A supervolcano disaster may sound like a third-grade science project that's gone awry, spewing baking soda-based lava onto the teacher's desk, or like something out of a cheesy sci-fi B-movie. However, supervolcanoes are very real, and the results of one erupting would be far more disastrous than baking soda or bad ratings.

Take the supervolcano percolating in Wyoming's Yellowstone National Park, for example. This restless giant could erupt volcanic ash, lava and hot steam without much warning. It would spread destruction from Wyoming to the Gulf of Mexico, prompt significant weather changes across the planet and kill everything within reach of its miles-wide lava path [source: Cessna]. Even the magma of the smallest erupting supervolcanoes could cover some 240 cubic miles (1,000 cubic kilometers) [source: McGuire]. This makes a large supervolcano, like the one in Yellowstone that measures 25 by 37 miles (40 by 60 kilometers), a super threat [source: Handwerk]. And there are five other supervolcanoes around the world, each sufficiently powerful to threaten global extinction.

Toward the end of it's life, the Earth's sun will begin expanding like so many Americans' waistlines. But the fact that the sun will need to let out its figurative belt as it ages isn't unusual.

As stars like the sun near the end of their natural lifespans and become first red giants and then planetary nebulae, they expand massively, overtaking planets that happen to be nearby. This means that the Earth should eventually be pulled into the sun's dying embrace, unless the sun's decreased gravity enlarges Earth's orbit and allows our planet to escape [source: Cain].

Either way, don't worry about your progeny spiraling into the sun. The star's expanding range of heat and radiation will kill humanity (and evaporate the oceans, and melt the planet's crust) long before it encompasses the Earth. And there's one more bright side to this scenario: The Earth/sun death course isn't expected to take place for another few billion years or so [source: Wagenseil]. That's plenty of time for a different apocalyptic scenario to play out.

In this image of a dying sunlike star, clouds of escaping gas are lit up by the star's radiation. In the 18th century, astronomers thought such heavenly bodies might be planets and named them planetary nebulae.

We admit that an end-of-the-world plot that centers on chunk of space rock plummeting to Earth is a bit overdone. Or so it seemed, until we figured out that this sort of scenario could actually happen in the not-too-distant future.

Scientists have discovered an asteroid that's a quarter-mile (390 meters) in diameter and may hit the Earth in 2036. If it does, it would explode upon impact with more than 100,000 times the force of a nuclear blast, releasing planet-darkening dust into the atmosphere and endangering every life-form on the planet [source: Jha].

Plus, scientists report that even larger bodies lurk in a strike zone near the Earth, some of which are large enough to decimate entire nations on impact - if their course interferes with ours [source: CNN]. Like the 2036 asteroid, these may need to be dispatched using spacecraft set on a collision course. Sounds like a box-office winner to us.

Asteroid impacts are only boring until they happen to you.

Since 2006, honeybees have been dying by the millions. To date, experts still aren't sure what has been causing up to 90 percent of hives to suddenly die, a parasite is to blame. Why does it matter that such a small creature isn't buzzing about in as large numbers as before?

Bees offer billions of dollars of free labor every year as they pollinate agricultural crops. According to the U.S. Department of Agriculture, one-third of what we eat comes from plants that were pollinated by bees [source: USDA]. And that doesn't even factor in statistics about those who eat red meat. Cattle and sheep that are fed pollinated roughage, like alfalfa, rely on bees, too. The same goes for crops in other countries as well [source: Borenstein].

Without honeybees to help propagate our crops, there will be a critical shortage to global food supplies - and your dinner plate. Over time, this shortage could spiral out of control and lead to looting and other desperate measures, until famine sets in and the world's population starves to death.

If you've ever cooked for a teenage athlete, then you understand how a bottomless pit works. When it comes to the bottomless space pits known as black holes, however, the mechanics are a bit more complex - and could spell doom for our planet.

Black holes form when stars collapse on themselves and create an abyss from which nothing - not even a shaft of light - can escape [source: Imhoff]. So, if the Earth were to get sucked into one of the 10 million black holes that exist throughout the universe, it could mean curtains for us all [source: ABC News].

The closest black hole that is large enough to swallow the earth lies at the center of our own galaxy, but it's some 27,000 light-years away (that's about 159 quadrillion miles, or 255 quadrillion kilometers) [source: Star Date]. However, scientists have discovered a new threat: There are rogue black holes wandering throughout the universe, entering galaxies and ripping apart planets. Even from a billion miles a way, a renegade black hole could cause the Earth's orbit to change [source: ABC News]. Worse yet, if a large black hole were to come within a few miles of our planet's orbit, its gravitational pull would suck our world right in. The end.

At least the light show would be pretty cool - right up until we all got ripped apart by spaghettification or smooshed into a ball of infinite density.

The Cold War may have ended in the 1980s, but that doesn't mean we're free from the threat of nuclear war. Several countries currently have nuclear warheads in their possession [source: Arms Control Association]. If any of these are fired, the initial nuclear blast could obliterate everything - and everyone - within a radius of up to 30 miles [source: The National Terror Alert Response Center]. Even just one nuclear blast could be powerful enough that survivors worldwide might have to contend with a nuclear winter.

