Well.. we have 50 billion years or so before "The Big Rip" is supposed to start happening so we had better get SOMETHING done before then !
Also, within about 15 millions years or so.. our sun is going to die out and bake us to a cinder and then the planet will freeze...
There's an asteroid that's going to fly past the earth closer than most of our communication satelites in a couple years (We'll be able to see it with our naked eye). If it's trajectory happens to be JUST RIGHT, Earth's gravity will alter it's course and make it come back and hit us seven years later. This is the same asteroid that freaked astronomers out several years back when they discovered it traveling between the Earth and the Moon.. a VERY near miss.
Yellowstone National Park is going to erupt someday destroying human civilisation in the process.
If a red giant star goes supernova even within 1000 light years from us, if the gamma ray burst from the collapse of the star hits us, it will fry half the planet and then plunge the other half of the planet into a nuclear winter.
*Holds up his sign saying "REPENT !!! THE END IS NEAR !!!"*
