubled over the industrial era. To help constrain global and regional CH<sub>4</sub> budgets, inverse (top-down) models incorporate data on the concentration and stable carbon (<i>δ</i><sup>13</sup>C) and hydrogen (<i>δ</i><sup>2</sup>H) isotopic ratios of atmospheric CH<sub>4</sub>. These models depend on accurate <i>δ</i><sup>13</sup>C and <i>δ</i><sup>2</sup>H end-member source signatures
more » ... source signatures for each of the main emissions categories. Compared with meticulous measurement and calibration of isotopic CH<sub>4</sub> in the atmosphere, there has been relatively less effort to characterize globally representative isotopic source signatures, particularly for fossil fuel sources. Most global CH<sub>4</sub> budget models have so far relied on outdated source signature values derived from globally nonrepresentative data. To correct this deficiency, we present a comprehensive, globally representative end-member database of the <i>δ</i><sup>13</sup>C and <i>δ</i><sup>2</sup>H of CH<sub>4</sub> from fossil fuel (conventional natural gas, shale gas, and coal), modern microbial (wetlands, rice paddies, ruminants, termites, and landfills and/or waste) and biomass burning sources. Gas molecular compositional data for fossil fuel categories are also included with the database. The database comprises 10<span class="thinspace"></span>706 samples (8734 fossil fuel, 1972 non-fossil) from 190 published references. Mean (unweighted) <i>δ</i><sup>13</sup>C signatures for fossil fuel CH<sub>4</sub> are significantly lighter than values commonly used in CH<sub>4</sub> budget models, thus highlighting potential underestimation of fossil fuel CH<sub>4</sub> emissions in previous CH<sub>4</sub> budget models. This living database will be updated every 2–3 years to provide the atmospheric modeling community with the most complete CH<sub>4</sub> source signature data possible. Database digital object identifier (DOI): <a href="https://doi.org/10.15138/G3201T" target="_blank">https://doi.org/10.15138/G3201T</a>.</p>
doi:10.5194/essd-9-639-2017 fatcat:uzjc2y3wvnb7hisb4r7unwyuqi