Ozone column measurements vs. atmospheric chlorine inventory

by Wm. Robert Johnston
last updated 26 December 2002

Description: This graph plots monthly ozone column measurements (in Dobson Units) from Arosa, Switzerland (the longest available series) versus the amount of chlorine in the atmosphere from manmade chemicals (in millions of metric tons).

Comments: If the amount of man-made chlorine were the most important factor in the amount of atmospheric chlorine, this graph would show a line descending to the right. While a role for man-made chlorine is not ruled out by this data, other significant factors are clearly at play.

Sources: World Resources Institute et ali., World Resources 1998-99, 1998, Oxford Univ. Press (New York, NY) (anthropogenic chlorine).

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