The Global Methane Budget is coordinated by the Global Carbon Project (GCP) and published sources and sinks budgets of methane in the atmosphere, which is consistent with the observed atmospheric growth rate when estimated by top-down/inverse modelling. The top-down models refine the bottom-up methane budget, which is based on emission-sector-specific activity data, based on process understanding of emissions of methane.
JAMSTEC scientist, Prabir Patra, contributed to the 2024 release of the Global Methane Budget (Saunois et al., 2024), in particular using inverse modelling, along with colleagues (Dr. Dmitry Belikov) from Chiba University who are collaborating through the SII-8 and S-22 projects of Ministry of the Environment, Japan. Dr. Patra co-leads the top-down modelling component of the global methane budget along with Marielle Saunois of LSCE. He also contributed with new information on the interannual variability of hydroxyl radicals (OH) based on Patra et al. (2021), which react with CH4 and thereby represent about 90% of the methane removal from the atmosphere. These modelling systems of OH interannual variability and methane inversion using MIROC4-ACTM are developed and run using the supercomputing facilities at JAMSTEC, such as the 4th generation Earth Simulator (ES4). Prabir Patra actively contributes to the community methane research as a science steering committee member of the GCP, under Future Earth (Jackson et al., 2024).
Jackson, R. B., M. Saunois, A. Martinez, J. G. Canadell, X. Yu, M. Li, B. Poulter, P. A. Raymond, P. Regnier, P. Ciais, S. J. Davis and P. K. Patra, Human activities now fuel two-thirds of global methane emissions, Environ. Res. Lett., 19, 101002, doi: 10.1088/1748-9326/ad6463, 2024
Patra, P. K., M. C. Krol, R. G. Prinn, M. Takigawa, J. Mühle, S. A. Montzka, S. Lal, Y. Yamashita, S. Naus, N. Chandra, R. F. Weiss, P. Krummel, P. Fraser, S. O'Doherty, J. W. Elkins, Methyl Chloroform continues to constrain the hydroxyl (OH) variability in the troposphere, J. Geophys. Res., 126, e2020JD033862, 2021.
Saunois, M., Martinez, A., Poulter, B., Zhang, Z., Raymond, P., Regnier, P., Canadell, J. G., Jackson, R. B., Patra, P. K., Bousquet, P., Ciais, P., Dlugokencky, E. J., Lan, X., Allen, G. H., Bastviken, D., Beerling, D. J., Belikov, D. A., Blake, D. R., Castaldi, S., Crippa, M., Deemer, B. R., Dennison, F., Etiope, G., Gedney, N., Höglund-Isaksson, L., Holgerson, M. A., Hopcroft, P. O., Hugelius, G., Ito, A., Jain, A. K., Janardanan, R., Johnson, M. S., Kleinen, T., Krummel, P., Lauerwald, R., Li, T., Liu, X., McDonald, K. C., Melton, J. R., Mühle, J., Müller, J., Murguia-Flores, F., Niwa, Y., Noce, S., Pan, S., Parker, R. J., Peng, C., Ramonet, M., Riley, W. J., Rocher-Ros, G., Rosentreter, J. A., Sasakawa, M., Segers, A., Smith, S. J., Stanley, E. H., Thanwerdas, J., Tian, H., Tsuruta, A., Tubiello, F. N., Weber, T. S., van der Werf, G., Worthy, D. E., Xi, Y., Yoshida, Y., Zhang, W., Zheng, B., Zhu, Q., Zhu, Q., and Zhuang, Q.: Global Methane Budget 2000–2020, Earth Syst. Sci. Data Discuss. [preprint], doi: 10.5194/essd-2024-115, in review, 2024.