Dinobot had it right about his own death:

http://www.youtube.com/watch?v=Oifs6ulpd9A

I know I'm really reaching back here, but I remember that movie driving me nuts during the "freezing" scenes. If air from the upper troposphere/lower stratosphere descended to the surface, it would descend at the dry adiabatic lapse rate, which is ~10 degrees C per km of height. The top of the troposphere is ~10 km above the surface and the temperature is around -60degrees C. This means that air that descended from there (assuming its dry) would compress and warm adiabatically to +40 degrees C by the time it reached the surface. People would be suffering from heat stroke rather than freezing.

These aren't traditional clouds that you see in the troposphere (lowest layer of the atmosphere). To get an ozone hole, you need VERY cold temperatures. This happens after during polar night when there is no sunlight for about half the year. The stratosphere is so cold that it can form ice crystals that contain nitric acid. These crystals act as surfaces where ozone destruction takes place. Once the sun rises at the pole (March equinox for the northern hemisphere), the UV light "splits" compounds like CFCs into reactive materials such as Chlorine. The ozone destruction reaction still will not work efficiently without the initial nitric acid/ice crystal surfaces. This is why we don't often see this happening in the Arctic, while the Antarctic shows this signal annually.

http://www.noaa.gov/features/02_monitoring/arctic_thinning.html

The "coldness" of the pole is related to the strength of the winds (polar vortex) around the pole in the atmosphere. The south pole generally has strong winds circling it, which works to cut off the south pole's atmosphere from the rest of the world, especially during the southern hemisphere winter. Part of the reason for a stronger vortex is due to ocean surrounding the south pole on all sides, with land masses far away. In addition, the southern hemisphere in general has more ocean compared to land than the northern hemisphere.

In the northern hemisphere, the polar vortex generally has more waves or pertubations in the polar vortex, which help to mix in air from lower latitudes. Some of this is caused by planetary waves that propagate vertically in the atmosphere. These planetary waves are formed generally due to land masses and mountains affecting the atmospheric flow (not this simple but this is the general idea). Generally, the factor that causes the difference in the north and south polar vortices is land mass.

Now relating this all to climate is a bit tricky. It has been seen that as the troposphere warms (lowest layer of the atmosphere), the stratosphere cools. This has been seen in observations in the last 30-50 years (you may argue that 50 years might not be enough to define a long-term trend). The reason for this cooling is basically radiative balance (though I'm oversimplifying it here). If the troposphere warms due to increased greenhouse gasses, then the atmosphere above must cool above it. There cannot be more heat coming in than is leaving the Earth. A good analog to this is Venus. Venus has huge concentrations of greenhouse gasses. We know its surface is very hot (over 400 degrees C), while its upper atmosphere is much cooler than Earth's (gets down below -110 degrees C, compared to about -80 C on Earth).

The tough part is separating the stratospheric cooling due to greenhouse gasses and ozone destruction from CFCs (although we may know this answer once all the CFCs are out of the atmosphere in the future). Increased greenhouse gasses will warm the troposphere and cool the stratosphere. This will lead to more polar stratospheric clouds, leading to more reactions sites for ozone destruction. More ozone destruction means less UV light is absorbed by ozone in the stratosphere. Less UV absorption means a cooler stratosphere which further intensifies the problem.

My building in DC was evacuated after this. It was actually powerful enough to knock a TV off the all and a few plant pots onto the ground. To be honest, when it struck I couldn't help but think terrorist attack before earthquake crossed my mind.