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.

北方-北极地区的湿地甲烷 (CH ₄ ) 排放容易受到气候变化的影响，并与气候反馈相关，但对其长期动态的了解仍不确定。在这里，我们升级并分析了二十年（2002-2021 年）北方-北极湿地 CH ₄排放量，这代表了涡流协方差和室观测的前所未有的汇编。我们发现 CH ₄排放量呈强劲增长趋势(+8.9%)，且具有很强的年际变化。大部分排放量增加发生在初夏（六月和七月），主要是由变暖（52.3%）和生态系统生产力（40.7%）驱动的。此外，2016年2°C的温度异常导致该地区年度CH ₄排放量达到最高记录（22.3 Tg CH ₄  yr ^-1），这主要是由西西伯利亚低地的高排放造成的。然而，全球碳项目的当前模型未能捕捉到排放量和趋势，并且可能会对未来因北北极变暖和绿化加剧而驱动的湿地 CH _{4排放量的估计产生偏差。}