I hope that this explains it. Please don't make the same silly mistake again. It is an easy trap to fall in to. "Well, climate has been changing since the beginning of time!". Not this fast it hasn't. And, to reiterate, there is no natural cause or combination of causes that could do it. None. Nada.
  "silly mistake" Really Jeff?
I think YOU'RE the one making the silly mistake. How do you know how fast the climate changed millions of years ago? How do you know that a faster changing (if it really is) climate isn't part of the cycle? Just because it might be changing faster, or maybe we're just paying closer attention, doesn't mean it's man's fault.
No natural cause that could do that, are you sure?
One natural cause I can think of that happened last year, and we've had screwy weather ever since, was the earthquake & tsunami in Japan, that tipped the earth 3ยบ on it's axis, you don't think that might just have something to do with the strange weather we've had all this year? I do think it's strange that all the brilliant scientists never had too much to say about that one way or another, unless it's because somehow it might disprove one of their theories.
Man cannot change the climate for better or worse and it is beyond arrogant to think that man has such powers.