For anyone interested in the idea of humans colonizing Mars, I can thoroughly recommend Kim Stanley Robinsons Mars Trilogy (starting with Red Mars).
It's a great future history of how we might end up there and what it would take for us to ferry millions over (essentially, that we find enough minerals for it to be in bigcos interest to do so).
It's a great future history of how we might end up there and what it would take for us to ferry millions over (essentially, that we find enough minerals for it to be in bigcos interest to do so).