Contact: Sandra Hines
University of Washington
Caption: The distinctive signal of human-caused nitrogen going back more than 100 years appears in 25 lakes in temperate (green circles), alpine (blue) and arctic (red) areas of the Northern Hemisphere. Data from two lakes are shown in comparison to a similar signal revealed in the Greenland Ice Sheet (yellow).
Credit: University of Washington
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Related news release: Nitrogen from humans pollutes remote lakes for more than a century