Does the cold snap disprove global warming? Well, considering this cold "snap" has lasted for, oh, the last few years, I'd have to say it does.
Of course, you've also got the global warming fanatics who take everything no matter how contradictory and say it proves global warming: cold snaps, heat waves, glaciers melting, glaciers growing, more hurricanes, less hurricanes, etc. And if you don't agree, well, then that means you're just ignorant of science.
A synonym for such people is also "assholes."