How much of Earth's organic carbon is buried in ocean sediments? And how much stays 'buried'?
Quantifying the organic carbon sink in marine sediments is crucial for assessing how the marine carbon cycle regulates Earth’s climate. We argue that Burial efficiency (BE) – the commonly-used metric reporting the percentage of organic carbon that becomes 'buried', is loosely defined, misleading, and inconsistent. We use a global diagenetic model to highlight vastly different BE’s depending on sediment depth or age horizons used to calculate BE. Instead, we propose using transfer efficiencies (Teff’s) for quantifying sediment OC burial. This metric requires precise specification of spatial or temporal references, and emphasizes that OC degradation continues beyond these horizons. Ultimately, quantifying OC burial with precise sediment-depth and sediment-age-resolved metrics will enable a more consistent and transferable assessment of OC fluxes through the Earth system.
The open access paper is available here:
Bradley J° Hülse D°, LaRowe D, Arndt S (2022) Transfer Efficiency of Organic Carbon in Marine Sediments. Nature Communications. doi:10.1038/s41467-022-35112-9 (°co-first authors)