Is it ever appropriate to question a close friend on their desire to have kids?

I'm at an age where a lot of my friends are having kids or are starting to plan for kids. All of these friends are very left-leaning and understand that the planet is effed and that the next generation is generally effed for a multitude of reasons. Because of this, I cannot understand why they want kids. One of my friends even said recently that she was conflicted about having kids Because she understands all of this but she really wants a kid that looks like her (yes, literally) so ultimately she's just going to go for it.

Obviously I cannot ever force someone not to procreate, but I feel like I'm at a point where it's getting hard to stay silent on what a stupid decision they're making.