The United Nations’ Intergovernmental Panel on Climate Change (IPCC) and other institutions communicate about climate change to international audiences without a background in climate science, including the general public. The effectiveness of climate change communications may be undermined by their use of complex terminology. Bruine de Bruin et al. (2021) found that Americans struggled to understand key terms from IPCC reports. Here, we examined how 24 Germans interpreted German translations of these key terms, including tipping point, unprecedented transition, carbon neutral, carbon dioxide removal from the atmosphere, adaptation, mitigation of climate change/ of greenhouse gas emissions, sustainable development, and abrupt change. We also presented these terms in the context of sentences taken from German-language IPCC reports. We identified common themes and misunderstandings. Overall, 93% of the themes arose by the 10th interview, and no new themes arose after the 18th interview. While interviewees initially rated most terms as easy to understand, both climate-concerned and climate-ambivalent interviewees were unfamiliar with some terms or combinations of terms, unsure of the link to climate change, and confused about details. Some also expressed mistrust. Moreover, all sentences were perceived as too long and complex. We discuss the implications of these findings for climate change communications.