This readings answers the riddle of how such large ozone losses could occur in such a short time and why they should occur in such a strange place as Antarctica. The basic chemical concepts here are chemical reactions, catalysis, and if your students are advanced enough you may want to discuss the notion of heterogenous reactions and catalysis, that is, reactions between reactants in different states. In this case, the heterogenous reactions are between gaseous ClNO₂ and the liquid and solid particles of polar stratospheric clouds.

It should be stressed again to the students that the Antarctic ozone hole was not predicted by any computer models, and it is very possible for ecological damage to occur quickly, without warning, and to be much more severe than anyone could have predicted.

Relevant National Science Education Standards

Unifying Concepts and Processes — The reading deals with the interactions of components of the stratosphere over Antarctica, and how those parts contribute to the overall behavior of the system.

Physical Science — The reading deals with the molecular nature of matter, chemical reactions, and the interaction of matter with energy in the form of UV radiation.

Earth and Space Science — The reading deals geochemical processes of the polar stratosphere.

Science in Personal and Social Perspectives — The reading involves an environmental quality issue which is also a human-induced health hazard, plus the use of science in understanding this global challenge.

Next: Swapping Atoms

The Montreal Protocol on Substances that deplete the Ozone Layer—from the United Nations Environment Programme Ozone Secretariat.

Reference

Solomon, Susan. "Stratospheric ozone depletion: a review of concepts and history," Reviews of Geophysics, 1999, 37, 275-316.