Could life in solar system complicate space settlement?

On Fri, Apr 13, 2012 at 2:10 PM, Al Globus wrote:
(...)
> It should be noted that many civilizations have collapsed due to
> environmental degradation.
(...)

On the other hand, others have degraded their environment, the
environment of their colonies and other subject regions, and even
though they prospered and are still alive! E.g., Europe, which *now*
is concerned about the environment, but until the mid 20th century was
an industrial revolution distopia and also explored the resources of a
lot of colonies as if there was no tomorrow. Based on that, I consider
environmental degradation for economic purposes an investment of
medium risk.

Going back to the subject of space exploration, it seems hard for me
to see how for instance deforestation or whatever would be a
survivability issue for colonists, since forests (and even the soil
and air) would have to be made from scratch by seemingly industrial
processes...