Is the world really coming to an end in 2012 like it does in the new sci-fi movie 2012? There are actually millions worldwide who really believe the end is near and they are preparing for the apocalypse right now.

"We could lose up to 2/3's of the population, maybe 200 million could perish," says Dennis McClung. He says he doesn't believe the world will actually end, but he does believe apocalyptic events will occur in 2012, December 21, 2012 to be exact, because that's when the Mayan calendar ends.

The Maya are an ancient Central American civilization which at the zenith of its power was regarded as pretty sophisticated, especially in science.  

McClung believes so much in the ominous meaning of the Mayan calendar's end, he runs an online business from his home in Phoenix called 2012Supplies.com, which sells supplies to people all over the world who are preparing for doomsday.

"My top sellers would be water purification tablets. You can only go three days without water. Followed by 72-hour kits which are very important, [it's] everything you need basically for three days," he says.

McClung also sells a full-body suit and gas mask which he says protects against a nuclear, biological, or chemical attack. "You name it, this [suit] will protect you from it." It even comes in different sizes to fit children.

Before you start worrying, there have been other famous dates when the world was supposed to end, like the Y2K scare on January 1, 2000. There were apocalyptic predictions of chaos in the streets and the breakdown of society as we know it, but the world is still here.

Gary Baddeley explored the 2012 doomsday phenomenon in the documentary 2012: Science or Superstition. Besides the Mayan calendar theory, Baddeley says scientists are predicting an increase in solar activity in 2012, which could emit a dangerous amount of radiation at the Earth.

Baddeley says, "That radiation could hit us so hard that it knocks out all of our satellites, that it disrupts all of our electronic communications, it could also cause a number of meteorological conditions here on Earth; tidal waves, tsunamis."

But Donald Yeomans, manager of NASA's Asteroid Division, reassured everyone that we're still going to be around after 2012. "Extraordinary claims require extraordinary evidence and in terms of all the effects that have been predicted for 2012 there's not one bit of credible evidence."

And what does the star of 2012, actor John Cusack, think? He tells INSIDE EDITION, "I was always into some of that stuff, Nostradamus and the Mayans...No, I don't think [the world] is going to end in 2012."