"We do not have to step over the edge of the abyss into darkness and destruction," Hancock says, calling this point in time a "cusp moment."
"It's up to us. It's totally up to us."
Morandir Armson, the Australian scholar, says the belief that 2012 marks a positive shift is one also shared by UFO groups, such as the Ashtar Command and the Ground Crew. These groups have no headquarters but for internet sites.
He says they refer to themselves as "lightworkers" who believe a fleet of alien space ships hover around our solar system.
"By doing good works on earth [they believe] you can speed up the consciousness of our humanity," says Armson.
In many ways, they emphasise the more positive aspects of the traditional Christian Apocalypse. The fire-and-brimstone part gets downplayed in favour of the glorious Kingdom to come.
Some 20% of Americans believe we are in the end times, and that they will see the return of Jesus Christ in their lifetime.
This month marks Advent in the Christian Calendar, during which Christians are encouraged to read from the Book of Revelation, the apocalyptic vision of St John the Divine.
"It's full of gory and grotesque detail of how the wicked are going to be punished," says Ted Harrison, author of Apocalypse When: Why We Want to Believe there Will Be No Tomorrow.
The twenty-first of December, however, is not on the biblical calendar and few, if any, believers in the traditional Book of Revelation are attached to this date.
The supposed date of the coming apocolypse, 21 December, also marks the Winter Solstice, symbolic in many cultures of the end of darkness and the renewal of the light.
It might, suggests Harrison, focus our minds on how we have been treating the planet and those on it, and how we could mend our ways.
In this respect, he says, "It might become a self-fulfilling prophecy. That's one hope. A remote one, but it is one hope."