Shouldn't this be in Chit-Chat or something? It doesn't seem like a serious debate topic. :/
If the world ends, I've no clue how it will happen. However, almost every single apocalypse theory is completely baseless, founded on incorrect science or is just simply ludicrous, like the whole 2012 thing.
Also, I doubt it will be due to humans. If there's one thing the fools who come up with apocalypses agree on, it's that humans will be the cause of it.
HEY BUDDY. /shot
Global Warming or Political Corruption will make our earth look like a Call Of Duty battleground.
I assume you mean how human civilization will end? Cause the earth can take a hell of a lot. My guess would be some kind of natural disaster, like the theory about the asteroid that wiped out the dinosaurs. We can survive global warming with heat control like AC (plus the earth is supposed to warm up, we're technically in an ice age - and plenty of people live on the equator and are fine with the heat), we can deal with epidemics with isolation/medicine/etc (again, tons of people could die but that doesn't mean we'll be wiped out, look at the Black Plague), the dead aren't going to rise and kill us, but if a huge asteroid hits the earth we're pretty much all done for. This is probably a little biased based on I just watched Dino Week on Discovery, but all the things that asteroid caused (extreme heat, extremely fast-moving debris, earthquakes, volcanic eruptions, massive fires, a dustcloud covering the entire earth blocking out the sun and making it extremely cold, lots lots more) we'd be fighting every conceivable natural disaster at once and would be done for

Real quick, i believe scientists have said that we are DUE for an iceage, not that we are in one. (cant 100% hold me to that, i believe it was said on the History channel though when they had the iceage special.)
Also, the human race is resilient as shit when it comes to survival, we are like a virus.
I'm thinking something along the lines of warfare. But then again, I watch my boyfriend play Call of Duty waaaay too much these days. My completely improbable belief? Zombies. So I also watch him play Nazi Zombies all the time and prepare myself for possible zombie invasions. Lame, I know. xD
I honestly don't remember where I heard it, but I believe the fact that some parts of the world have permafrost means we're still in an ice age. It makes sense - the earth is warming up (and we're blaming ourselves, which while it contributes to it, isn't the main reason) and the entire planet used to be basically tropical (think dinosaur era)

"Permafrost will typically form in any climate where the mean annual air temperature is less than the freezing point of water. Exceptions are found in moist-wintered forest climates, such as in Northern Scandinavia and the North-Eastern part of European Russia west of the Urals, where snow acts as an insulating blanket. The bottoms of many glaciers can also be free of permafrost."
Just found that on a website.
The global warming is being sped up because of us, but its not like we are going to fry, its just that the earth is just going to have to adjust. Our little rock can take almost anything we throw at her (unless we nuke her core).
Definitely agree with you on the global warming thing - it's not even a threat. We already deal with hot summers in many parts of the world, the earth has been hotter than it is now and has taken on waaaay more disasters than slow temperature change, and all the hype about it is absolutely insane

I hate to say it but I thing the world will probably end in a war. Something about humanity is messed up, look at how many conflicts take place every day. There's constant bloodshed in some parts of the world.
Eventually it'll come to a head when one crazy world leader gets their hands on a super weapon of comic book magnitude. The other world leaders will move to stop them, and the crazy person will hit the big red button dooming us all.
Or zombies. And honestly, I'm more afraid of the zombie apocalypse that any other scenario. ;-; Do not want flesh eating dead people walking the earth.
[flower=RedSekhmet]
The world will end of insanity, starting from you and me! Maybe annoyance. Spread it around and the world will someday end.
XD Sorry, I am reading everyone's posts, it's just a little too much XD DUH. ....I lost the game XD
Personally? I think it'll be by some mass, quick spreading infection that causes humans to become mindless animals (think 26 Days Later). There are already parasites that can infect a rat's brain into making it seek out cats. Easy food. Now image this, but in humans. And what will humans eat? Other humans.
Books I Own On The Subject:
The New Dead Living Dead Living Dead 2 Brains ZOMBIES! A Record of the Year of Infection Dawn of the Dreadfuls Pride and Prejudice and Zombies The Zombie Handbook World War Z The Zombie Survival Guide Zombies For Zombies I Am Legend (this one can be subjective)
The article about the brain parasite can be found here.
Darwinism. Darwinism at its finest.
[small]Probably something plausible.
Not like a zombie apocalypse. Probably not even a realistic viral or bacterial thing at all. A contageous disease might kill a majority of a population but rarely the entire species. Even HIV/AIDS can't wipe out an entire human population because some people have been found to be immune to it. Same goes for contamination of resources, diminishing food supply, overpopulation. That might kill alot of people, as it already does, but not everyone.
The idea of a total apocalypse and absolute destruction of the planet is religious fetish anyway. In my opinion.
I reckon we'll have another ice age or something. We're pretty much overdue for another one by several centuries. Eh. We'll probably evolve to be taller with huge heads and no hair. Life goes on even if none of us witness it. [/small]
I'm going to die and then the world will effectively cease to exist. Right? Since "the world" only exists in my mind and what it processes.
But I don't think that's what you mean.

My Idea is that the world will over populate and then global warming. After the world has lost land, a huge war will break out for the remaining territory. Because the dumb politicians will still be in power and it will be just new systems of power; like dictatorship in America.
I think that an asteroid/meteor is more plausible than really any of the above. Also OP, you totally reminded me of iRobot with the nanobots lol
Lurking like lurkers do...