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

We could perhaps survive all these events and be limited simply by the projected life span of the inner solar system. Whereby in 5 billion years or so, the sun exhausting its easily accessable fuels turns into a Red Giant. Theoreticaly consuming everything out to Mars. Lets hope that we find the escape hatch before then eh?

Yes indeed - Pluto might be quite nice for a while then, although when the contraction phase begins and the sun turns into a little brown dwarf star, we might need to set up home somewhere inside the orbit of Mercury...

Such complicated future travel plans!

I find it more likely that well before the expansion phase begins, humanity will have learned how to download conciousness into quantum foam, bypassing the issue entirely

A supernova occurring within ten parsecs of Earth would produce enough gamma radiation to destroy the ozone layer for several years. The resulting direct ultra-violet radiation from the sun would weaken or kill nearly all existing species. Only those deep in the oceans would be unaffected. Statistical frequency of supernovae suggests that one at the P-T boundary would not be unlikely. While some sedimentary rock samples contain what may be records of short-term ozone destruction (large amounts of NOx gases and C14), this theory has little other evidence either for or against it.

Nice little bit of text from Wikipedia - they've got loads of bits about all five major extinctions that have occurred so far

PT boundary, as in Permian-Triassic?

I thought that the prevailing theory about this at the moment is that it was caused by a combination of basalt flood eruption and a deep sea methane explosion. It increased global temperatures by 10 - 15 degrees.

Woodpigeon