(Sarah of the Clue Crew reports from a beach UC San Diego's Scripps Institution of Oceanography.)  In 1958, Scripps scientist Charles Keeling began using flasks to measure this gas in the atmosphere; the "Keeling curve" is a symbol of climate change
[DOC] [TLE] Keeling Curve - Wikipedia [PAR] The Keeling Curve is a graph which plots the ongoing change in concentration of 
carbon dioxide in Earth's atmosphere since 1958.