TY - JOUR
T1 - Reduced net methane emissions due to microbial methane oxidation in a warmer Arctic
AU - Oh, Youmi
AU - Zhuang, Qianlai
AU - Liu, Licheng
AU - Welp, Lisa R.
AU - Lau, Maggie C.Y.
AU - Onstott, Tullis C.
AU - Medvigy, David
AU - Bruhwiler, Lori
AU - Dlugokencky, Edward J.
AU - Hugelius, Gustaf
AU - D’Imperio, Ludovica
AU - Elberling, Bo
N1 - Publisher Copyright:
© 2020, The Author(s), under exclusive licence to Springer Nature Limited.
PY - 2020/4/1
Y1 - 2020/4/1
N2 - Methane emissions from organic-rich soils in the Arctic have been extensively studied due to their potential to increase the atmospheric methane burden as permafrost thaws1–3. However, this methane source might have been overestimated without considering high-affinity methanotrophs (HAMs; methane-oxidizing bacteria) recently identified in Arctic mineral soils4–7. Herein we find that integrating the dynamics of HAMs and methanogens into a biogeochemistry model8–10 that includes permafrost soil organic carbon dynamics3 leads to the upland methane sink doubling (~5.5 Tg CH4 yr−1) north of 50 °N in simulations from 2000–2016. The increase is equivalent to at least half of the difference in net methane emissions estimated between process-based models and observation-based inversions11,12, and the revised estimates better match site-level and regional observations5 , 7 , 13–15. The new model projects doubled wetland methane emissions between 2017–2100 due to more accessible permafrost carbon16–18. However, most of the increase in wetland emissions is offset by a concordant increase in the upland sink, leading to only an 18% increase in net methane emission (from 29 to 35 Tg CH4 yr−1). The projected net methane emissions may decrease further due to different physiological responses between HAMs and methanogens in response to increasing temperature19,20.
AB - Methane emissions from organic-rich soils in the Arctic have been extensively studied due to their potential to increase the atmospheric methane burden as permafrost thaws1–3. However, this methane source might have been overestimated without considering high-affinity methanotrophs (HAMs; methane-oxidizing bacteria) recently identified in Arctic mineral soils4–7. Herein we find that integrating the dynamics of HAMs and methanogens into a biogeochemistry model8–10 that includes permafrost soil organic carbon dynamics3 leads to the upland methane sink doubling (~5.5 Tg CH4 yr−1) north of 50 °N in simulations from 2000–2016. The increase is equivalent to at least half of the difference in net methane emissions estimated between process-based models and observation-based inversions11,12, and the revised estimates better match site-level and regional observations5 , 7 , 13–15. The new model projects doubled wetland methane emissions between 2017–2100 due to more accessible permafrost carbon16–18. However, most of the increase in wetland emissions is offset by a concordant increase in the upland sink, leading to only an 18% increase in net methane emission (from 29 to 35 Tg CH4 yr−1). The projected net methane emissions may decrease further due to different physiological responses between HAMs and methanogens in response to increasing temperature19,20.
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U2 - 10.1038/s41558-020-0734-z
DO - 10.1038/s41558-020-0734-z
M3 - Article
AN - SCOPUS:85082944696
SN - 1758-678X
VL - 10
SP - 317
EP - 321
JO - Nature Climate Change
JF - Nature Climate Change
IS - 4
ER -