I don't think the climate nazis that think that colonizing other planets is the solution to climate change really exist in any significant numbers and I feel that's really a misunderstanding of what many people are saying or thinking.
On one hand you have climate change and there are many people that think that it is indeed a serious issue worth tackling regardless of the way we want to try and do this. Btw, the link to your climate change post from before has the link twice or something and doesn't really work. Of course, it's easy to copy the correct link manually after you see the 404.
On the other hand, you have the much more distant idea that we can colonize other planets. I think most people out there that are talking about the first and the second have no delusions on which one is more feasible and understand that humanity has only one planet to live on for the foreseeable future and it's this one. Colonizing other planets is something to be done to ensure humanity's survival on a much broader scale than the problem of global warming regardless of agreement or disagreement on the cause, possible consequences and/or possible measures.
I think when most people say we need to do something about climate change and that we need to colonize other planets, they don't mean that we need to colonize Mars, so we can escape our home planet with altered climate. I think most of us realize that even if Earth becomes a disaster zone, it would still be more hospitable to human life, life in general and most importantly larger populations than the barren surface of Mars could be in any reasonable terms for any person alive today.