Caleb: Alright, here goes nothing: I don't know what the world's most urgent problem is, but I know which one is going to cause us the most trouble in the long run.
Kate: Which is?
Caleb: Clean, sustainable energy; we need it. According to the U.S. Energy Information Administration, we burn through nineteen-point-six-three billion barrels of petroleum in a single day. I'll spare you the details, but if we continue down this path, following the trend of burning perpetually more, we will kill every living thing on the planet.
Kate: Yeah. It's too bad there is so much money to be made in oil, and that the rich are so short-sighted. Imagine if aliens visited us from outer space and found us using fourth-century technology in a twenty-first-century world. How embarrassing!
Caleb: Aliens? Really, Kate? I'm trying to be serious here.
Kate: ...so am I...