In this modern era of "my dick is bigger than yours" arms race where we are all striving to get the biggest and best we are always striving for new and ingenious ways to destroy ourselves, interesting that we have done this since the dawn of time, maybe it is the inevitable fate of the dominant species to either be destroyed or become a fossilised foot note to history!
Pick a method of extinction get them fast they wont be around long!
1) Nuclear war
2) Environmental Disaster
3) Bird Flu Pandemic
4) Chemical Warfare
5) ELE (Extinction Level Event)
The list goes on and on, we need to recognise that we are but temporary tennants of this world not its owners nor operators, it will quite happily continue without us in it and we will be the forgotten species with the lizard men are scratching around digging up shopping malls and hypothesising about the god "prada" that we seem to worship in these large domed structures!
The future of our species is uncertain we could die tomorrow and this planet would adapt and survive long past our demise!