There are massive intractable problems with human society on earth at the moment which lack easy solutions (poverty, aids, overpopulation, climate change, social order).

Poverty - has always been with us. Many, many people are better off. AIDS - We will solve this. Overpopulation - Population will stabilize at 10 billion. See 2nd link. Climate change - see below. Social order - so long as we don't extinguish ourselves, this will work itself out.

http://www.gapminder.org/videos/hans-rosling-ted-2006-debunking-myths-about-the-third-world/

http://www.ted.com/talks/hans_rosling_on_global_population_growth.html

We might be stuck in the solar system for the next century, but we're certainly not stuck on Earth.

http://www.wired.com/autopia/2012/03/elon-musk-says-ticket-to-mars-will-cost-500000/