Each nuclear blast pushes massive amounts of smoke, dust and radioactive particles into the atmosphere. In a nuclear winter, this debris would be great enough to blot out the sun, lower the Earth's temperature and cause many of the Earth's life forms to die. The radioactive particles in the Earth's atmosphere would eventually fall, poisoning agricultural lands, water supplies and people. Anyone who survived the initial nuclear blast would need to hole up in a bomb shelter for the first few days of heavy fallout, perhaps as long as a month [source: FEMA]. Even with a stock of canned goods and bottled water, survivors would just be taking a rain check on their death sentence, thanks to the ensuing radioactivity and nuclear winter.

The fallout from this mushroom cloud from the 1954 Operation Castle-bravo nuclear test reportedly affected several thousand miles of surrounding ocean and islands.

Germs are a hardy lot. We've managed to live with these pesky single-celled critters since cave dwellers first sampled stream-fresh sushi, but it's been an uneasy truce. And sometimes our population has been on the losing end of the human/germ war. The Black Plague comes to mind.

Many of the antibiotics that once relegated harmful germs to nothing more than a nuisance have lost their power as bacteria have mutated and produced resistant strains. According to some public health experts, it's entirely possible that a particularly virulent bug could spread like wildfire and wipe out the entire human race [source: Powell]. It's all the more reason to cover your mouth when you cough.

During the 1950s, an entire town in the south of France suddenly suffered hallucinations that caused people to do things like strangle their loved ones, jump out of windows or believe they were being eaten by snakes. No one is certain who - or what - caused the madness, but it's suspected that LSD-, mold- or mercury-tainted bread sold by the local bakery was the delivery method [source: Fabricius]. Think mass insanity couldn't happen today? Maybe it already has.

In 2010, the World Health Organization reported that more than 450 million people around the world have a psychological disorder [source: World Health Organization]. In 2011, the Centers for Disease Control revealed that half of all Americans would develop mental illness during their lifetimes [source: Reinberg]. And by 2020, depression is estimated to become the second leading cause of disability [source: World Health Organization]. Though a poisoning of our global food supply with psychoses-inducing chemicals could send minds reeling and tear the very fabric of society apart, perhaps we're headed toward similar results all on our own.

Scientists at the European Organizations for Nuclear Research (CERN) built an atom smasher 17 miles (27 kilometers) in diameter. While this mega machine - known as the Large Hadron Collider - might sound like a fictional device you'd find in a secret laboratory run by an evil mastermind, it's actually located in Switzerland and staffed by relatively normal folks - if you can stretch “relatively normal” to include “physicists bent on recreating the big bang thought to have created the universe.”

The job of the particle accelerator is to move atoms around its circumference at the speed of light before smashing them together with incredible force. Lawsuits and unexpected repairs delayed the big bang experiment for several years, but on March 30, 2010, the LHC finally experienced the first collisions between particle beams, and it set a world record for the highest-energy manmade particle collision. While the purpose of the LHC is to further scientific understanding of the laws of nature and possibly create new forms of energy, some believe that it has the potential to blow up the world - or create a massive black hole that will swallow the world [source: Wethington]. However, now that the machine has been running successfully, it seems to inspire less fear of catastrophe.

As science projects go, the Large Hadron Collider is a lot more impressive (if a lot more sinister) than a potato battery.

This one is just about as serious as this list will get. This one comes straight from the mouths of high ranking UN officials, government agencies and scientists, and is locked away among thousands of reports that hardly anyone reads. There are a lot of figures that float around in these reports and I could reel them off one by one but it would take ages. Basically it says in three generations there will be half the population on Earth as there is now. And it will keep declining. No its not a virus, there is no prophecy saying that a comet will hit the Earth killing 3 billion people. The truth is as simple as not having enough children. Decades ago people had to have lots of children. The main reason was, the more children you had, the more hands you had to help farm lands, work in shops and look after you when you were older.

Modern technology combined with social programs has replaced our need for many children. We only really have children now because we want them. The problem now is less and less people want children. Maybe because of poor finances; the inability to find a suitable home; whatever. More women work now than ever before so they have children later and bear fewer. 50 years ago women had, on average, 5 children. Today that number is 2.7. On average a couple needs to have 2.1 children (compensating for children that die young) to ensure the continuation of the species. The decline is rapidly reaching that crunch point of 2.0. When that happens the population of the planet will go down. Faster then you think. 3 generations from now the population will be 3 billion. And still falling.

Think of it, We could all die out because we just don’t do enough conceiving. Breed people!

Many of us were convinced that by the time we reached adulthood, robots would fetch our coffee, tie our shoes and make our beds. While we're still waiting for a “Jetsons”-style housebot with superhuman domestic skills, there has nonetheless been considerable progress on the smart robot front, including robots that can operate without direct human instruction (like the Roomba, a disc-shaped robot programmed to automatically vacuum carpets) or reassemble themselves when torn apart [source: Trimble].

And on the horizon? Robots that can act as companions for the elderly while monitoring their vital signs or entertain children while keeping parents in-the-know via built-in cameras [source: Camber]. There are predictions that by 2020, we'll be outwitted by the artificial intelligence that we create [source: McKinney]. Or maybe just swept up by hordes of quick-witted Roombas, once cherished as near pets but then discarded, sold on eBay and bent on revenge.

Be nice to any potentially lethal androids you meet, just in case.