Understanding the role of chlorofluorocarbons in global atmospheric change
James Andrew Rye 1998 Journal of Geoscience Education v46, p.488-493
The dual role of chlorofluorocarbons (CFCs) in global atmospheric change, and the related feedbacks between ozone-layer depletion and greenhouse warming, reflect the complexity of climate-change issues. Science instruction that targets such issues can make a vital contribution to global scientific literacy from an Earth-systems perspective. This study focused on global atmospheric change instruction for eighth-grade students. Pre-instructional interviews revealed that over 60 percent of students had little to no understanding of CFCs; about 30 percent connected them to ozone-layer destruction, and a few had misconceptions about the ozone hole heating up earth. An analysis of students' post-instructional concept maps suggested that knowledge about CFCs was limited to their role in ozone-layer depletion. Post-instructional interview transcripts corroborated these findings and revealed further that about 30 percent held the misconception that CFCs cause global warming by depleting the ozone layer and letting in more ultraviolet rays or sunlight. These findings suggest that instruction on the role of CFCs in global atmospheric change needs to clarify further the differences between infrared and ultraviolet radiation and might emphasize the greenhouse nature of CFCs prior to dealing with their role in ozone-layer depletion.
