When most reputable scientists concerned with the issue say that the world is warming due to mankind's actions, I don't argue with them. Since every winter has snow days and warm days, I would expect that even during an overall warming trend, there will be unusually cold and snowy days, just not as many now as, say, 20 years ago. Cherry-picking the odd snowy day is a method of "reasoning" that seems to appeal to right-wing anti-state nutbars, but hasn't convinced any groundswell of qualified scientists to change their opinion as far as I'm aware.