Oddworld Forums - Doomsday scenario's

I was bored, checking the forum and thought: hey, why not a new topic. So I was thinking about what and then I got an idea, doomsday scenario's. For those of you ignorant of what a Doomsday scenario is, let me give a quick overview.
A doomsday scenario is an event, or a series of events, that lead to the destruction of the earth, its population, both or just a large part of the population. Now, doomsday scenario's can be divided into three main
categories:

Natural occurrences:

* a global pandemic (a pandemic is a HUGE epidemic.) Think a global outbreak of cancer. Good fictional examples are the T-Virus from Resident Evil, or the Krippin Virus from I Am Legend.

* a geological event such as massive flood, basalt volcanism or the eruption of a supervolcano. One such event, the Toba Eruption, occurred in Indonesia about 71,500 years ago. According to the Toba catastrophe theory, the event may have reduced human populations to only a few tens of thousands of individuals.

* a gamma ray burst or other devastating blast of cosmic radiation. One especially deadly hypothesized source is a hypernova, produced when a hypergiant star explodes and then collapses, sending vast amounts of radiation sweeping across hundreds or even thousands of lightyears of space. Hypernovae have never been observed; however, a hypernova may have happend before. The nearest hypergiant is Eta Carinae, approximately 8000 lightyears distant.

* an abrupt reorientation of Earth's axis of rotation. (which would kill us by making us all dizzy causing us to fall of the earth which is flat ;).

* a drastic increase or decrease in the Sun's energy output.

* an impact event caused by the collision of a large meteoroid, asteroid, or comet with Earth. A common theory postulates that the extinction of the dinosaurs occurred approximately 65 million years ago as a result of the extinction event when a large asteroid struck the earth, producing atmospheric dust which blocked solar energy and caused a significant lowering of temperatures worldwide. Evidence for this theory includes a sedimentary layer of iridium in the geological record and a large crater in the area of Chicxulub, Mexico. The Tunguska event (1908) was on a much smaller scale.

* a sudden change in the physical constants governing the universe, such as that created by a Vacuum metastability event[6]

* the effect of a black hole on the planet Earth.[7]

* a universal Big Rip or Big Crunch. Think of these as a balloon filled with and dust, were the dust and the air is space. The Big Rip happens when you grab the balloon (good luck with that:p) and pull it apart. A Big Crunch means you just push the balloon until is pops.

Non-natural events

* the creation of a black hole on or close to Earth. Think of a vacuum cleaner and some dust. Were the dust the vacuum cleaner is the black hole.

*a nuclear or biological war. Think WWIII

* a cybernetic revolt. Think I,Robot.

* a grey goo event. Grey goo is the theory of uncountable nano-bots replicating themselves and taking over the earth ^^.

* alien invasion. Think... E.T. ^^.

Supernatural events:

* an act of divine retribution or the Last Judgment. Many religions include beliefs pointing to the end of time. The Norsemen believed that the world would end in a tremendous battle of the gods known as Ragnarok. In the Christian Bible, the Book of Revelation describes Armageddon, a final battle between the forces of God and the forces of Satan. Think of will-never-happen.

Humanity caused event:

*Antibiotic resistance
Natural selection would create super bacteria that are resistant to antibiotics, devastating the world population and causing a global collapse of civilization.

*Gulf Stream shutdown
There is some speculation that global warming could, via a shutdown or slowdown of the thermohaline circulation, trigger localised cooling in the North Atlantic and lead to cooling in that region. This would affect in particular areas like Ireland, the Nordic countries, and Britain that are warmed by the North Atlantic drift.

*Demography
Demographic trends create a flood of babies and a lack of adults to supervise them that threatens the order of civilization. Think about losing all people above 20 years old.

*Mutual assured destruction
A full scale Nuclear war could kill billions, and the resulting nuclear winter would effectively crush any form of civilization.

*Dysgenics
The ideas of dysgenics suggest that the average individual in a civilization may eventually become weaker, because the most intelligent reproduce least leaving the population less able to perform higher functions. Think about this.
We all know there are popular kids and nerds. Nerds tend to reproduce less and the dumb popular kids more. This leads to an overal dumb population unable to do stuff like being a doctor or operating companies and eventually turns us back to cavemen.

*Finance
Markets fail worldwide, resulting in economic collapse: mass unemployment, rioting, famine, death, and cannibalism. (This scenario happened, to some extent, in the 1930s and 1940s, helping to cause a major war that has, so far, been the only war to involve nuclear weapons. That war (along with its its immediate precursor in Asia) also involved major atrocities and genocide. Such a scenario, in an age of ICBMs and hydrogen bombs, might be even worse in the future.) Think Wall street collapse.

*Overpopulation
Some scenarios of simultaneous ecological (food & water production) and economical (see below) collapses with overpopulation are presumed to lead to a global civil war, where the remaining habitable areas are destroyed by competing humans (so called 'Mad Max'-scenario). Simplified: the earth can only sustain (in theory that is) 20 billion people. Were currently with 6 billion.

*Peak oil
Oil becomes scarce before an economically viable replacement is devised, leading to global chaos and discomfort. Think losing all oil RIGHT now.

*Experimental accident
The unlikely creation of a hypothetical microsingularity or exotic matter in particle acceleration experiments, or some unanticipated experimental accident, resulting in destruction of the planet or a large scale disaster. An (unrealised) example was that the first test of an atomic weapon might lead to ignition of the atmosphere and global destruction. Simplified: we create something of which one gram is enough to destroy Europe. And someone accidently (accidently yeah, sure) creates a kilo. Bye bye earth.

All of this was quoted from the Wikipedia and can be found on the page: Doomsday Event and attached pages ^^. Edited for your convenience.

Nice theories, but most are unlikely. Except a few, which are lined out here.

Economic collapse (thank wings of fire)

Peak oil (once again wings of fire, thanks man.)

Big things hits small earth ^^.

So what do you think? Whats your favorite, and what would you do if one of these were to happen? All that, and more. Oh and don't get nightmares ^^.