Editor's Summary
24 January 2008
Dirty ol' man river
The flow of dissolved inorganic carbon from rivers to the oceans is an important net flux connecting the terrestrial and marine carbon reservoirs. Now a remarkable 100-year record of bicarbonate determinations, made at water treatment plants in the towns of Carrollton and Algiers, has been used as a basis for a study of Mississippi River water and carbon fluxes. Previous work revealed a significant increase the amount of dissolved inorganic carbon, mostly bicarbonate, exported by the Mississippi to the ocean over the past 50 years, but the cause for the increase remained uncertain. The Carrollton/Algiers data, together with sub-watershed and precipitation data, point to a mainly anthropogenic origin — increased bicarbonate discharge from agricultural watersheds that was not balanced by a rise in precipitation.
News and Views: Carbon cycle: Harvest of the century
A century-long record of levels of inorganic carbon in the Mississippi, extracted from the water-treatment plants of New Orleans, documents the changes wrought by shifting agricultural practices in the river's basin.
Emilio Mayorga
doi:10.1038/451405a
Letter: Anthropogenically enhanced fluxes of water and carbon from the Mississippi River
Peter A. Raymond, Neung-Hwan Oh, R. Eugene Turner & Whitney Broussard
doi:10.1038/nature06505
First paragraph | Full Text | PDF (313K) | Supplementary information
