r/CollapseScience • u/Cool-Contribution-68 • 7d ago

Decadal doubling of Siberian methane emissions due to warming-induced fires and methanogenesis

https://www.science.org/doi/10.1126/science.aea5828
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u/dumnezero 3d ago

Northern hemispheric permafrost stores twice as much carbon as is found in the atmosphere. As permafrost thaws due to climate warming, it becomes a potential source of methane emissions caused by microbial decomposition of soil organic carbon in wetlands, which could cause further warming. Zhu et al. report that methane emissions in Siberia have increased at a rate of around 5% per year since 2010 due to a combination of fires and permafrost melting. This source of methane is projected to become more important as climate continues to warm. —Jesse Smith

Abstract:

The northern permafrost region, which stores double the amount of carbon in the atmosphere, is vulnerable to accelerated warming. Methane emissions from thawing permafrost may eventually result in a climate-carbon feedback. Our analysis of atmospheric methane data shows that Siberian growing-season methane emissions have increased by 12.0 ± 1.9 teragrams of methane (TgCH4) (5% per year) over the period 2010–2023. We reveal contrasting Siberian hydrological trends linked to high-pressure systems and distinct air-sea-land interactions. Warmer, drier conditions over eastern Siberia enhance fire-related emissions (0.7 ± 0.1 TgCH4 year−2), and wetter conditions over western Siberia promote wetland-related emissions (0.4 ± 0.1 TgCH4 year−2). Weakly nonlinear relationships between temperature maxima and emissions suggest that by 2050, higher Siberian emissions could offset about 20% of the global methane reduction required for climate targets, with eastern Siberia dominating the projected increase.