A study examines trends in ocean carbon sinks over the course of two decades. Because atmospheric CO2 is not solely the result of anthropogenic emissions, efforts are underway to determine the array of factors that influence atmospheric levels of CO2. Tim DeVries and colleagues combined an ocean circulation inverse model, pCO2-based flux mapping models, and global ocean biogeochemistry models to estimate decadal variability in oceanic CO2 uptake between 1990 and 2009. The authors found that the ocean carbon sink may be responsible for approximately 10-40% of the observed decadal variability of CO2 buildup in the atmosphere. The models consistently found an increased oceanic carbon sink in the 2000s compared with the 1990s. The authors also found that currently used carbon cycle models underestimate decadal variability of oceanic and terrestrial CO2 sinks. The findings suggest that CO2 uptake is highly sensitive to climate variability, and current oceanic and terrestrial models might underestimate this sensitivity. Therefore, current models may not provide accurate predictions of the decadal variability of the global carbon budget, according to the authors.
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Article #19-00371: "Decadal trends in the ocean carbon sink," by Tim DeVries et al.
MEDIA CONTACT: Tim DeVries, University of California, Santa Barbara, CA; email: <tdevries@geog.ucsb.edu>
Journal
Proceedings of the National Academy of Sciences