Mike Baillie was trying to match those sulfate spikes in the ice cores to tree ring series and had some luck with it.
Yes thanks. To advocate the volcanolgists view though, the papers only confirm a relationship with peak sulfate distribution, not the cause of it. In the absence of confirmation of the eruption or eruptions that actually emitted such high loads, and importantly with sufficient stratospheric injection, other possibilities need to be considered before the rhetoric becomes, well... absolutist (of a fashion). Did temps lead to aridity and widespread and prolongued peat burning, therein providing the feedback? Lots of peat in the Tropics.
I'm open to suggestion, but only closed by a perfect equation from source to effect. If it doesn't happen in my lifetime then that's a shame.