I think it is essential for the long-term survival of the human race that we migrate off Earth eventually and start colonizing other planets. Until we do, the human race will remain vulnerable to extinction-level events like nuclear war or another asteroid on the scale of the one that killed the dinosaurs. But there's really no rush, this should be an ultra long-term multi-generational type goal, which probably will take centuries to realize. Trying to rush it and / or use it as an excuse to ignore pollution / climate change is incredibly irresponsible. Let's fix the problems we have here at home, and then more resources can be devoted to space exploration.

But I don't want to see space funding completely slashed. I love science fiction and the romanticized fantasies of living on other worlds & traveling around the universe. I want to see Mars exploration proceed but with realistic goals. Baby steps first. I'm very supportive of a manned mission to Mars sometime in the next decade or two. But not to start a colony. First we've got to get there, put people on the surface, and just see what it takes to do that. Something like the Moon landings to start off (and on a side note, it's an absolute shame that we haven't gotten around to sending people back to the Moon even).

If I live long enough to see a manned mission to Mars, I will die a happy man.