Adam Frank

It was a telling moment: David Wallace-Wells, author of the new book The Uninhabitable Earth, was making an appearance on MSNBC's talk show Morning Joe. He took viewers through scientific projections for drowned cities, death by heat stroke and a massive, endless refugee crisis — due to climate change. As the interview closed, one of the show's hosts, Willie Geist, looked to Wallace-Wells and said, "Let's end on some hope."

So, it's Election Day here in the United States.

Every presidential election seems important, but I am sure that I am not alone in thinking this one is different, maybe more important than most.

So, please, go vote.

When you're done, I give you (once again) Carl Sagan's beautiful "Pale Blue Dot" speech to put it all in perspective.