The Extreme Ice Survey (EIS) is an exemplary case for examining how to effectively communicate scientific knowledge about climate change to the general public. Using textual and semiotic analysis, this article analyzes how EIS uses photography to produce demonstrative evidence of glacial retreat which, in turn, anchors a transmedia narrative about climate change. As both scientific and visual evidence, photographs have forensic value because they work within a process and narrative of witnessing. Therefore, we argue that the combination of photographic evidence with transmedia storytelling offers an effective approach for future scientific and environmental communication.