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Paper title Methane emissions from the oil, gas and coal sectors as reported in bottom-up inventories and in atmospheric inversions
Authors
  1. Zitely Tzompa Sosa Laboratoire des Sciences du Climat et de l'Environnement (LSCE) Speaker
  2. Zhu Deng Tsinghua University
  3. Philippe Ciais Laboratoire des Sciences du Climat et de l'Environnement (LSCE)
  4. Marielle Saunois Université Paris-Saclay, CNRS CEA UVSQ, Laboratoire des Sciences du Climat et de l’Environnement (LSCE)
  5. Frédéric Chevallier Laboratoire des Sciences du Climat et de l'Environnement (LSCE)
  6. Chunjing Qiu Nanjing Univeristy
  7. Xin Lin Laboratoire des Sciences du Climat et de l'Environnement (LSCE)
  8. Thomas Lauvaux Laboratoire des Sciences du Climat et de l'Environnement (LSCE)
  9. Alexandre D'Aspremont Kayrros
  10. Clément Giron Kayrros
  11. Antoine Benoit Kayrros
Form of presentation Poster
Topics
  • A1. Atmosphere
    • A1.04 Greenhouse Gases
Abstract text Globally, the oil, gas and coal sectors are the main emitters of anthropogenic methane (CH4) from fossil fuel sources. Together, these sectors represent one third of total global anthropogenic CH4 emissions. Despite a reduction in some basins due to the COVID-19 pandemic, global emissions from the oil and gas sector have rapidly increased over the last decades. This study presents results of global atmospheric inversions and compares them to national reports and other emission inventories. Results show that inversions tend to estimate higher CH4 emissions compared to national reports of oil-and-gas-producing countries like Russia, Kazakhstan, Turkmenistan and those located in the Arabic Peninsula. This difference might be partially explained since ultra-emitting events, consisting of large and sporadic emissions (greater than ≈ 20 tCH4 per hour), are not considered by emission inventories. Ultra-emitters are especially important in some countries, such as Kazakhstan and Turkmenistan, where estimated ultra-emitter emissions are comparable (1.4 Tg yr-1) to total fossil fuel emissions reported in their national inventories (1.5 Tg yr-1) and to half (on average) of the values reported in the other inventories that we analyzed. This study also considers emissions derived from regional inversions using S5P-TROPOMI atmospheric measurements at the scale of regional extraction basins for oil, gas and coal. Here, we assumed that those basins are already counted as part of the national CH4 budgets from in-situ-driven and GOSAT-driven inversions. Two coal basins, one in the USA and one in Australia, were considered. Also, six major oil and gas basins (3 in the USA, 2 in the Arabian Peninsula, and 1 in Iran) were considered as specific areas where many individual wells and storage facilities are concentrated. Averaged emissions (2019-2020) from the Bowen basin in Australia are greater than 2017 emissions estimated by inversions. For the USA, emissions from all basins analyzed, account for ~60% of total USA fossil fuel emissions estimated by inversions. For oil and gas, a basin encompassing four of the highest oil-producing fields in the world (comprising Iraq and Kuwait) represents ~38% of the total fossil emissions estimated by inversions for the Arabian Peninsula. Lastly, the basin estimation for Iran (2.5 TgCH4) represents ~68% of fossil fuel emissions from inversions and ~59% of independent inventories. Given the important role of the oil, gas and coal sectors to global anthropogenic emissions of CH4, our synthesis allows interpreting the main apparent differences between a large suite of recent emission estimates for these sectors.