Of course we must address problems here at home, but we should also think in the long term; that's why I work with Icarus Interstellar on cultural and genetic issues involved in long-term space settlement. A billion puzzle pieces must be assembled to make such futures real, and this is how we start...by starting!
You can hear more at my recent talk at the Perimeter Institute for Theoretical Physics or read about these ideas in my book, Emigrating Beyond Earth.
Below, Sagan weighs in:
Arthur C. Clarke in 1950:
There is no way back into the past; the choice, as Wells once said, is the universe—or nothing. Though men and civilizations may yearn for rest, for the dream of the lotus-eaters, that is a desire that merges imperceptibly into death. The challenge of the great spaces between the worlds is a stupendous one; but if we fail to meet it, the story of our race will be drawing to its close.
...and Isaac Asimov in 1974:
Unless we are willing to settle down into a world that is our prison, we must be ready to move beyond Earth. . . . People who view industrialization as a source of the Earth's troubles, its pollution, and the desecration of its surface, can only advocate that we give it up. This is something that we can't do; we have the tiger by the tail. We have 4.5 billion people on Earth. We can't support that many unless we're industrialized and technologically advanced. So, the idea is not to get rid of industrialization but to move it somewhere else. If we can move it a few thousand miles into space, we still have it, but not on Earth. Earth can then become a world of parks, farms, and wilderness without giving up the benefits of industrialization.