I really should word that better in the future. My revised claim is that, " Among papers expressing a position on AGW, an overwhelming percentage (97.2% based on self-ratings, 97.1% based on abstract ratings) endorses the scientific consensus on AGW." That is very, very significant.

You shouldn't be confused by the number of papers that express no position. They do so because human influence was not the focus of their study, thus they cannot make a claim about it. Such papers are likely showing the trends from measured data, but not studies themselves on the human impact. Again, do not confuse papers not taking a position as papers taking a neutral position. Those are completely different things. Also don't assume that because many authors have not had their name on a paper taking a position they do not have one themselves. They simply haven't done research specifically on human impact. Scientific literature isn't a place to air out their opinions, it is a place to present and analyze their data. The data, as argued by 97% of peer reviewed journal articles on the issue, agree that humans are to blame.