This current Nebraska winter does not disprove global warming, far from it. This is a historically normal winter, the only reason it's "below average" is because the average has been gradually creeping up over the past 25-30 years.
What is unusual is the lack of a "false spring" that usually hits the Great Plains sometime between mid-January and mid-February, where temperatures briefly rise to the 40's, 50's or even 60's for a few days. This gives everyone a break from artificial lighting and week-old cigarette smoke, a nice chance to stretch one's legs, take a walk through the park, get the cabin fever out of one's system before the second half of winter hits.
No such luck this year. Lincoln hasn't been above 40 since the solstice. It seems that the Jet stream (wholly unaffected by Global warming, btw.) which usually separates the Arctic from the American Midwest, is further south than usual this year.
This is important, because the plains continue unbroken to the north of here almost to the Arctic circle. Without the Jet Stream between here and there, there is nothing to prevent an "Alberta Clipper" or "Arctic Front" from blowing south from Hudson Bay, through the Dakotas, and on to here.
In a modern "normal" winter, we get one or two of these Arctic fronts a year, brining, snow, wind, and freakishly cold temps (single digits) that last for half a week. But with the jet stream to the south of us, these fronts are moving over Nebraska on a weekly basis. Just when temperatures are starting to get back to something reasonable; say, high 20's, low 30's Fahrenheit, here comes the next front.
So for you Huskers wondering what an Alaska winter is like, it's a lot like this. Anchorage is actually having an easier winter than we are since it lies on the air-moderating ocean. For all practical purposes, we are living in an interior Arctic climate right now, made somewhat better by the fact we receive ten or eleven hours of sunlight a day instead of none.
And like I said, historically, this is more or less normal, perhaps a little worse because the worst part of winter simply refuses to go away. Pioneers lived through Januaries that were even worse than this, while temperatures would usually be somewhere in the 20's by now and around 45 by the spring equinox.
So what does that tell us? That our ancestors were even more insane than we thought they were. We already knew that they settled a wasteland for no logical reason, but now that you are living through a real Nebraska winter, just consider the fact that they suffered for this, died for this, killed for this It's really too depressing to believe, isn't it?