I don't think it's the greenhouse/global warming, as much as, it's just a natural cycle the Earth goes through every 11 million years or so! Winters in Denver Colorado ain't anything like they used to be here when I was growing up...We have had a couple of big dumping snows in the early spring a few years back, they were melted off within a week, but, the "Blizzard of '82" is still talked about....sub zero temps & much snow for well into a month or so, my '66 Chevelle sat stuck in a neighbors front yard for a month after the snow stopped that year! Brrrrr!