Carbon dioxide sources from Alaska driven by increasing early winter respiration from Arctic tundra

• Published in: Proceedings of the National Academy of Sciences
• Main Authors: Commane, Róisín, Lindaas, Jakob, Benmergui, Joshua, Luus, Kristina A., Chang, Rachel Y.-W., Daube, Bruce C., Euskirchen, Eugénie S., Henderson, John M., Karion, Anna, Miller, John B., Miller, Scot M., Parazoo, Nicholas C., Randerson, James T., Sweeney, Colm, Tans, Pieter, Thoning, Kirk, Veraverbeke, Sander, Miller, Charles E., Wofsy, Steven C.
• Format: Text
• Language: English
• Published: National Academy of Sciences 2017
• Subjects: Physical Sciences; Arctic; Barrow; Climate change; permafrost; Tundra; Alaska
• Online Access: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5448179/; http://www.ncbi.nlm.nih.gov/pubmed/28484001; https://doi.org/10.1073/pnas.1618567114

Rising arctic temperatures could mobilize reservoirs of soil organic carbon trapped in permafrost. We present the first quantitative evidence for large, regional-scale early winter respiration flux, which more than offsets carbon uptake in summer in the Arctic. Data from the National Oceanic and Atmospheric Administration’s Barrow station indicate that October through December emissions of CO2 from surrounding tundra increased by 73% since 1975, supporting the view that rising temperatures have made Arctic ecosystems a net source of CO2. It has been known for over 50 y that tundra soils remain unfrozen and biologically active in early winter, yet many Earth System Models do not correctly represent this phenomenon or the associated CO2 emissions, and hence they underestimate current, and likely future, CO2 emissions under climate change.