Misconceptions About the Greenhouse Effect

Journal of Geoscience Education, May 2006 by Gautier, Catherine, Deutsch, Katie, Rebich, Stacy

ABSTRACT

Studies have shown that both students and the general public possess many misconceptions about the processes involved in the greenhouse effect and ozone depletion. This study, conducted in a mock summit class on global climate change, explored the level of understanding and the nature of students' misconceptions about climate. Several times throughout the class, students responded to a set of questions about the greenhouse effect. Through analysis of their responses, we were able to track changes in students' mental models, evaluate the degree to which they were able to overcome misconceptions, and assess the permanence of the newly achieved understanding.

Based on these results, we comment on the potential role of these students in public decision making related to global climate change, and discuss ways in which misconceptions could impede sound judgment on issues related to climate policy. Based on previous experiences with both teaching and assessing student learning about global climate change, we propose key principles that we consider minimum knowledge for an undergraduate student in Earth Science. We suggest that Earth science educators should focus on identification of key principles in all areas of the discipline and use those as the basis for curriculum development.

INTRODUCTION

Misconceptions about climate processes, especially those involving confusion between the phenomena of ozone depletion and global warming, are commonly observed in discussions of climate and atmospheric change. Many people and students (e.g., Rebich and Gautier, 2005) believe that the Earth is warming as a result of more solar radiation entering the atmosphere through the ozone hole. Since we have observed this confusion in our Earth System Science (ESS) classes throughout the past decade, we decided to undertake a more thorough investigation of our students' misconceptions about climate. We started by focusing our studies on the greenhouse effect with the ultimate intention of characterizing the main misconceptions in Earth system science, assessing their origin and ultimately remedying them through a variety of instructional interventions.

The first phase of our study involved the development or assessment tools to investigate the nature and characteristics of the misconceptions student have about the greenhouse effect. A first tool, concept mapping - a structured network of propositions (statements of relationship between concepts) that provides a visual representation of complex information - was initially employed for this investigation. Our work (Rebich and Gautier, 2005) included a thorough analysis of conceptual change that occurred as a result of ESS instruction in the form of a mock summit class. The goal of this role-playing class (Gautier and Rebich, 2005) is to review the oasic scientific concepts underlying climate change (see Table l:Topics Used for Evaluation - section 4 on Instructional setting and Methodology) and to investigate actions that could be taken to abate the impacts of climate change now and in the future. Through our concept map assessment, we observed that students displayed significant increases in the breadth and interconnectedness of their knowledge of climate change between the beginning and the end of the class. More importantly with regards to the topic of the present paper, we uncovered a set of commonly held misconceptions regarding the greenhouse effect and aerosols. In this paper, we report the results of a study designed to further explore the nature of these common misconceptions and characterize how they evolve as a function of remedial lecture-based instruction. The next phase of our research will build upon this study and investigate how other non-traditional instructional approaches and specific types of learning activities could effectively help students Become aware of their flawed mental models and correct their misconceptions.

This paper describes the results from this study which analyzes the evolution of misconceptions in a classroom setting as a function of evolving instruction. In section 2, we provide a brief background about misconceptions and conceptual change. In section 3, we review prior findings (Rebich and Gautier, 2005) about misconceptions that we identified through study of an earlier mock summit class. section 4 describes the instructional setting, study methodology, and the instrument we usea to assess the misconceptions. In section 5, we present our results and discuss now they relate to individual performance in the course. section 6 provides some preliminary conclusions about how the student's concepts and misconceptions concerning the greenhouse effect have evolved as a result or our instruction. We also review the importance of fully understanding the greenhouse effect, and we suggest that carefully selecting fundamental concepts in Earth system science and using a learner-centered instructional approach will help to ensure that our students are able to understand these important concepts and overcome their misconceptions.