Boreal–Arctic wetland methane emissions modulated by warming and vegetation activity

• Main Authors: Yuan, Kunxiaojia, Li, Fa, McNicol, Gavin, Chen, Min, Hoyt, Alison, Knox, Sara, Riley, William J, Jackson, Robert, Zhu, Qing
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: eScholarship, University of California 2024
• Subjects: Earth Sciences; Climate Change Impacts and Adaptation; Environmental Sciences; Climate Action; Biogeochemistry; Climate sciences; Atmospheric Sciences; Physical Geography and Environmental Geoscience; Environmental Science and Management; Arctic; Climate change
• Online Access: https://escholarship.org/uc/item/4jz005z7

Wetland methane (CH4) emissions over the Boreal-Arctic region are vulnerable to climate change and linked to climate feedbacks, yet understanding of their long-term dynamics remains uncertain. Here, we upscaled and analysed two decades (2002-2021) of Boreal-Arctic wetland CH4 emissions, representing an unprecedented compilation of eddy covariance and chamber observations. We found a robust increasing trend of CH4 emissions (+8.9%) with strong inter-annual variability. The majority of emission increases occurred in early summer (June and July) and were mainly driven by warming (52.3%) and ecosystem productivity (40.7%). Moreover, a 2 °C temperature anomaly in 2016 led to the highest recorded annual CH4 emissions (22.3 Tg CH4 yr-1) over this region, driven primarily by high emissions over Western Siberian lowlands. However, current-generation models from the Global Carbon Project failed to capture the emission magnitude and trend, and may bias the estimates in future wetland CH4 emission driven by amplified Boreal-Arctic warming and greening.