That makes sense if we imagine we have some fixed pool of climate fighting energy we can spend in one case or the other but I'm not at all sure why you would wa

That makes sense if we imagine we have some fixed pool of climate fighting energy we can spend in one case or the other but I'm not at all sure why you would want to adopt that model? Climate change on Earth is more a political matter than a technological one and so the PR resources used by Hollywood seem to me to be more applicable to fighting climate change than the engineering resources space exploration uses. But more to the point, we're not actually spending any money on terraforming Mars right now. It's just something people talk about. What we are doing is sending robots to Mars to explore. And hopefully at some point we'll be sending better robots or even human scientists who'll want a pre-assembled base put together by robots. Worrying that the terraforming efforts people might get up to in 50 or 100 years will take away from the steps we need to be making now for climate change is premature.