Observation-constrained sensitivities of Arctic methane emissions to warming

• 成果类型: Article
• 署名作者: Liu, Gang; Peng, Shushi; Shen, Lu; Ciais, Philippe; Nisbet, Euan G.; Lan, Xin; Michel, Sylvia E.
• 署名单位: Peking University; Peking University; Peking University; Universite Paris Saclay; Centre National de la Recherche Scientifique (CNRS); CEA; University of London; Royal Holloway University London; University of Colorado System; University of Colorado Boulder; University of Colorado System; University of Colorado Boulder; University of Colorado System; University of Colorado Boulder
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.2523274123
• 发表日期: 2026-07-07
• 页码: e2523274123
• 关键词: methane; methane carbon isotope; wetlands; wildfire; Arctic; atmospheric methane; CLIMATE-CHANGE; satellite; models; evaporation; permafrost; lakes; sink; soil

摘要

The sensitivity of pan-Arctic (60 to 90 degrees N) natural methane emissions to climate warming lacks direct observational constraints. Long-term atmospheric measurements of methane, which reflect integrated Arctic fluxes and atmospheric transport, show that in the pan-Arctic the autumn-to-winter CH4 build-up (as indicated by the autumn zero crossing date) is becoming earlier. This advancing trend in autumn zero crossing date is explained by growing natural Arctic CH4 emissions in response to climate warming in July, August and September, with a rate of increase of 0.14 +/- 0.04 Tg CH4 y-2 during the period 1998-2020. Atmospheric delta 13CCH4 observational records allowed us to attribute this increase to 0.08 +/- 0.02 Tg CH4 y-2 from natural biogenic emissions (wetlands, lakes, permafrost soils) and 0.06 +/- 0.02 Tg CH4 y-2 from wildfire emissions. Our results point to a larger warming sensitivity of natural emissions (3.1 +/- 0.9 Tg CH4 y-1 per degrees C) than previous estimates, and potentially a larger positive feedback on climate warming.