Several authors claim that a major, world-changing event will take place in 2012.
Books written on the subject of 2012:
The 1995 book The Mayan Prophecies linked the Maya calendar with long-period sunspot cycles.
The book 2012: Mayan Year of Destiny claims the Maya may have been instructed in their wisdom by discarnate entities from Orion and the Pleiades. Contact was maintained through shamanic rituals conducted in accordance with the movements of planets and stars.
The 1997 book, The Bible Code claims that, according to certain algorithms of the Bible code, a meteor, asteroid or comet will collide with the Earth.
The Nostradamus Code speaks of a series of natural disasters caused by a comet (as above) which will allow the third anti-christ to disperse his troops around the globe under the guise of aid in preparation for a nuclear war.
The Orion Prophecy claims that the Earth's magnetic field will reverse.
Terence McKenna's mathematical theory predicts a point of singularity in which humankind will go through a great shift in consciousness.
The Prophecy of the Popes, attributed to Saint Malachy, speculated that Pope Benedict XVI would reign during the beginning of the tribulation of which Jesus spoke, and sometime later a future pope described in the prophecy as "Peter the Roman", the last in this prophetic list, would appear, bringing as a result the destruction of the city of Rome and the Last Judgement.
Many new age spiritualists and philosophers ("new-agers") believe humankind will enter an age of enlightenment in 2012. There are a range of varying, generally positive, beliefs shared by a subset of spiritualists from the mundane to exceptional, including a positive social shift and age of peace, mankind becoming psychic and connected by a collective, or an evolution of the human race into non-corporeal beings made of "spiritual" energy, or light energy. An alternative view is that we are already thought-forms and will be realizing our true selves in this year.
Some UFO / extraterrestrial enthusiasts, along with some new-agers, believe 2012 to correspond approximately with the return of alien "watchers" or "caretakers" who might have helped the first human civilizations with developing their technology and may have been waiting for us to reach a higher level of technological or social advancement. Beliefs range from the extraterrestrials having benevolent purposes, such as to help human society evolve, to malevolent purposes, such as enslavement of mankind.
In 1976, Zecharia Sitchin stirred up a great deal of controversy with the publication of his book, The Twelfth Planet. Nibiru also known as Planet X or The Twelfth Planet is said to be quickly nearing the Earth right now and could cause global devastation. Most historians, anthropologists and archaeologists consider it all Sumerian myth, of course. But Sitchin's work has created a die hard group of believers and researchers that say the return of Nibiru is close at hand - possibly around 2012?