It's the end of the world as we know it.

[The_Yoda]

SvennoJ said:

LegitHyperbole said:

The idea that the atmosphere stays the same is pretty ridiculous, we had environments with such oxygen that allowed spiders to grow to the size of dogs and centipedes so big they'd eat a cow. 

Ever played SimEarth? You can simulate your own climates.

I made an oxygen rich world with perpetual fire. A ring of fire sweeping around the planet without ever stopping. Stuff growing back fast enough for the next lap. I made a circular land mass around the equator to get that going.

I wonder what forest fires were like when oxygen was that high in the past! (35% 300 million years ago, currently 21%)

I'll bet the Dimetrodon were able to gamble all night long at 35%.