Global warming had long been discussed as an abstract matter of physics and chemistry. Only in the 1990s did the more tangible costs caused by natural catastrophes come into focus. The key corporate actors to advance this damage and risk perspective on climate change and corroborate it with data – reinsurance companies – have largely been overlooked in the literature. Drawing on expert interviews, hitherto confidential archival sources and text analysis, this paper traces how the two largest reinsurers have made sense of climate change and become important voices in creating awareness of man-made climate change. It underscores their unique role as both producers and translators of climate change knowledge and highlights the thorny and even subjective nature of interpreting climate-related data. This sheds new light on the history of climate change knowledge and raises important questions about the role of business actors.