A consensus has been reached within the scientific community concerning the occurrence of climate change and its anthropogenic causes. Outside of this community, however, there continues to be considerable debate and confusion surrounding the topic. The government mitigation strategies and political leadership needed for this issue will require the support of the public. University students represent an important sector of the US public, as they are young, educated citizens who are highly invested in our future. Studies examining public understanding of climate change in the 1990s through the present find that despite high levels of concern for the environment, members of the public frequently hold incorrect mental models of climate change. This dissertation examines current mental models of climate change, using a sample of undergraduate students at two Universities. Surveys were conducted at the University of Delaware and at the University of Maryland (853 respondents, 465 completed surveys) and semi-structured interviews were conducted at the University of Delaware (n = 26). This data was used to determine how students' mental models compare to the scientific model of climate change. Three primary aspects of climate change understanding are analyzed: the causes, the effects, and possible mitigation strategies. This research also examined the influence of scientific major and environmental group membership on understanding of climate change. Science major and membership in an environmental group were each found to increase student understanding of climate change science, but these two causes had greater effects on different components of their models. This dissertation demonstrates that young, educated US citizens have a limited understanding of the causes, effects, and mitigation strategies of climate change. This research also shows that students in science majors or in environmental groups are more likely to have mental models of climate that closely match the scientific model, and that environmental group membership is a stronger predictor of a more complete understanding than science major. In general, the most common misconceptions seen in students' mental models involved incorrect transfer to climate change models of inappropriate elements from models of other environmental issues, like ozone depletion or criteria pollutants. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]