Although the assessments community should find this document extremely helpful, understanding the present level of scientific confidence and remaining uncertainties in identifying and describing how the climate system has varied over approximately the last half-century is critical and should be explained to all stakeholders of climate change science as outlined in the SAP prospectus. In this sense, the current draft of SAP 1.3 falls short of the requirements set forth in the prospectus. The draft does not address all of the specified audiences, particularly “policymakers, decision-makers, and members of the media and general public with an interest in developing a fundamental understanding of the issue.” Chapters 2 and 3 do not necessarily describe the state-of-the-science, the problems in methodology adopted in the current models, and the most uncertain factors in the current research regarding reanalysis and attribution. Much of the data in the product is original research. The authors should explicitly distinguish the findings from the peer-reviewed literature from those derived from original work. The report should give precedence to peer-reviewed literature whenever possible.