This study was designed to explore the effects of different geographical background contexts and signalling for information about global warming on comprehension, recall and cognitive load. Two different geographical contexts, US and Korean, were employed to frame explanations of global warming phenomena to US students. Two signalling conditions were also adopted in which passages about global warming were either signalled or nonsignalled. Comparisons within the experimental framework of the study showed that context familiarity had positive effects on students' deep comprehension (knowledge application), self-reported levels of motivation and perceived levels of difficulty, and that signalling had a negative effect on deep comprehension. An expertise reversal effect was also noted. The findings of the current study imply that to-be-learned information framed within an unfamiliar context can create disadvantages for students' motivation, perceived difficulty and deep comprehension.