A book classified by the CIA for more than 50 years contains a shocking theory about how the world will end. 

'The Adam and Eve Story,' written by former US Air Force employee, UFO researcher and self-acclaimed psychic Chan Thomas, was written in 1966 but its publication was halted by the agency.

It was quietly declassified in 2013, at least in part, but remained hidden in the CIA's database — until now.

In the book, Thomas claims that every 6,500 years, a major disaster on the scale of the Biblical 'Great Flood' strikes the Earth.

While experts debate the exact date of that flood in the Book of Genesis, Thomas asserts that it happened roughly 6,500 years ago, and there is some archaeological and geological evidence to support that claim. 

By that logic, Thomas argues that the next catastrophe is imminent. 

As for what the end of the world will look like, Thomas believes that Earth's magnetic field will suddenly, drastically shift, wreaking havoc across the planet. 

The reason behind the book was classified remains unclear, but some have suggested the agency was concerned the book would cause mass panic, or leak information related to secret government research. 

Thomas had connections to classified projects during his time at the defunct aerospace company McDonnell Douglas. He was part of a small team of scientists assembled by the company to investigate reports of UFOs. 

While there are no official records of Thomas working directly for the CIA, the agency's secrecy agreement means past employees need to get approval before publishing books and other works of communication. 

'In California, the mountains shake like ferns in a breeze; the mighty Pacific rears back and piles up into a mountain of water more than two miles high, then starts its race eastward,' Thomas wrote in his book.  

'In a fraction of a day all vestiges of civilization are gone, and the great cities — Los Angeles, San Francisco, Chicago, Dallas, New York — are nothing but legends,' he writes. 'Barely a stone is left where millions walked just a few hours before.' 

The first chapter, titled 'The Next Cataclysm,' starts with: 'Like Noah's 6,500 years ago... Like Adam and Eve's 11,500 years ago... This, too will come to pass...'

The cryptic opening suggests that the next cataclysm is poised to occur any day now.

The book features 55 pages, but Thomas wrote more than 200. The rest are still kept top-secret to this day. And the reason for the CIA's involvement remains a mystery.  

The apocalyptical tale begins with the destruction of California, explaining how winds 'with the force of a thousand armies' will shred everything in sight with its 'supersonic bombardment,' as the Pacific tsunami drowns Los Angeles and San Francisco 'as if they were but grains of sand.'

Thomas claims these impacts will overtake the entire North American continent 'within three hours,' as an earthquake simultaneously creates massive cracks in the ground that allow magma to rise to the surface.

But it won't just be North America that is swallowed by the destruction. 

None of the seven continents will be able to escape the onslaught, Thomas writes, with each one experiencing slightly different versions of the same dramatic end. 

By the seventh day, 'the horrendous rampage is over,' and the entire Earth has changed, he writes. 

'The Bay of Bengal basin, just east of India, is now at the North Pole. The Pacific Ocean, just west of Peru, is at the South Pole,' Thomas explains.

Even Greenland and Antarctica have been thrown toward the equator, and 'find their ice caps dissolving madly in the tropical heat.'

Thomas paints a terrifying picture of civilization-destroying climate change and tectonic rearrangement. But there is no scientific evidence to suggest that such a cataclysm is possible. 

'It's just unfortunate that these things are being put out there,' Martin Mlynczak, a senior research scientist at the NASA Langley Research Center, told The Verge.

'Extraordinary claims require extraordinary proof. And there's no proof and no science and no physics behind any of the claims about the magnetic field change being associated with climate change.' 

What's more, there is no evidence to suggest that the Earth's magnetic field ever has, or ever will, make the 90-degree flip that Thomas describes.

'That is totally bogus. If that's what happened every 6,500 years, we would certainly see it; it would be in all the records... The amount of energy to bring that about is tremendous. And you know, there's nothing to initiate it,' Mlynczak said. 

That said, Earth's magnetic poles do shift and have done so hundreds of times throughout the planet's history, according to NASA.

This phenomenon is called a 'pole reversal.' Paleomagnetic records suggest it occurs about every 300,000 years on average, though the actual time intervals vary widely.   

'During a pole reversal, the magnetic field weakens, but it doesn’t completely disappear,' NASA states.

'The magnetosphere, together with Earth’s atmosphere, continue protecting Earth from cosmic rays and charged solar particles, though there may be a small amount of particulate radiation that makes it down to Earth’s surface. 

'The magnetic field becomes jumbled, and multiple magnetic poles can emerge in unexpected places.'

But this never causes the kind of widespread devastation that Thomas described in his book.  

Even if his theory about why and how the world will end had scientific merit, there would still be reason to question his claim that the apocalypse is imminent. 

He states that the last catastrophe of this nature — Noah's Biblical flood —  happened 6,500 years ago, and that this means we're due for the next one. 

There is some geological and archaeological evidence to suggest that date may be correct. For example, a 2006 study claimed that 6,500-year-old wood recovered from the 'landing site of Noah's ark' was actually part of the ark itself. 

But the wood's age has been challenged by other experts.  

The more widely accepted date-range for the flood is between 4,000 and 5,000 years ago. If this event truly occurred during that time, then Thomas' estimated timing for the end of the world would be more than 1,000 years off.

Therefore, all the evidence suggests that the violent disaster detailed in 'The Adam and Eve Story' will not actually come to pass.