I'm really not sold out either way on this whole debate for two reasons.
1. I can't seem to find original data for all these claims (and if anyone has any please point me to it). I really don't like taking someone's word for it when the trends they're talking about should be simple enough to be observed by an untrained eye.
2. Global scale is a very difficult thing to deal with because proving cause is almost impossible. We genuinely haven't been recording this stuff that long, and we essentially end up with hypothesis of cause and effect rather than any real conclusion. From what I've heard it sounds like this is cause and effect, but again, without the original data, what kind of change are we really talking about here?