Students from three different British Columbia grade six classes were followed through two weeks of instruction on climate change. Pre, post, and follow-up surveys were used to determine the differences in knowledge gained and retained by students that received direct instruction from their science teacher, and by those who received equivalent content instruction from outside presenters. The teacher participant also completed a survey on her experience with the researcher-designed lesson plans. Students' results on the surveys were compared to results from a control group with no intervention. The teacher-based setting resulted in significantly higher knowledge gain, although no difference was found between the groups' rate of knowledge decline thereafter. Highest gains in knowledge were for the carbon cycle and the human impacts topic, followed by understanding the difference between climate and weather. The students and teacher alike appeared to struggle with the topic of global warming and the greenhouse effect. The research suggests that with the appropriate background information the classroom teacher is likely to be more effective at conveying the science of climate change, particularly when it is taught through an understanding of the carbon cycle and its human impacts. It also suggests that those non-governmental organizations engaged in climate change education might be better served by investing their limited resources in the development of learning materials and subsequent professional development for teachers rather than focusing on in-school presentations. (Contains 2 tables and 4 figures.)