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Arctic Amplification of Global Warming Strengthened by Sunlight Oxidation of Permafrost Carbon to CO 2
Author(s) -
Bowen J. C.,
Ward C. P.,
Kling G. W.,
Cory R. M.
Publication year - 2020
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2020gl087085
Subject(s) - permafrost , dissolved organic carbon , soil water , carbon dioxide , environmental science , arctic , carbon fibers , environmental chemistry , total organic carbon , atmosphere (unit) , soil carbon , carbon cycle , atmospheric sciences , soil science , ecosystem , geology , chemistry , ecology , oceanography , materials science , meteorology , physics , organic chemistry , biology , composite number , composite material
Once thawed, up to 15% of the ∼1,000 Pg of organic carbon (C) in arctic permafrost soils may be oxidized to carbon dioxide (CO 2 ) by 2,100, amplifying climate change. However, predictions of this amplification strength ignore the oxidation of permafrost C to CO 2 in surface waters (photomineralization). We characterized the wavelength dependence of permafrost dissolved organic carbon (DOC) photomineralization and demonstrate that iron catalyzes photomineralization of old DOC (4,000–6,300 a BP) derived from soil lignin and tannin. Rates of CO 2 production from photomineralization of permafrost DOC are twofold higher than for modern DOC. Given that model predictions of future net loss of ecosystem C from thawing permafrost do not include the loss of CO 2 to the atmosphere from DOC photomineralization, current predictions of an average of 208 Pg C loss by 2,299 may be too low by ~14%.