Thermokarst lakes, serving as significant sources of methane (CH), play a crucial role in affecting the feedback of permafrost carbon cycle to global warming. However, accurately assessing CH emissions from these lakes remains challenging due to limited observations during lake ice melting periods. In this study, by integrating field surveys with machine learning modeling, we offer a comprehensive assessment of present and future CH emissions from thermokarst lakes on the Tibetan Plateau. Our results reveal that the previously underestimated CH release from lake ice bubble and water storage during ice melting periods is 11.2 ± 1.6 Gg C of CH, accounting for 17 ± 4% of the annual total release from lakes. Despite thermokarst lakes cover only 0.2% of the permafrost area, they annually emit 65.5 ± 10.0 Gg C of CH, which offsets 6.4% of the net carbon sink in alpine grasslands on the plateau. Considering the loss of lake ice, the expansion of thermokarst lakes is projected to lead to 1.1-1.2 folds increase in CH emissions by 2100. Our study allows foreseeing future CH emissions from the rapid expanding thermokarst lakes and sheds new lights on processes controlling the carbon-climate feedback in alpine permafrost ecosystems.
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http://dx.doi.org/10.1038/s41467-025-57745-2 | DOI Listing |
Nat Commun
March 2025
National Tibetan Plateau Data Center, State Key Laboratory of Tibetan Plateau Earth System, Environment and Resource, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China.
Thermokarst lakes, serving as significant sources of methane (CH), play a crucial role in affecting the feedback of permafrost carbon cycle to global warming. However, accurately assessing CH emissions from these lakes remains challenging due to limited observations during lake ice melting periods. In this study, by integrating field surveys with machine learning modeling, we offer a comprehensive assessment of present and future CH emissions from thermokarst lakes on the Tibetan Plateau.
View Article and Find Full Text PDFFront Microbiol
February 2025
Biological & Chemical Sensors, Sandia National Laboratories, Albuquerque, NM, United States.
Permafrost thaw increases the bioavailability of ancient organic matter, facilitating microbial metabolism of volatile organic compounds (VOCs), carbon dioxide, and methane (CH). The formation of thermokarst (thaw) lakes in icy, organic-rich Yedoma permafrost leads to high CH emissions, and subsurface microbes that have the potential to be biogeochemical drivers of organic carbon turnover in these systems. However, to better characterize and quantify rates of permafrost changes, methods that further clarify the relationship between subsurface biogeochemical processes and microbial dynamics are needed.
View Article and Find Full Text PDFISME Commun
January 2025
Centre Eau Terre Environnement, Institut national de la recherche scientifique, 490 rue de la couronne, Quebec City, QC G1K 9A9, Canada.
Rising air temperatures and permafrost degradation drive the erosion of palsas (permafrost mounds mainly composed of frozen peat and ice layers) and lead to the formation of thermokarst ponds and lakes, known for their high greenhouse gas (GHG) emissions. This study investigates the impact of permafrost soil erosion during thermokarst lake formation on microbial community structure and its implications for GHG dynamics in a highly degraded permafrost valley (Nunavik, northern Quebec, Canada). Samples were collected from a palsa, an emerging lake connected to the palsa, surrounding peat and soil pore water, and two mature lakes which are older, stratified, and less connected to the palsa.
View Article and Find Full Text PDFSci Rep
February 2025
Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), University of Porto, Porto, Portugal.
Permafrost soils are critical reservoirs for mercury (Hg), with the thawing process leading to the release of this element into the environment, posing significant environmental risks. Of particular concern is the methylated form of mercury, monomethylmercury (MMHg), known for its adverse effects on Human health. Microbial communities play a pivotal role in the formation of MMHg by facilitating Hg methylation and in the demethylation of MMHg, slowing the crossing of toxic threshold concentration in the environment.
View Article and Find Full Text PDFNat Commun
February 2025
State Key Laboratory of Herbage Improvement and Grassland Agroecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, China.
Thermokarst lakes as hot spots of methane (CH) release are crucial for predicting permafrost carbon feedback to global warming. These lakes are suffering from serious drainage events, however, the impacts of lake drainage on CH release remain unclear. Here, synthesizing field drilling, incubation experiments, and carbon composition and microbial communities, we reveal the temperature sensitivities (Q) and drivers of CH release from drainage-affected lakes on the Qinghai-Tibet Plateau.
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