Make it stop!!! Okay, this wasn't as mind-numbing as "Alexander", and I did see it only on cable...but the whole time I was watching it I felt uncomfortable, as if I was looking at a really bad multiple-vehicle collision with lots of injuries. You know you shouldn't, but some morbid part of you won't let you turn away...
As for the plot...Global Warming can lead to another Ice Age. This is bad enough, like saying that setting fire to your house will help to keep your beer cold, but in this movie the Ice Age takes only fifteen or twenty minutes to get started. You no sooner set a match to the gasoline-soaked drapes than the entire house is encased in ice. Oh yes, and you are being hunted by wolves who escaped from the city zoo. These are the only animals that escaped from the zoo, and as the snow got deeper and the temperatures lower, they didn't have the sense to head South while they could.
I really doubt that there could be such a thing as the snow super-hurricanes as depicted in the movie, but these were the chosen special-effects-ex-machina to jump start the glaciers. A hurricane is a heat engine, driven by the accumulated warmth of the sun on tropical waters. What drives a super-snowcane? The answer to that one is easy: A bad writer's overheated imagination. We get not one, but three of these things, all appearing overnight and sweeping down from the North Pole simultaneously. The one that hits New York also generates a storm surge.
A real hurricane's storm surge is a dome of water under the eye of the storm. It's there because the air pressure in the eye is much lower than anywhere else. A storm surge might go eight to ten feet for a big hurricane. The super-snowcane generates a surge high enough to slap the face of the Statue of Liberty and submerge Manhattan. It comes in from the east (The supercane winds would be pushing all the water the other way) and arrives several minutes...sorry, hours...or maybe days...before the eye of the storm does. The pacing in this movie is astonishing whenever it isn't simply unbelievable. I think the passage of time was sped up in order to cram as many really cool, nay, chillin', special effects into two hours as possible.
The storm surge then does not leave. No, it stays in Manhattan, enjoying Times Square, the Guggenheim and all the other cultural attractions for a while. Gravity cannot pull it away, or perhaps the ecology is so unsettled that water can no longer flow downhill. A Russian supertanker joins in as another sightseer and then it all freezes solid. Sea water can apparently freeze in minutes.
The New York supercane is monitored from space. The other two, ravaging Europe and Siberia, are apparently less interesting. At one point, we are told that the temperatures at the eye of the supercane are dropping by ten degrees per second. Now, it doesn't matter if the degrees are Fahrenheit or Centigrade. In less than a minute, this storm will be freezing the air itself solid, but this doesn't happen. Apparently the CGI budget could only go so far.
This unprecedented disaster forces the evacuation of the entire US. No mention is made of what happened to the Canadians. In fact, I don't think any mention at all is made of the Canadians. Maybe to them it was just a chilly Spring, eh? Mexico, on the other hand, is mentioned a couple of times, since all 300 million Americans seem to be trying to get there. Just how they get there is as unmentioned as the Canadians, since early on we are told that neither planes nor trains can operate in the weather. Could SUVs?
At the end of the movie, we are treated to a sermon about how We Should Respect Nature More, and Not Exploit Our Precious Resources. There's also a humble obesiance to all the Third World countries who so charitably took us all in. Got that? The US has been destroyed by its own arrogance, and maybe now we'll appreciate subsistence farming and outdoor plumbing a lot more.
The special effects were impressive, but they followed each other so quickly and bewilderingly that it was a lot like being punched repeatedly in the head by Mike Tyson. Some of the special effects shots were views from a space station. At the end of the movie, we see that this was an Ice Age to top all Ice Ages. The snow and glaciers reach all the way down to the Rio Grande. They stop there, though. Apparently Mexico wouldn't let them in. But...During the last Ice Age, which only reached as far South as Chicago, the sea level was a couple of hundred feet lower than it is today. In spite of glaciers now occupying Phoenix, San Diego and Orlando, in THIS movie, the sea level hasn't changed at all and the coastlines are exactly the same as they were the day before yesterday.