Inland water greenhouse gas emissions offset the terrestrial carbon sink in the northern cryosphere

Chunlin Song; Shaoda Liu; Genxu Wang; Liwei Zhang; Judith A Rosentreter; Gang Zhao; Xiangyang Sun; Yuanzhi Yao; Cuicui Mu; Shouqin Sun; Zhaoyong Hu; Shan Lin; Juying Sun; Yang Li; Ying Wang; Yuhao Li; Peter A Raymond; Jan Karlsson

doi:10.1126/sciadv.adp0024

Inland water greenhouse gas emissions offset the terrestrial carbon sink in the northern cryosphere

Sci Adv. 2024 Sep 27;10(39):eadp0024. doi: 10.1126/sciadv.adp0024. Epub 2024 Sep 27.

Authors

Chunlin Song¹, Shaoda Liu², Genxu Wang¹, Liwei Zhang³, Judith A Rosentreter⁴, Gang Zhao⁵, Xiangyang Sun¹, Yuanzhi Yao⁶, Cuicui Mu⁷, Shouqin Sun¹, Zhaoyong Hu¹, Shan Lin¹, Juying Sun¹, Yang Li¹, Ying Wang¹, Yuhao Li¹, Peter A Raymond⁸, Jan Karlsson⁹

Affiliations

¹ State Key Laboratory of Hydraulics and Mountain River Engineering, College of Water Resource and Hydropower, Sichuan University, Chengdu, Sichuan 610065, China.
² State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China.
³ State Key Laboratory of Estuarine and Coastal Research, Yangtze Delta Estuarine Wetland Ecosystem Observation and Research Station, East China Normal University, Shanghai, China.
⁴ Center for Coastal Biogeochemistry, Faculty of Science and Engineering, Southern Cross University, Lismore, New South Wales, Australia.
⁵ Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China.
⁶ School of Geographic Sciences, East China Normal University, Shanghai, China.
⁷ Key Laboratory of Western China's Environmental Systems (Ministry of Education), College of Earth and Environmental Sciences, Observation and Research Station on Eco-Environment of Frozen Ground in the Qilian Mountains, Lanzhou University, Lanzhou, China.
⁸ School of the Environment, Yale University, New Haven, CT 06511, USA.
⁹ Climate Impacts Research Centre (CIRC), Department of Ecology and Environmental Science, Umeå University, Linnaeus väg 6, 901 87 Umeå, Sweden.

Abstract

Climate-sensitive northern cryosphere inland waters emit greenhouse gases (GHGs) into the atmosphere, yet their total emissions remain poorly constrained. We present a data-driven synthesis of GHG emissions from northern cryosphere inland waters considering water body types, cryosphere zones, and seasonality. We find that annual GHG emissions are dominated by carbon dioxide ([Formula: see text] teragrams of CO₂; [Formula: see text]) and methane ([Formula: see text] teragrams of CH₄), while the nitrous oxide emission ([Formula: see text] gigagrams of N₂O) is minor. The annual CO₂-equivalent (CO₂e) GHG emissions from northern cryosphere inland waters total [Formula: see text] or [Formula: see text] petagrams of CO₂e using the 100- or 20-year global warming potentials, respectively. Rivers emit 64% more CO₂e GHGs than lakes, despite having only one-fifth of their surface area. The continuous permafrost zone contributed half of the inland water GHG emissions. Annual CO₂e emissions from northern cryosphere inland waters exceed the region's terrestrial net ecosystem exchange, highlighting the important role of inland waters in the cryospheric land-aquatic continuum under a warming climate.