h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

They say that if we ever have a nuclear winter all that will survive is bacteria...well at least the polititians will survive.
Actually we are well over due our next E.L.E. as one happens on average every 50 million years or so (the last been 65 million years ago). So everybody get your affairs in order, we could be extinct tommorow
One that you did miss off was supernova's. These can be lethal to life and are a new theory for mass extinctions. The theory goes something like this, every 50 million years or so the rotation of the Milky Way causes our local groups of stars to pass through one of the spiral arms. The resulting gravitational distortion causes stars near the end of there life to explode causing any space around it to be bathed in radiation and cosmic rays. Cosmic rays are neutrons from the dead star accelerated to incredible speeds and they will pass through anything. As they do they cause damage at the cellular level (NASA scientists were worried about this after the early Mercury and Gemini missions) The levels at present are not high enough to cause concern but if a supernova explodes within a few light years of our solar system the effects would be catastrophic, the earth would be bathed in cosmic rays and radiation which would kill every living organism on earth...even the polititians...

Another one you missed is the "gray goo" problem of nanotechnology, first mentioned in K. Eric Drexler's ENGINES OF CREATION. The argument runs something like this: nanotechnology leads to the creation of "assemblers" that can use any matter as raw materials. Without proper safeguards, you could program an assembler to make copies of itself from anything at hand. Eventually some bozo will do so, and that's that...the gray goo of assemblers run amok disassembles everything else to make more copies of itself.

Also, nitpick of the day: "There are no cures for these at the moment and their existence are worrying people silly" ought to be "There are no cures for these at the moment and their existence is worrying people silly" since the subject of the second clause is the singular "existence".

If you REALLY want something to worry about, there's always Gamma Ray Bursters, depression, and boredom. (Usually defined as waiting for H2G2 to load itself!)

I'll agree with that one

Here's another one - scientists in Long Island NY are currently testing a device that will re-create the Big Bang! They have built a facility known as the Relativistic Heavy Ion Collider (known to its friends as the RHIC), which accellerates particles to light speed in order to create a cosmic explosion which emulates what happened when our Universe was created. Of course, the outcome is more likely to be a small little fizzle than a great big universe-generating-super-duper-mega-bang, but keep your electricity bill payments on hold just in case .

You forgot one more! The Big Bang was not real... a big green guy sneezed us out and the day of the great white hankerchief is coming to wipe away the snot!