Atmospheric concentrations of two CFCs, 1977-2002

by Wm. Robert Johnston
last updated 26 December 2002

Description: The lines show a twelve-month moving average of measured concentrations of CFC-11 (blue line) and CFC-12 (red line) at the surface. The data shown is the average of measurements from Barrow, Alaska, and Mauna Loa, Hawaii (missing values were extrapolated).



© 2001, 2002 by Wm. Robert Johnston.
Last modified 26 December 2002.
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