I think that perhaps one of the greatest challenges in this whole issue is the temptation to lay the blame for climate change on a single factor, and isolate that one factor as the cause of it all. This is something that has tended to occur in my own field as well, so it was relatively easy to recognize.
If this suggestion about sulfur dioxide has merit, and it may have, then we should approach it with solutions instead of bickering about which single element is more important. Note that the role of CO2 was not dismissed, but acknowledged as having a "driving" influence, presumably a significant influence. The synergistic effect of these two factors, and undoubtedly more, should be examined, and addressed with comprehensive solutions (if possible at this late date) in mind.
Just as in my own field, where there is no single right, all-encompassing answer for many of the phenomena we study, but several contributing factors, I'm not possessive of a single line of thought here. I want to know what the truth is so that we can, hopefully, undertake the most effective steps to deal with it.