For the longer term, it is hugely beyond our technological abilities

We could start colonizing Mars using nuclear rockets in 20 years, if we wanted to. Heck, if we wanted to badly enough, we could start it in 20 years with chemical rockets.

whatever determines our survival as a species for the nex millennium will be decided on earth. And we are struggling with that right now.

Certain things will be decided in the next century. We could colonize Mars with agriculture but without terraforming well inside that. When it comes to an issue like "species survival" I think the expense and redundancy are justified. Whether or not western civilization decides to colonize Mars will be one of those deciding factors. The colonization of Mars would be a turning point in human history as significant as the european colonization of North America, with political and economic consequences as large and as far-ranging. Perhaps it would be better if western civilization did not choose to colonize Mars. I'm fairly certain Chinese civilization will do so, and having both powers vying for new territory could well result in war.