Summary
The committee reviewed the draft Synthesis and Assessment Product (SAP) 3.2, focusing on the extent to which the draft document meets the requirements set forth in the prospectus. The current draft was clearly written for an audience of researchers involved in assessment efforts. The product provides initial information regarding the influence of short-lived radiatively active species on future climate and has shown that these short lived species are significant in forcing climate. However, the current draft needs revision to make the document easier to read even by subject experts. Many of the figures and captions do not convey the information intended and comparison of figures is difficult because different scales are employed. In addition, the document needs to distinguish between the types of models, especially for the benefit of non-specialists. Also, in the technical sections of the report, more details about the models used and statistical methods employed need to be included (see specific chapter reviews).
Although the assessments community should find this document extremely helpful, understanding the impact of short-lived species on future climate 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 3.2 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.” Chapter 3 does not 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 the effect of short-lived species on climate.
