Analysis of nature-related themes and terminology in U.S. climate assessments

Abstract “Nature” is a broad term with neither a standard definition nor consistent use, even across federal reports like the National Climate Assessment (NCA). The process of defining complex topics like “nature” is difficult given the broad range in people’s understandings of and relationships with the natural world. To support the development of future nature assessments and NCAs, we analyzed use of nature-related words and themes over time in all five published NCAs and one preliminary draft of NCA5. Overall, despite the prevalence of nature-related topics, we found the term “nature” was not used as much as others like “ecosystems,” though “nature-based solutions” appeared more in the latest NCA (NCA5) compared to earlier NCAs. Additionally, the scope of nature-related chapters in NCAs has evolved from initially focusing on impacts of climate change on ecosystems and ecosystem services towards highlighting solutions that nature can provide and implications for human well-being and environmental justice. We suggest improving the consistency of nature-related terms and topics within future climate and nature assessments to help promote dialogues across disciplines, reports, and assessment chapters, allowing researchers to better tackle multifaceted issues of global change. However, broad standardization of nature-related language may unnecessarily constrict the diverse understandings of nature. Definitions of nature-related terms should be revisited and adapted based on changing views and realities as global changes evolve.