The Climate Science Special Report and NCA4

CSSR Executive Summary Cover

The cover of the Climate Science Special Report PDF.

On November 3, 2017, the U.S. Global Change Research Program (USGCRP) released The Climate Science Special Report (CSSR), a detailed assessment of our current understanding of the Earth’s climate system, with a primary focus on the United States. The report is available in both HTML and PDF format at

The Climate Science Special Report serves as Volume I of the federally mandated Fourth National Climate Assessment (NCA4) and is intended to provide the authors of the forthcoming Volume II of NCA4 with a comprehensive, up to date scientific foundation for assessing the impacts and risks associated with climate change.

The report includes detailed information on the physical drivers of the climate system and observed and projected changes in temperature, precipitation, extreme events, ocean chemistry, land and sea ice, land cover, and sea level. It also includes chapters on potential surprises and climate change mitigation.   

Working as part of NOAA’s Assessments Technical Support Unit (TSU), scientists and other experts from CICS-NC played key roles in the development and production of the CSSR:

  • Several institute scientists served as lead authors on the report, and the entire TSU science team made significant contributions to many of the figures showing observed and projected changes in key aspects of the climate system.
  • Communications experts served as technical editors, helped develop scientific figures and infographics, and designed the layout of the PDF version of the report.
  • Web developers and software engineers designed and built the interactive CSSR website, which allows users to read content, view figures, and share findings on social media. The same team also built the author collaboration tools used to manage figures and facilitate communication among the various chapter teams.
  • Data experts helped ensure openness and transparency by facilitating and supervising the collection and delivery of metadata for all the figures in the CSSR.

This work builds on contributions to previous USGCRP reports, including the Third National Climate Assessment released in 2014 and the Climate and Health Assessment released in 2016.

Looking Ahead

In addition to working on the CSSR, the TSU team has been busy helping develop drafts of NCA4 Volume II: Climate Change Impacts, Risks, and Adaptation in the United States. In conjunction with the release of the CSSR, a draft of NCA4 Volume II was made available for public comment and peer review by the National Academies of Science. The team will be hard at work throughout 2018 finalizing NCA4, with an expected release in December 2018. 


Screenshot of the top banner of the Climate Science Special Report website.

The Climate Science Special Report website provides a convenient and attractive interface for accessing the report’s text, figures, metadata, and references.