Impending doom - news story - 08 Jan 2014
Don't panic
If you've never read Bill Bryson's popular science book, A Short Hisotry of Nearly Everything, I'd recommend it. It does an admirable job of covering a great deal of subjects, but at times it seems like a list of things which could easily go horribly wrong with the world.
One of those potential global disasters is a super volcano, with the famous Yellowstone Park crater as an example. We humans have been trampling around the planet for a very short time in geological terms, and there hasn't been a super eruption since we deemed ourselves civilised. We haven't experienced one, and can only really speculate as to the outcome. But speculation is fun.
This article explains a little about the possible effects and - perhaps more importantly - a few of the possible indications something superbad is about to happen. Give you time to pack all your stuff and make for the moon. Don't say you weren't warned.