We didn’t when we started with ozone. There were not the full suite of non-ozone-depleting alternatives to CFCs when people were starting to draft legislation. Additionally, we absolutely DO have the technology to make carbon neutral cement. In fact, we can make carbon negative cement if we store the CO2 emitted during the calcining step (as the cement itself will reabsorb CO2 from the atmosphere over its lifetime). Secondly, on Mars there isn’t much carbonates anyway so you’d use alternatives like polymers or elemental sulfur (this is easier than it sounds) as the binder.
The fact that you don’t think we have the tech (which is different from deploying the tech broadly, which no one did for CFC alternatives, either, until there was policy pressure to do so) is exactly the problem I’m referring to: the engineers and technologists proposing to settle Mars actually KNOW of the technology needed to operate completely carbon free. It’s ironically the environmental activists who lack the knowledge of the necessary technology and therefore propose we have to not have any children around and abandon any pretense to luxury or comfort in order to solve climate change.
I'm not the parent commenter, but you seem smart and passionate enough that I want you to engage with my points.
"Climate change" is a misnomer in that it is a stand-in for a larger set of environmental issues that all have their root in cheap, subsidized consumption. If you become too narrow minded and focus on a small set of factors, say transport emissions and crypto mining costs, you end up losing sight of the interrelationships which actually carry the causal weight of ecological collapse (with or without temperature changes.)
For instance, the most cost-effective carbon sinks we have control over are forests. Rather than doing forest farming to coexist with existing resources, and allowing more variance in our diet even if its caloric volume will have to decrease (something we already have too much of and waste too much food with anyway), we would rather destroy this land for monocropping purposes, which also leads to climate change problems which further feeds ecological collapse. It's a backward set of expectations and it's rooted in our greed.
If the technological means are available like you say they are, and I don't disagree with this, then social coordination problems are what's leftover. You can't use tech to evade them, but you discount them here by saying it's "a different thing". Yet if it's the limiting factor because the technology is already available, then it's the only thing that could matter.
And you can't just process these issues in terms of utilitarian calculus because if you think like a utilitarian, and you aren't in a position of influence, you will weigh out your individual contribution to collective problems as being marginally irrelevant.
This is why some environmentalist moralizing is necessary. Because if individuals don't take satisfaction in just doing the right and virtuous thing, even if it's a sacrifice, even a small one, they won't see a point to contributing to the commons at all.
Technology can stave off the need to make these sacrifices but it can't go on indefinitely. And even if it could, innovation takes time, which as I outlined in my comment to the grandparent post is what makes the difference between delivering energy just in time to turn the climate around, or overshooting until you can't even do that. Slowing down helps.
The fact that you don’t think we have the tech (which is different from deploying the tech broadly, which no one did for CFC alternatives, either, until there was policy pressure to do so) is exactly the problem I’m referring to: the engineers and technologists proposing to settle Mars actually KNOW of the technology needed to operate completely carbon free. It’s ironically the environmental activists who lack the knowledge of the necessary technology and therefore propose we have to not have any children around and abandon any pretense to luxury or comfort in order to solve climate change.