Innovations in the climate assessment development process.

Climate assessments have long been key scientific inputs that inform the development of productive and impactful climate policy in the United States and around the world. This introduction sets the stage for the suite of papers in the Topical Collection "Advancements in U.S. Climate Assessments." Inspired and informed by the release of the Fifth National Climate Assessment, the papers within this issue document lessons learned over the past 30+ years and leverage the perspectives of previous assessment authors and staff to aid those interested in developing their own climate assessments. This paper reviews the evolution of climate assessments and the factors that make for useful, usable, and used scientific products to support societal choices. Evolving user needs over the last 30+ years also reflect a shift in demand towards more localized or more context-specific climate data that integrates social science information, tools, and frameworks. To meet these needs, we highlight three areas of potential opportunity and challenge for future assessments: continued and strengthened conversations between assessment developers across geographic scale to share innovations and lessons learned in the development process; working with knowledge holders in under-represented areas of expertise to alter assessment governance and guidelines to better incorporate diverse perspectives; and seizing opportunities for using innovative communication and engagement mediums.