And some of them are going to extraordinary lengths to prepare for the apocalypse.

The countdown to chaos is on.

For retired defence contractor Doug Huffman, prepping for doomsday is more than just a hobby - it's all-consuming.

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"I used to kayak and ballroom dance quite a bit. But I gave all that up. Most of my time now is spent prepping. I work seven days a week, ten to fourteen hours a day. I've spent between $30,000 and $40,000 in preparation," Huffman said.

Huffman is preparing for a cataclysmic event - an economic meltdown that will lead to an apocalypse and anarchy.

His answer is to transform his Californian home for suvival - complete with greenhouse, pond and farm animals.

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On the other side of the world in Buckinghamshire England, Malcolm Bowler is going boy scout - not just preparing his home but also his palate.

"If it came to a situation where you had to feed yourself on meat, then you're definitely going to have to take an animal's life. I've eaten squirrel, rabbit, magpie. I tried once ants' eggs, which was a bit of an acquired taste," Bowler said.

Closer to home, in the Queensland town of Allora, locals have been stockpiling supplies. They believe the earth is due to collide with a mystery planet in April next year. This is their third doomsday prediction.

Scientist Dr Karl Kruszelnicki is an eternal optimist, and though he loves the doomsday hype, he just doesn't believe any of it.

"Are we doomed on the 21st of December? Yes, in the sense that there are only three shopping days left before Christmas, but no in the sense that the calendar will keep on going, the world will keep on spinning, and we're not going to be wiped out," he said.

"We will not be struck down by K-Pop or the zombie apocalypse or radioactive mutated dogs eating your guts out - none of those will happen."