Are there any scientific facts supporting the coming horrific events leading up to Dec 21 2012?

Well, the legend of the end of the world in 2012 is based on the Mayan calendar. According to this calendar, the date of the world's formation is 0 baktun 0 katun 0 tun and 0 winal (these are measurements of time), which is in our calendar 3114. August our 11 B.C, and it is over in 12 baktun 19 katun 19 tun and 17 winal, which is exactly on 2012. 20th of December. By this, the "end of the world" is on December 21. 2012., which is not the end of the world, but a start of another "world". The legend may strengthen by the date of this:

2012.20.12.(YYYY.DD.MM.)