The facts say that globo-warmthers are crazier and more delusional than the worst religious fanatics of the Medieval Church.
Satellites demonstrate that temperatures have been evenly dropping over the entire planet for thirty years. This is all before the sun has one massive flux maximum remaining in 2012 and then cools to unprecedented levels, virtually "snuffing out" as one NASA researcher has predicted.
Some scientists have theorized that the Sun "flutters" like a candle as it approaches a cyclic flip-flop, with great gusts in the form of solar flares, before it then ebbs for a long time, perhaps 11,500 years or even longer until the Ice Age once again gives way to the warmth of the interglacial. This cyclic behaviour probably reflects something to do with the interplay of gravity and mass, magnetic fields and the original layered composition of the sun's fuel as it burns. The ultimate governor is likely our passage through the galactic plane and the angle at which force is exerted by the mass and magnetic fields it carries.
We don't know what is going to happen in 2012 or what will be happening in tandem with whatever takes place in 2012. We expect that whatever miseries mankind is enduring at that time are going to be amplified a thousandfold by what takes place in the natural world in the year 2012 when it gets here.