Bailout talks implode, leaving economy’s fate unresolved, Chavez reaffirms Russia alliance during visit, Pirates seize ship carrying tanks, ammo. Just click over to CNN.com or any other news site and you’ll see why post-apocalyptic and doomsday movies seem more relevant than ever. 

The doomsday scenarios in movies can be pretty outlandish, but some of them are actually plausible. After all, in world where pirates have tanks, Hollywood doesn’t need to stray far from reality for a good yarn.

Below the jump, we put five doomsday movie scenarios to the plausibility test. If you’ve always secretly thought Waterworld was a work of dead-on global warming prophecy, read on.

5. Waterworld

The doomsday scenario:

Global warming causes the complete melt of glaciers and polar ice caps, flooding nearly the entire planet.

Could it really happen?

No. Make no mistake, rising sea levels due to climate change are very likely to cause major problems in the the next century, but a near-total covering of the world in water is not possible. While the melting polar ice caps are destroying the habitat of the polar bear, it’s important to remember that most of the Northern ice cap is already floating in the ocean, so its contribution to sea level rise will not be as severe as Greenland or Antarctica. And even if all the ice melted off of those two land masses, the collective sea level rise would be about 67 meters, or 220 feet. That’s very bad news if you live in Amsterdam or New Orleans, but it’s certainly not enough to cover all but the highest mountains, as in the film. We also shouldn’t expect those chucks of ice to melt too fast. It will likely take a thousand years or more for them to be gone completely, so we’ll have plenty of time to hoard paper and build cool boats, or just move to Denver.

3. Blindness

The doomsday scenario:

The entire population except for one woman goes blind almost instantly. Mass hysteria breaks out, quarantines are ineffective, the strong and brutal hoard food and commit atrocities.

Could it really happen?

Maybe. There is a form of infectious blindness, caused by the bacterium Chlamydia trachomatis. It’s usually passed physically, through towels or by touching an infected person’s eyes. It’s most common among children in poor areas where hygiene is lacking. The up side is that it takes a while, unlike the mysterious plague in Blindness. The down side is that blindness caused by trachoma is extremely painful, as the eyelids turn inwards, scratching the surface of the eye to the point where it’s no longer transparent. In its current state, Chlamydia trachomatis could not cause instant mass blindness, but if by some fluke the bacteria became exponentially more contagious, we could be in for a dark future.

2. Children of Men

The doomsday scenario:

Mass infertility. In the film the cause is unknown. Not only are women unable to get pregnant, pregnancies in progress also fail when the mysterious event occurs.

Could it really happen?

Maybe. In the landmark 1995 book Our Stolen Future, the authors examine how chemical pollutants effect reproductive health. In short, there are an increasing number of chemicals floating around that mimic hormones. These have been shown to cause all sorts of problems including reduced puberty age, fetal defects, and reduced sperm counts. The kicker is that many of these chemicals are extremely persistent, meaning that they do not break down. So even if the junk leaching out of your Nalgene bottle is very slight, it will join the other hormone disruptors lodged in your fat cells until they gather enough friends to do some real damage, even if it takes several generations. This differs from the film in that it’s likely to be far more gradual. A steady decline in global sperm count wouldn’t effect pregnancies in progress, and we’d see it coming.

1. Armageddon

The doomsday scenario:

A huge asteroid strikes Earth, wiping out every living thing.

Could it really happen?

Yes. It nearly happened 65 million years ago, causing the extinction of most dinosaur species, and it could happen again. More recently, a meteor or comet exploded over a remote region of Siberia in 1908, detonating with the force of 1,000 Hiroshima bombs, knocking over trees in an 830 square mile area, and on the scheme of things, that was a small one. The US government and the UN have recently begun to take the threat of asteroid collision more seriously, but that doesn’t mean we’re prepared. Many experts put this scenario at the top of their list of likely causes of human extinction. There have been several near-misses, some quite recently. As far as we know, the rock that most likely has our name on it is (29075) 1950 DA, which could spin through space in one of two ways: if it picks door number 1, it will miss us by millions of miles, if it picks door number 2, it will have a 1 in 300 chance of ruining everyones’ day. Luckily, that day won’t come until March 16, 2880.

In the meantime, we can work out a reliable way to either destroy the asteroid, as they did in Armageddon, or alter its course and eliminate the threat. The latter solution is looking more reasonable at the moment, but it’s no surprise Michael Bay preferred interstellar nuclear weapons to a film about altering an asteroid’s course by a fraction of a degree using the gravitational pull of an unmanned spacecraft. The really scary part, however, is that while about 800 near-Earth objects larger than 1 km across (the really bad ones) have been accounted for, many estimate that about 200 have yet to be found. Let’s just hope they find the one heading for us in time to get Bruce Willis and his team from their offshore oil rig and into a nuke-laden space shuttle.