Yep it is difficult to see human beings changing their ways quickly enough to save the planet be it in 12 or 30 years. Somebody mentioned world war which could be very well a consequence of nations fighting for and over scarce resources. World war in a perverse sense could be a quick but nasty way of saving mankind. Once the dust had settled (probably radio active stuff) the few humans who survived would have the planet to themselves and hopefully start making a better fist of it this time learning from the mistakes of the past. This could very well be our future. We could really do with the equivalent of someone/ something banging our collective heads together as a species to get it all sorted.