Overcoming students' misconceptions may be a challenge when teaching about phenomena such as climate change. Students tend to cite short-term weather effects as evidence to support or refute long-term climate transformations, which displays a fundamental misunderstanding about weather and climate distinctions. Confusion about weather and climate may also reflect student misunderstanding about deep time, a concept that spans several scientific content areas. This study examines the relationships between students' understanding of deep time and their understandings of the distinctions between weather and climate, as well as how these understandings influence students' perceptions about the plausibility of human-induced global climate change. Undergraduate students enrolled in an introductory science class on global climate change completed measures of their (a) understanding of distinctions between weather and climate, (b) knowledge of deep time, and (c) plausibility perceptions of human-induced climate change, both at the beginning and end of the course. The study includes comparison groups of similar students enrolled in introductory physical geography classes. Results revealed that greater knowledge of deep time and increased plausibility perceptions of human-induced climate change provide significant explanation of variance in students' understanding of weather and climate distinctions. Furthermore, students achieve significantly increased understanding of weather and climate, even with brief instruction.