The few meteorologists I know do not believe global warming has anything to do with human activity. In fact a couple of them seem to think we're in for a prolonged period of cooling.
If this were only happening in North America, it might be an indicator. But it's happening in Europe and Asia, too.
Sam Answers The Question
Imagine my surprise (not) when Sam Champion, ABC's Good Morning America meteorologist, answered Diana Sawyer's question during her evening news broadcast about the effects of global warming on the unusually cold weather we've been experiencing. When asked if those below normal temperatures and above normal snowfalls might be attributed to global warming, Sam answered (as best I can remember):