Do you think any parents have ever known that answer? Before climate change was the Cold War and threat of nuclear annihilation, before that was two major world wars, before that was a string of wars and plagues going back to the beginning of humanity.

If you think climate change is a good reason to not have children you need to stop and reexamine how the media/doomscrolling have affected your thought process.

I see this reason given time and time again and I just don't understand it. We're currently living in what's probably the best time ever to be a human. We get to live in air conditioned houses, many medical issues have been all but eradicated, we have (for the first time ever) too much food, etc.

Otherwise if it's just an excuse - you don't need one to not have children. If you just want to maintain your current lifestyle that's up to you.