| Title | Wetland emission and atmospheric sink changes explain methane growth in 2020 |
| Authors | Peng, Shushi Lin, Xin Thompson, Rona L. Xi, Yi Liu, Gang Hauglustaine, Didier Lan, Xin Poulter, Benjamin Ramonet, Michel Saunois, Marielle Yin, Yi Zhang, Zhen Zheng, Bo Ciais, Philippe |
| Affiliation | Peking Univ, Coll Urban & Environm Sci, Sino French Inst Earth Syst Sci, Beijing, Peoples R China Peking Univ, Lab Earth Surface Proc, Beijing, Peoples R China Peking Univ, Inst Carbon Neutral, Beijing, Peoples R China Univ Paris Saclay, Lab Sci Climat & Environm, LSCE, IPSL,CEA,CNRS,UVSQ, Gif Sur Yvette, France Norwegian Inst Air Res NILU, Kjeller, Norway Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO USA NOAA, Global Monitoring Lab, Boulder, CO USA NASA, Goddard Space Flight Ctr, Biospher Sci Lab, Greenbelt, MD USA CALTECH, Div Geol & Planetary Sci, Pasadena, CA USA Univ Maryland, Dept Geog Sci, College Pk, MD USA Tsinghua Univ, Inst Environm & Ecol, Tsinghua Shenzhen Int Grad Sch, Shenzhen, Peoples R China State Environm Protect Key Lab Sources & Control A, Beijing, Peoples R China Cyprus Inst, Climate & Atmosphere Res Ctr CARE C, Nicosia, Cyprus |
| Keywords | MODEL DESCRIPTION CLIMATE-CHANGE SENSITIVITY SATELLITE ORCHIDEE TRENDS BUDGET CH4 CO2 |
| Issue Date | 15-Dec-2022 |
| Publisher | NATURE |
| Abstract | Atmospheric methane growth reached an exceptionally high rate of 15.1 +/- 0.4 parts per billion per year in 2020 despite a probable decrease in anthropogenic methane emissions during COVID-19 lockdowns(1). Here we quantify changes in methane sources and in its atmospheric sink in 2020 compared with 2019. We find that, globally, total anthropogenic emissions decreased by 1.2 +/- 0.1 teragrams of methane per year (Tg CH(4)yr(-1)), fire emissions decreased by 6.5 +/- 0.1 Tg CH(4)yr(-1) and wetland emissions increased by 6.0 +/- 2.3 Tg CH(4)yr(-1). Tropospheric OH concentration decreased by 1.6 +/- 0.2 per cent relative to 2019, mainly as a result of lower anthropogenic nitrogen oxide (NOx) emissions and associated lower free tropospheric ozone during pandemic lockdowns(2). From atmospheric inversions, we also infer that global net emissions increased by 6.9 +/- 2.1 Tg CH(4)yr(-1) in 2020 relative to 2019, and global methane removal from reaction with OH decreased by 7.5 +/- 0.8 Tg CH(4)yr(-1). Therefore, we attribute the methane growth rate anomaly in 2020 relative to 2019 to lower OH sink (53 +/- 10 per cent) and higher natural emissions (47 +/- 16 per cent), mostly from wetlands. In line with previous findings(3,4), our results imply that wetland methane emissions are sensitive to a warmer and wetter climate and could act as a positive feedback mechanism in the future. Our study also suggests that nitrogen oxide emission trends need to be taken into account when implementing the global anthropogenic methane emissions reduction pledge'. |
| URI | http://hdl.handle.net/20.500.11897/667769 |
| ISSN | 0028-0836 |
| DOI | 10.1038/s41586-022-05447-w |
| Indexed | SCI(E) |
| Appears in Collections: | 城市与环境学院 地表过程分析与模拟教育部重点实验室 |
