The end is the beginning is the end
There are two major problems in the world right now that scare the bejesus out of me that could lead to Armageddon. Civil/Sectarian war in the Middle East, and the melting of the polar ice caps. Both seem real enough to me to question bringing children into this world for fear of having them live in a world not only worse off than how I found it, but might actually not make it to a natural death because the earth "dies" first. However, after seeing Independence Day, of all things, on TV yet again I came to the conclusion that each end of days scenario can save the other from happening. It's a kind of glass is half full logic as long as I forget the empty half of the glass will kill us all in the process anyway.
I'll start with global warming since that's the one where Independence Day gave me the idea. Aliens were attacking and 1/2 the world was dead and what happened? The rest of the world came together to fuck those aliens up. Hurray! So, what's our alien invasion? The melting of the ice caps and the destruction of every coastal city in the world. When we're all sent back to the middle ages because the earth's pissed off at us, petty things like religion are going to seem a bit, well, petty. And I bet Sunni and Shiite and American get along pretty fine then.
And if civil war breaks out in Iraq the next step would be Iran siding with the Shiites and Saudi Arabia, Syria, etc.. siding with the Sunnis (or do I have that reversed?) as well as the Kurds across the middle east playing some sort of third party stick poker. That's going to be a Middle East version of a world war. When no oil is flowing out the rest of the world will be forced to alternative fuels, not for environmental reasons but because there just won't be enough oil. And perhaps that will force CO2 emissions down thereby stabilizing the earth enough to ward off a global catastrophe the likes of which only Hollywood has seen. Granted the earth will still be absorbing and reacting to CO2 from today a hundred years from now, but optimism is optimism.
As Eric Idle keeps whistling for a smaller and smaller brief case of cash: Always look on the bright side of life!