Scientific language about climate used in IPCC reports is often unclear to the general public. This resource performed in-depth interviews with 20 Americans about terms used throughout IPCC climate reports. Terms “adaptation” and “abrupt change” were perceived as the easiest to understand by interviewees; “mitigation,” “carbon neutral,” and “unprecedented transition” were perceived as the most difficult to understand. However, even if a term appeared to be understood, interviewees did not always understand how it applied to climate change.