Researchers engaging in science communication tend to present information that they find most important. However, understanding the level of prior knowledge and interest of a target audience is key for effective communication of science, especially when dealing with complex and mediatic themes, such as climate change. This study relies on a prior-knowledge self-assessment applied to children between 10 and 13 years old, followed by a mixed analysis under the assumptions of the Grounded Theory. The goal is to understand whether children's self-perception of knowledge and interests regarding climate change can support the design of environmental education initiatives. Children declared to know about the concept of climate change and specific causes and consequences, but were generally incapable of specifying topics about which they are interested in learning about. And when these were specified, they match the ones they already know about -- sea ice changes, pollution and biota. This suggests that relying solely on children's interests may originate 'information corridors'. Future initiatives should therefore not only resonate with children's experiences and reality, but also broaden fields of knowledge by introducing innovative approaches that go beyond researchers' pre-assumptions.