It's never happened before either, right? These are the facts that our "global warming experts" like Al Gore etc try to shove under the rug, and in fact many "global warming" experts have made moves to try to have these facts struck from the record, because it makes their arguments much more weak. I'm sure industrialized society caused the mini ice age too, or rather, the global warming trend that came BEFORE that. The warming trend then was even more pronounced than it is today... But it MUST be people causing it right? Can't be any way that it's a natural process.
http://en.wikipedia.org/wiki/Medieval_climate_optimum
http://www.ncdc.noaa.gov/paleo/globa.../medieval.html