It seems like we've had more of both extremes. We've had hotter summers, with many of them having entire months over 100o daily highs. And we've had really cold winters too, maybe even more snow in the last five years than normal. I can remember some record cold winters in the 70's, with some record snowfalls and ice storms. So I know what you mean. But we've had some pretty cold ones in recent years too. I think that we're seeing more at each end of the spectrum.That tells me we might be entering a macro-cycle-weather thing. If we are, I'm not sure that I think pollution is doing it, although it might be. I'm not privvy to the data, haven't paid attention to the seasonal averages. I also don't trust the things said by those with political agendas on either side, so I'm skeptical of any information that is proferred in this regard.
What I know is that long before ecologists sounded their warnings and global warning scares, geologists have found evidence of what they thought were regular climate shifts. So it would seem that this kind of thing happened before man was burning stuff. On the other hand, it would seem prudent to use fuels that pollute less and maybe don't require us to buy oil from potential enemies. So I'm all for advances in that area.
I like my ground-pounding big-block, and I'm proud that the exhaust will burn your eyes so bad you can't see. Stand near it when it's idling and your eyes are burning in about 30 seconds. That's a hot-rod and the kid in me loves that stuff. But I wouldn't have any problem filling it up with alcohol though, and then it would be cleaner and wouldn't burn your eyes anymore.
Anyway, not that you asked for my opinion on the greenhouse gas thing, but out it came anyway. I respect both sides of the global warming debate, as long as their not screaming. The screamers on both sides annoy me. As for weather shifts, I think we're a little hotter here in the summer and a little cooler in the winter but it isn't a huge difference and I definitely don't think we'll become extinct as a result.