FIGURE 1.2 The yearly averaged sunspot number for a period of 400 years (1610-2010). The Maunder Minimum
is shown during the second half of the 16th century. SOURCE: Courtesy of NASA Marshall Space Flight Center.
influences. The IPCC Fourth Assessment 23 and the recent National Research Council report on climate
choices 24 agree that there is no substantive scientific evidence that solar variability is the cause of climate
change in the last 50 years. 25 However, the mechanisms by which solar variations can affect climate over
longer timescales remain an open area of research.
THIS WORKSHOP REPORT
Chapter 2 of this report summarizes the workshop presentations, ordered according to broad
science topics. Chapter 3 summarizes the panel discussion session. Appendix A contains the statement
of task and work plan for the project. The full workshop agenda is included in Appendix B, and
workshop presentation abstracts, prepared by the workshop speakers, are included in Appendix C.
This report summarizes the views expressed by individual workshop participants. Although the
committee is responsible for the overall quality and accuracy of the report as a record of what transpired
at the workshop, the views contained in the report are not necessarily those of all workshop participants,
the committee, or the National Research Council.
23 S. Solomon et al., Technical Summary in Climate Change 2007: The Physical Science Basis. Contribution of
Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change , 2007
24 National Research Council, America's Climate Choices , 2011.
25 National Research Council, Advancing the Science of Climate Change , 2010.