PerspectiveGeochemistry

A New Story from the Ol' Man River

Science  04 Jul 2003:
Vol. 301, Issue 5629, pp. 56-58
DOI: 10.1126/science.1086419

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Summary

Planting trees is one approach to reducing the concentration of carbon dioxide in the atmosphere. But, as Ittekkot explains in his Perspective, converting croplands to forests in river catchments may actually reduce terrestrial carbon dioxide removal via chemical weathering and river transport. He highlights the report by Raymond and Cole, who have analyzed alkalinity data for the Mississippi River. Over the past 50 years, alkalinity export by the Mississippi has steadily increased, with the largest increase in tributaries with the highest percent land coverage in croplands. The process must be considered in studies of carbon dioxide sinks.