Soil organic carbon dust emission: an omitted global source of atmospheric CO2

Chappell, Adrian and Webb, Nicholas P. and Butler, Harry J. and Strong, Craig L. and McTainsh, Grant H. and Leys, John F. and Viscarra Rossel, Raphael A. (2013) Soil organic carbon dust emission: an omitted global source of atmospheric CO2. Global Change Biology , 19 (10). pp. 3238-3244. ISSN 1354-1013


Soil erosion redistributes soil organic carbon (SOC) within terrestrial ecosystems, to the atmosphere and oceans. Dust export is an essential component of the carbon (C) and carbon dioxide (CO2) budget because wind erosion contributes to the C cycle by removing selectively SOC from vast areas and transporting C dust quickly offshore; augmenting the net loss of C from terrestrial systems. However, the contribution of wind erosion to rates of C release and sequestration is poorly understood. Here, we describe how SOC dust emission is omitted from national C accounting, is an underestimated source of CO2 and may accelerate SOC decomposition. Similarly, long dust residence times in the unshielded atmospheric environment may considerably increase CO2 emission. We developed a first approximation to SOC enrichment for a well established dust emission model and quantified SOC dust emission for Australia (5.83 Tg CO2-e yr−1) and Australian agricultural soils (0.4 Tg CO2-e yr−1). These amount to underestimates for CO2 emissions of ≈10% from combined C pools in Australia (year = 2000), ≈5% from Australian Rangelands and ≈3% of Australian Agricultural Soils by Kyoto Accounting. Northern hemisphere countries with greater dust emission than Australia are also likely to have much larger SOC dust emission. Therefore, omission of SOC dust emission likely represents a considerable underestimate from those nations' C accounts. We suggest that the omission of SOC dust emission from C cycling and C accounting is a significant global source of uncertainty. Tracing the fate of wind-eroded SOC in the dust cycle is therefore essential to quantify the release of CO2 from SOC dust to the atmosphere and the contribution of SOC deposition to downwind C sinks.

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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: © 2013 John Wiley & Sons Ltd. Published online 29 Jul 2013. Users may not copy, distribute, transmit or otherwise reproduce, sell or resell any material nor add to any retrieval system or use in any paid service such as document delivery or list serve, or for use by any information brokerage or for systematic distribution, whether or not for commercial or non-profit use or for a fee or free of charge.
Faculty / Department / School: Current - Faculty of Health, Engineering and Sciences - School of Agricultural, Computational and Environmental Sciences
Date Deposited: 28 Aug 2013 23:08
Last Modified: 30 May 2017 06:48
Uncontrolled Keywords: Australia; carbon accounting; carbon budgets; carbon dioxide; dust emission; soil organic carbon
Fields of Research : 05 Environmental Sciences > 0503 Soil Sciences > 050301 Carbon Sequestration Science
03 Chemical Sciences > 0399 Other Chemical Sciences > 039901 Environmental Chemistry (incl. Atmospheric Chemistry)
05 Environmental Sciences > 0503 Soil Sciences > 050305 Soil Physics
Socio-Economic Objective: D Environment > 96 Environment > 9602 Atmosphere and Weather > 960201 Atmospheric Composition (incl. Greenhouse Gas Inventory)
Identification Number or DOI: 10.1111/gcb.12305

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