Anthropogenic perturbation of the carbon fluxes from land to ocean

TitleAnthropogenic perturbation of the carbon fluxes from land to ocean
Publication TypeJournal Article
Year of Publication2013
AuthorsRegnier P., Friedlingstein P., Ciais P., Mackenzie F.T, Gruber N, Janssens I.A, Laruelle G.G, Lauerwald R., Luyssaert S., Andersson AJ, Arndt S., Arnosti C., Borges A.V, Dale A.W, Gallego-Sala A., Godderis Y., Goossens N., Hartmann J., Heinze C, Ilyina T., Joos F., LaRowe D.E, Leifeld J., Meysman F.JR, Munhoven G., Raymond P.A, Spahni R., Suntharalingam P., Thullner M.
JournalNature Geoscience
Volume6
Pagination597-607
Date Published2013/08
Type of ArticleReview
ISBN Number1752-0894
Accession NumberWOS:000322441900008
Keywordsagricultural soil-erosion; atmospheric; co2; coastal ocean; cycle; dioxide; organic-carbon; river sediment; sinks; terrestrial; united-states
Abstract

A substantial amount of the atmospheric carbon taken up on land through photosynthesis and chemical weathering is transported laterally along the aquatic continuum from upland terrestrial ecosystems to the ocean. So far, global carbon budget estimates have implicitly assumed that the transformation and lateral transport of carbon along this aquatic continuum has remained unchanged since pre-industrial times. A synthesis of published work reveals the magnitude of present-day lateral carbon fluxes from land to ocean, and the extent to which human activities have altered these fluxes. We show that anthropogenic perturbation may have increased the flux of carbon to inland waters by as much as 1.0 Pg C yr(-1) since pre-industrial times, mainly owing to enhanced carbon export from soils. Most of this additional carbon input to upstream rivers is either emitted back to the atmosphere as carbon dioxide (similar to 0.4 Pg C yr(-1)) or sequestered in sediments (similar to 0.5 Pg C yr(-1)) along the continuum of freshwater bodies, estuaries and coastal waters, leaving only a perturbation carbon input of similar to 0.1 Pg C yr(-1) to the open ocean. According to our analysis, terrestrial ecosystems store similar to 0.9 Pg C yr(-1) at present, which is in agreement with results from forest inventories but significantly differs from the figure of 1.5 Pg C yr(-1) previously estimated when ignoring changes in lateral carbon fluxes. We suggest that carbon fluxes along the land-ocean aquatic continuum need to be included in global carbon dioxide budgets.

DOI10.1038/ngeo1830
Short TitleNat. Geosci.
Integrated Research Themes: 
Student Publication: 
No